About us

The Bristol Knee and Sports Injury Clinic provides expert help to anyone who is suffering from joint problems, sports injuries or pain. We treat the full range of orthopaedic problems and offer comprehensive diagnostic, surgical, physiotherapy and rehabilitation services. If you are suffering from a joint problem or sports injury you can book a consultation and receive treatment from us directly as a self-paying patient, private insured patient or you may be referred by your general practitioner or insurance company.

You can find out more about each member of the team in this part of the site.

Research

  1. The Anatomy and Biomechanics of the Patellar Tendon

    The Anatomy and Biomechanics of the Patellar Tendon

    O Basso and D P Johnson

    Although it has been suggested microscopic ruptures in the central region of the tendon are the cause of patellar tendonitis, and the patellar tendon is increasingly used to provide the autogenous graft for the reconstruction of the anterior cruciate ligament, little is known of the detailed anatomy or biomechanics of the tendon. Therefore a detailed description of the cadaveric anatomy of the patella tendon and an investigation into the biomechanics and functional behaviour of the tendon was undertaken.

    Ten specimens of cadaveric human knee joints were dissected and the anatomical parameters measured. The macroscopic appearance of the anterior and posterior aspect of the patella tendon were assessed and photographed. The origin, insertion and orientation of the Patella Tendon fibres was described and mapped in detail. In a further five knee specimens the functional biomechanics were analysed by measuring the length changes of tendon during eccentric loading of the instrumented specimens on a test rig using Linear Variable Displacement Transducers (LVDT).

    Additional experiments included analysing the tension generated within the tendon during functional loading of the knee specimens within the test rig using specially manufactured buckle strain transducers. The anatomical findings and the biomechanical behaviour of the tendon was related to the local surgical pathology and related to the technique of surgically harvesting the patellar tendon graft from the tendon.

  2. Anterior Cruciate Ligament Reconstruction in the Over Forty Age Group

    Anterior Cruciate Ligament Reconstruction in the Over Forty Age Group

    D P Johnson

    The aim of this study was to analyse the use of a bone-patella tendon-bone autograft for the reconstruction of the anterior cruciate ligaments in patients with persistent instability and restricted function over the age of 40 years. A prospective review of utilising an arthroscopic assisted technique, utilising a 10mm autograft secured with Interference Fit Screws. A consecutive group of 14 patients over the age of 40 years at the time of surgery was compared with a concurrent series of 50 patients under the age of 40. Regular post-operative clinical and radiological review was undertaken. Objective laxity testing was undertaken by one observer using a standard protocol.

    The mean age of this population was 44 years (range 40 to 51 years). Follow up was obtained in all patients for a mean 19 months. This group of patients was compared with a group of 43 consecutive patients mean age 29 years. The results demonstrated that all patients over the age of 40 obtained subjective and objective stability of their knee. When asked 98% under the age and 100% of patients over the age of 40 considered their knee to be good or excellent. One patient under the age of 40 had clinical giving way and a failed graft. Clinical laxity measurement using the KT1000 Dynamometer demonstrated a normal laxity of less than 3mm in 91% of patients under the age of 40 and 100% of patients over the age of 40. 2% of patients under the age of 40 had a measurement of greater than 5 mm, confirming a ruptured graft. Clinical analysis demonstrated all patients in the group over 40 to have a negative pivot shift compared with 7% of patients under the age of 40 having an abnormal pivot shift examination. Analysis of the pre and post operative Lysholm score demonstrated an improvement in both groups. International Knee Documentation Committee Scoring analysis demonstrated a normal or nearly normal score in 93% of patients under the age of 40 compared with 100% of patients over the age of 40.

    In conclusion we would suggest that these patients were able to undertake a normal rehabilitation and obtain a full range of motion. Utilising this graft resulted in excellent subjective and objective stability. Anterior knee pain was only present in 7% of patients and not associated with any restriction in function. Although none of the patients in this group required reconstruction for posterio-lateral rotary instability or for excessive varus, these factors must be considered prior to undertaking reconstruction in this population.

  3. Operative Complications From the Use of Biodegradable Kurosawa Screws

    Operative Complications From the Use of Biodegradable Kurosawa Screws

    D P Johnson

    The development of interference fit screws allowed the secure fixation of the bone tendon bone patellar tendon graft in arthroscopic anterior cruciate ligament reconstruction. This procedure has become regarded as the gold standard for anterior cruciate ligament reconstruction. However complications of their use are common and include graft damage during insertion or impingement in flexion, screw protrusion, screw loosening, inadequate graft fixation, infection and tenderness around the tibial tunnel. Screw removal is sometimes necessary as a secondary procedure.

    Biodegradable implants have been used in other sites particularly in the area of fracture fixation. The commonly used materials are polyglycolic and polylactic acid in varying composites. These materials have been demonstrated to be biocompatable although a very small incidence of chronic granulation and occasional sinus formation has been reported. Bioabsorpable interference fit screws have been designed for use in arthroscopic anterior cruciate ligament reconstruction. Although brittle with a pull out measured at 10% less than metallic screws, their use has many potential advantages. This study was performed to analyse the operative use of these screws./ A prospective randomised and controlled trial was performed on 50 patients undergoing arthroscopic anterior cruciate ligament reconstruction by a single surgeon. Patients were analysed clinical and radiographically pre and post-operatively. Haematological inflammatory markers were measured, KT 1000 assessment was undertaken as was the speed of their recovery and return to sporting activities.

    The results demonstrate that the use of these screws required several modifications to the operative technique as one screw fractured and five cracked during insertion, but once the technique is mastered no further operative failures occurred. Recannulation of the screw with the screw driver proved difficult. The metallic screws were noted to have a higher incidence of graft damage during insertion and a higher incidence of tibial tunnel tenderness, although to date none has been removed. No peri-operative infections or failed primary wound healing occurred in either group and no significant differences were noted in the speed of recovery, haematological inflammatory markers, and bone tunnel diameter to date. The use of bioabsorpable interference screws can safely be undertaken with many advantages. However modification of the surgical technique is necessary to safely utilise the brittle and blunt bioabsorpable screws.

  4. The "Comma" Sign Following Arthroscopic Anterior Cruciate Ligament Reconstruction

    The “Comma” Sign Following Arthroscopic Anterior Cruciate Ligament Reconstruction

    Basso O, Johnson D, Jewell F, Wakeley C

    Following arthroscopic anterior cruciate ligament (ACL) reconstruction using the bone-patella tendon-bone (BPTB) graft technique, radio-opacities were noted on the lateral and postero- anterior post- operative radiographs of the operated knees. A stripe of radio- opaque material of curvilinear shape, resembling a comma termed the Œcomma¹ sign occupied an area in close contact with the lateral femoral condyle. The records and radiographs of 50 consecutive cases of BPTB – ACL reconstruction were reviewed and the radiological features of the radio- opacities were defined. The roentgenographic and clinical findings were correlated.

    The results demonstrated that there was no statistically significant difference between the patients presenting the radio-opacity and those without it, in terms of loss of motion at six, twelve, twenty- six and fifty- two weeks postoperatively (P>0.50). Assessment of the roentgenographic progression, made on a second set of radiographs taken between 3 and 6 months postoperatively, disclosed that this radio- opaque material tended to disappear early in the postoperative period. No correlation was found between presence of radio- opacities and other postoperative clinical features such as duration of pain, effusion, analgesia requirement, discharge timing, time to driving and time to work. A protocol of postoperative early weight- bearing mobilisation had been followed in all cases which may have played a role in promoting the faster dissolution of the debris.

    The “Comma” sign was deemed to have been caused by the swarf and cancellous debris, produced by arthroscopic drilling of the femoral screw hole, which accumulated in the postero- lateral joint space as a result of the figure- of- four position of the leg during drilling. The debris did not result in any pain, additional swelling, loss of motion, arthrofibrosis or delay rehabilitation compared to a normal group of patients. Nevertheless, it is recommended that, following endoscopic ACL reconstruction, a thorough irrigation of the postero- lateral compartment be routinely carried out.

  5. Treatment of the Cruciate Deficient Degenerative Knee

    Treatment of the Cruciate Deficient Degenerative Knee

    David P Johnson and M Mansfield

    Increasingly we are presented with a young 30 – 50 year old adult with early articular degeneration resulting from a chronic anterior cruciate ligament deficiency, articular damage and menisectimy. An analysis was undertaken of six such patients two years after undergoing a procedure which combined a lateral excision wedge high tibial osteotomy fixed with a lateral staple was combined with an extra-articular anterior cruciate biceps tendon tenodesis between the anterior aspect of the fibular head and the isometric point on the lateral aspect of the femoral condyle.

    No peri-operative complications occured. Hospitalisation was for three days. Immobilisation was for six weeks in a plaster cast. Union of the osteotomy occurred in all cases, and a full range of motion was obtained by three months. At two year review, all patients had significantly improved function from their knee, the Tegner activity score increased from 4.2 to 5.8 (p<0.01) and 50% had returned to some sporting activities. Two of the 6 patients were completely pain free, four experienced mild activity related pain. All patients had lost their symptomatic knee instability, and wore no external support. As perhaps expected, objective clinical evidence of anterior cruciate laxity was present in all the knees.

    Though excellent subjective results can be expected at two years from this new procedure, the extra-articular tenodesis objectively stretches with time, even in this intermediate activity population. Further efforts will be undertaken to combine the high tibial osteotomy with a more lasting intra-articular anterior cruciate reconstruction.

  6. Anterior Knee Pain in Athletes: Surgical Management

    Anterior Knee Pain in Athletes: Surgical Management

    David P Johnson

    Optimum knee function is of vital importance in a wide variety of sports. Knee stability is important in runniing, twisting, jumping and pivoting. Injuries to the knee are very common because of the lack of bony congruity and its reliance on muscular and ligamentous support. Knee injuries are the most common serious injury during sporting activities.

    Anterior knee pain affects 29% of adolescent children (Fairbank 1984). This may be related to the increase in structured sporting activity which occurs at school during early adolescence. Anterior knee pain is particularly prevalent in certain sports which include basketball, netball, athletics, skiing and cyclling. In these sports activities are undertaken whilst the knee is in a flexed position, and or jumping is common. To understand the patho-mechanics of anterior knee pain, the anatony, clinical examination and mechanics of the knee must be well understood. Much of the confusion surrounding anterior knee pain has been produced by the inability of the practitioner to translate distinct clinical problems into a specific classification. This applies whether they be a general practitioner or hospital consultant (Ref).

    FUNCTIONAL ANATOMY OF THE PATELLO-FEMORAL JOINT

    The anatomy of the knee can be broadly divided into the three joints; the patello-femoral articulation, the medial and the lateral tibio-femoral joints. To understand the pathology of anterior knee pain this disctinction is very important. The weight transfer across the tibio femoral joint is aided by the menisci which distribute the compressive forces and reduce pressure on any particular point. The patello femoral joint bears little load whilst standing with the knee in extension. The patello-femoral contact force is greatest between 30 and 70 degrees of knee flexion (Ficat et al.). During flexion the site of contact on the patellar changes. The area of contact of the patello femoral joint increases during knee flexion. These mechanisms assist in dissipating the extra loading on the patello femoral joint during flexion. None the less when descending stairs, jumping or landing as in netball and basketball the compressive load across the patello-femoral joint may reach five times the weight of the body (Ficat et al).

    The articular cartilage on the patella is up to 5 mm thick; thicker than anywhere else in the skeleton. Besides allowing unresisted motion the funtion of the articular cartilage is to help dissipate the compressive forces and prevent excessive loading on the subchhondral bone plate. Such pressure is interpreted as pain. Generally it is the extreem forces experienced by the patello-femoral joint during sport result in the high incidence of anterior knee pain in athletes.

    PATHOMECHANICS OF ANTERIOR KNEE PAIN

    The patella has a very important function in the mechanics of the knee. The patella increases the moment of action of the quadriceps expansion and increses the extensor force by a factor of two to threefold (Ref). In the absence of the patella, such as following patellectomy, the strength of the quadriceps muscle is diminished by at least 30%, the tibio femoral compressive force is increased and degenerative change within the tibio femmoral joint is increased (Ref).

    ANTERIOR KNEE PAIN AS A SYMPTOM

    It is important to realise that anterior knee pain is a symptom and not a syndrome. It is insufficient for a clinician to make a diagnosis of anterior knee pain as many different casuses have been identified. Whilst it is true that in almost all cases of anterior knee pain an initial period of quadriceps strengthening exercises, physiotherapy and non steroidal anti-inflammatory medication will be prescribed. A provisional pathological diagnosis as to the cause of the pain will give guidance to the physiotherapist, podiatrist, sports trainer and coach. A provisional diagnosis will enable the options for treatment to be discussed with the patient and therapists, the surgical options can be idiscussed for those cases which do not settle following the initial course of conservative treatment.

    To make a provisional diagnosis the clinician should acurrately identify the activity which precipitates the pain, the charachter of the pain and the angle of knee flexion at which the pain is worst. Commonly patello-femoral pain is exacerbated by activities such as descending or ascending stairs, rising out of a chair or driving. These are the activities in which the patello-femoral compressive forces are highest. Any associated clicking, giving way or episodes of patello-femoral instability of the knee should be identified. The exact site of the pain in the front of the knee must be determined, whether iit is n the supra-patellar pouch, medial or lateral retinaculum, retro-patellar, at the inferior pole of the patella, medial or lateral part of the fat pad, the anterior horn of the menisci or tibial tuberosity. Thus the history must be detailed and concentrated on the symptoms pertaining to the patello-femoral joint.

    CLINICAL EXAMINATION IN ANTERIOR KNEE PAIN

    Anterior knee pain in athletes may be caused by extraneous problems. In runners and athletes in general, analysis of shoe wear is important. Badly worn shoes or poorly designed shoes may produce excessive foot pronation and exacerbate any tendancy to flat feet which may precipitate anterior knee pain. The running or playing surface may also be important, particularly when excessive road running is undertaken. In these cases the pain may be helped by running predominantly on grass rather than on roads. Podiatric advice may be helpful and despite the reluctance of clinicans to consider podiatry it is usually easier, cheaper and painless when compared with surgery.

    Clinical examination should include examination of the feet, ankles hips spine and the contralateral knee for stiffness, pain or a clinical deformity. Common clinical pitfalls often mised above the knee are the painful stiff hip, trochanteric bursitis, lumbar stiffness, spondylolysthesis and tight hamstring muscles. Below the knee shin splints, stress fractures, ankle stiffness and flat feet may be related to the anterior knee pain. Congenetal multiple ligamentous laxity should also be specifically sought at it has a significant effect on the treatment of anterior knee pain. / At the knee the usual examination should be undertaken to exclude meniscal or ligamentous injuries and early arthritis. The range of motion and alignment of the limb in terms of varus and valgus deformity at the knee must be determined. Special attention must be paid to palpate the anterior part of the menisci to exclude an anterior horn meniscal tear. This is best done with the knee in the position of flexion. One should also be aware that both anterior and posterior cruciate ligament injuries may present with anterior knee pain.

    Examination of the front of the knee necessarily needs to be detailed and accurate. Inspection may detect swelling as seen with prepatellar bursitis or Osgood Schlatters disease in which the tibial tuberosity is swollen. An effusion indicates an intra-articular pathology. Palpation should start in the suprapatellar pouch and move down the patellar retinaculum either side of the patella into the fat pad which lies to either side of the patella tendon. A tender synovial fold or plica may be palpated in this region arround the patella. I then prefer to palpate the tibial tuberosity followed by the patellar tendon and the inferior pole of the patella; the site of tenderness in patellar tendonitis.

    I then palpate the patella. The superficial surface is easy whilst the posterior surface may be palpated by displacing the patella to the medial side and palpating the exposed undersurface and repeating the manouvour to the lateral side. The patella should then be compressed against the femur as it is gently moved to the medial and lateral side and up and down. This manouver may detect crepitus and roughness within the patello-femoral joint, pain may also be elicited. The patello-femoral joint should also be compressed as the knee is flexed. This may elicit crepitus, and this test may also reproduce the pain experienced. / If patello-femoral subluxation or dislocation is suspected, the apprehension test is performed in which the patella is displaced laterally whilst the knee is extended. Apprehension may be produced by the fear of an impending dislocation and the knee is involuntarily flexed to prevent the patella subluxing. This test is usually negative if dislocation has not previously occured. If the excursion of the patella to the lateral side is restricted by a tight lateral patellar retinaculum, lateral patella hyperpressure syndrome may be suspected in which the tight lateral retinaculum tilts the patella laterally during flexion compressing the lateral side of the patello-femoral joint causing pain.

    RADIOGRAPHY OF THE PATELLO-FEMORAL JOINT

    The plain antero-posterior and lateral films are not ideal for pathology suspected of being in the patello-femoral joint. Although the anterior-posterior view may demonstrate a bipartite patella in which the patella develops in two parts. The lateral view of the knee may demonstrate patella osteophytes although this is usually only at a fairly advanced stage of arthritis. The lateral view may show a patella alta (high patella) which is associated with patella subluxation and dislocation, or a patella baja (low patella) associated with retropatella pain and arthritis. Osgood-Schlatters disease in which partial separation of the tibial tuberosity apophysis, or Sinding Larsen Johansen’s disease at the inferior pole of the patella may also be identified.

    The best radiograph for the demonstration of patello-femoral pathology is the skyline view taken in 30 degrees of knee flexion. This demonstrates subluxation, patella tilt, lateral patella hyperpressure and any arthritis or thining of the articular cartilage. Further information may be obtained by repeating the skyline radiograph at 60 and 90 degrees of knee flexion. The concept of patello-femoral tilt was described by Lauren and he described the lateral patello femoral angle. In the prescence of patello-femoral tilt, this angle which is usually positive, may be reduced as the patella tilts. Patello-femoral tilt may or may not exist with radiological subluxation in which the patella is displaced laterally.

    Arthrography although able to show synovial folds within the joint is not now commonly used as scanning techniques reveal much more information.

    Computerised Axial Scanning (CAT) scanning of the patello-femoral joint has been superseed by Magnetic Resonance Immaging (MRI). MRI is the immaging technique which reveals most information in patello-femoral pathology. The relationship of the patella to the femoral trochlear is well shown. Any synovial folds or plicae in the patella retinaculum or fibrosis of the fat pad may be seen. Occasionally intra-articular tumours are demonstrated. Using saggittal or coronal sections defects in the articular cartilage can be shown on the patella or femoral trochlear. Other conditions particularly those associated with soft tissue inflammation such as patellar tendonitis are clearly defined.

    Reflex sympathetic dystrophy may affect the patella after a minor injury or surgery. This condition is difficult to diagnose but may result in chronic knee pain and stiffness of the knee. A radioisotope bone scan demonstrates a charachteristic increased uptake.

    CLASSIFICATION OF ANTERIOR KNEE PAIN

    Patello-femmoral disorders causing anterior knee pain were well classified by Merchant in1988. The classification divides the causes of anterior knee pain into acute trauma, repetitive trauma, the late effects of trauma, patello-femoral dysplasia, ideopathic chondromalacia, osteochondritis dissecans, synovial plica and patello-femoral arthritis.

    PATELLO-FEMORAL DYSPLASIA

    The most difficult area of classification is dysplasia of the patello-femoral joint. Patello-femoral maltracking is a clinical sign which is exceedingly difficult to describe, quantify or classify. It is best seen while the knee is flexed while the examiner stands above the knee and looks down along the patello-femoral joint. In normal situation the patella follows a straight course as the knee flexes. The patella moves down in to the femoral trochlea groove and into the intercondylar region. In lateral maltracking the patella may move laterally particularly in the first 20 to 30 degrees of knee flexion before then moving medially to enter the patello-femoral groove. The patella may or may not again move laterally beyond 70 degrees of knee flexion. This may be associated with an increased tibio-femoral ‘Q’ angle and external tibial torsion. Lateral patella tracking is associated with anterior knee pain and chondromalacia although the relationship has not been clearly defined.

    LATERAL PATELLAR HYPERPRESSURE

    As described this condition in which excessive tightness in the lateral retinaculum produces lateral tilt and excessive compression in the lateral facet of the patello-femoral joint. The sky line radiograph taken at 30 degrees of knee flexion may show lateral tilt of the patella onto the lateral facet. This condition is associated with and possibly produces chondromalacia patella on the lateral patella facet and eventually produce lateral facet osteoarthitis of the patello-femoral joint. This is one of the conditions in which lateral release of the patella may have good results and possibly prevent the progression to arthritis of the patello-femoral joint.

    PATELLO-FEMORAL SUBLUXATION

    Patello-femoral subluxation may be obvious when the patient recounts episodes in which the patella partially dislocates prior to relocating in the patello-femoral joint. Alternatively, the knee may have a feeling of being weak or giving way particularly whilst descending stairs or during sporting activities. Clinical examination may reveal lateral subluxation or lateral patello-femoral tracking. Additional signs such as patella alta, hypoplastic lateral femoral condyle, increased femoral-tibial ‘Q’ angle, persistent femoral anteversion, external tibial torsion or multiple ligamentous laxity may be present. Clinical examination may reveal a positive apprehension test. Sky line radiographs taken at 30 degrees of knee flexion may demonstrate patello-femoral tilt or overhang. The sky-line radiograph may demonstrate overhang of the lateral border of the patella beyond the lateral femoral condyles. The patello-femoral congruence angle as described by Merchant may be beyond the normal 16 degrees. CT or MRI scans have recently been demonstrated to be very effective in the demonstration of patello-femoral subluxation. Scanning has the advntage in that it can be performed in with the knee in full extension 10, 20 and 30 degrees of knee flexion when minor degrees of patello-femoral subluxation may be demonstrated, whereas these minor degrees of subluxation may not be apparent on the sky line view taken at 30 degrees of knee flexion.

    Patello-femoral subluxation or dislocation may be associated with damage to the medial facet of the patella or even chondral or osteochondral fractures.

    CHONDROMALACIA PATELLAE

    Chondromalacia, like anterior knee pain, is not a syndrome. Chondromalacia is the pathological appearance of fragmentation of the articular surface of the patella. The condition is usually associated with knee pain, chondromalacia has been reported as being present in 60% of normal adolescent children. One must also remember that the articular cartilage is insensitivie. If the articular cartilage fails to distribute the load, excessive force is then transmitted to the subchondral bone plate, deformation of the bone occurs which is interpreted by the feeling of pain. It must be remembered that the frons of cartilage seen are not the cause of pain but are produced by excessive stress. Removal of any functional articular cartilage whilst removing loose fronds of articular cartilage is detrimental as additional stree will be bourne by the subchondreal bone plate producing more not less pain.

    If the chondromalacia is of Grade 3 or 4, in which full thickness damage has occurred to the articular cartilage, then debridement of the loose articular cartilage may reveal the subchondral plate. In such circumstances, abrasion chondroplasty or drilling of the subchondral bone plate may be undertaken in an attempt to allow the ingress of fibrous tissue to cover the exposed bone. However as one might expect, the fibrous tissue which coveres the defect will only partially replace the function of the articular cartilage. The resistance of the fibrous scar to abrasion will be limited.

    Chondromalacia may be secondary to lateral hyperpressure or patello-femoral subluxation when it is limited to the lateral facet. Medial facet chondromalacia may be associated with episodes of patello-femoral dislocation. In this way, chondromalacia may be secondary to other pathological conditions and treatment of the primary cause may alleviate the problem. Idiopathic chondromalacia also exists in which the patella may generally be affected. In ideiopathic or generalised chondromalacia the treatment is much more difficult. A reduction in patello-femoral contact force may be produced by a Maquet type osteotomy advancing the tibial tuberosity forwards. This reduces the patello-femoral contact force but may be associated with a reduction in patello-femoral contact area and therefore not relieve the patello-femoral pain. At best improvement is only in 50% of patients, whilst the deformity and scar is commonly disfiguring.

    Chronic patello-femoral dislocation may be congenital or acquired. The acquired condition is usually associated with intra muscular injections into the quadriceps muscle during the neonatal period. A progressive fibrosis of the quadriceps muscle occurs which eventually produces recurrent, then habitual and finally chronic patello-femoral dislocation.

    OSTEOCHONDRITIS DISSECANS

    Osteochondritis dissecans was first described by Andrew Parry who removed a loose body in 1558. Paget described quiet necrosis of the knee in 1870 although Conning first described osteochondritis in 1888. Osteochondritis may present as anterior knee pain, recurrent swelling, locking or giving way. The most common site is on the lateral aspect of the intercondylar region of the medial femoral condyle. The lateral femoral condyle or patella may also be affeced. The arthroscopic treatment of osteochondritis was reviewed by Gull in 1985. Arthroscpic fixation of a loose osteochondral fragment of the patella may require knee arthrotomy . If the fragment of bone has become detached or fragmented and replacement with fixation is innaproppriate, debridement of the defect may be undertaken arthroscopically. /SYNOVIAL PLICAE/ Recently the importance of synovial plica in the production of anerior knee pain has been recognised. Plicae may cause pseudolocking and may even mimic acute internal derangement of the knee (Hughston at al. 1963, Pipkin 1971). The presentation of the syndrome may be delayed until symptoms are precipitated by inflammation within the plica secondary to an injury or a diminution in the elasticity of the plica which occurs with age. The symptoms are due to the plica bowstringing across the femoral condyle on knee flexion (Patel 1986).

    Plicae represent the remnants of the three separate synovial cavities present in the synovial mesenchyme of the developing knee which coalesce into one cavity at the 12 week stage of foetal growth (Gray and Gardner 1950). If the reabsorption of the divisions between the superior, the medial and the lateral cavities is incomplete then a medial supra-patellar plica, a lateral supra-patellar plica, or alternatively a supra-patellar membrane may result depending on the degree of reabsorption (Fig 1, Fig 2, Fig 3). A supra-patellar membrane may be complete such that a separate supra-patellar pouch exists which does not communicate with the knee joint (Fig 3). The membrane may be incomplete with an opening or `porta` from the supra-patellar pouch into the knee joint proper. Incomplete reabsorption elsewhere in the knee may result in the medial or lateral shelf or the anterior plica (Ogata and Uhthoff 1990) (Fig 1, Fig 2).

    Synovial plicae of the knee were first described in anatomic dissections by Fullerton in 1916, and by Mayeda in 1918 (Fullerton 1916, Mayeda 1918). The plicae were variously named ligamentum alaria, plica alaria, ligamentum mucosa, medio-patellar plica or a lateral alar fold. The arthroscopic appearances were first described by Iino, in 1939, and subsequently by Patel and Watanabe. He classified their appearances into four types (Iino 1939, Patel 1978, Watanabe, Takeda and Ikeuchi 1979). The medial and lateral bands along the upper border of the patella in a horizontal plane are the supero-medial plica or supero-lateral plica, or a supra patellar membrane (Fig 3). The plicae to the medial and lateral side of the patella running from the fat pad to the side of the patellar retinaculum in the coronal plane are the medial or lateral synovial shelf (Fig 2). The fold running from the fat pad to the intercondylar notch of the femur overlying the anterior cruciate ligament is called the anterior plica and is the most common plica in the knee (Fig 1, Fig 2). The medial shelf is the next most frequently encountered plica, the lateral shelf being less common. A complete supra-patellar membrane has been reported to be present in 2% of knees, incomplete membranes being more common (Johnson 1981). The plica syndrome has been reported in siblings (Reid et al. 1980).

    Post-mortem studies have shown plicae to occur in 20 – 50% of normal people (Hardaker, Whipple and Basset 1980, Wilhelm 1983, Zanoli and Piazzai 1983), with the highest incidence in people of Japanese descent (Mayeda 1918, Iino 1939, Aoki 1965, Sakakibara 1976, Jackson, Marshall and Fujisawa 1982). A 40 – 80% incidence of synovial plicae in arthroscopic examinations has been reported (Mizumachi, Kawaiashima and Okamura 1948, Broukhim et al. 1979, San Dretto et al. 1982, Johnson 1981, Dandy 1986).

    There is some controversy as to the prevalance of the plica syndrome and some reports even suggest that the pathological synovial plica does not exist, the plicae being a normal vestigial finding present in up to 60% of normal knees (Jackson 1980, Dandy 1981, Dandy 1986). Jackson, Dandy and others believe that plicae may be pathological but that overdiagnosis of the syndrome occurs, and many normal synovial shelves are removed (Jackson 1980, Hardaker, Whipple and Bassett 1980, Jackson, Marshall and Fujisawa 1982, Apple 1983, Zanoli and Piazzai 1983, Dupont 1985, Broom and Fulkerson 1986, Dandy 1986, Patel 1986, Lupi et al. 1990). Dandy considered only 1% of synovial plicae to be associated with a symptomatic medial shelf syndrome, and that the other plicae are not pathological (Dandy 1986). Conversely other authors consider the plica syndrome to be a common cause of anterior knee pain and often mis-diagnosed. It has been claimed that the supra-patellar membrane is virtually never asymptomatic (Nottage et al. 1983, Fujisawa, Jackson and Marshall 1976, Johnson 1981).

    Attempts have been made to quantify the occurrence of pathological plicae by analysing the histological findings of arthroscopic plical biopsies. Wilhelm reported histological findings of fibrosis indicative of chronic inflammation in 15% of a series of 186 medial shelf biopsies (Wilhelm 1983). Whilst Mital reported plical haemorrhage in 9 of 16 biopsies (Mital and Hayden 1979).

    Sherman described a set of criteria for the diagnosis of pathological synovial plicae. The criteria consisted of: 1- a history of the appropriate clinical symptoms, 2- the failure of conservative treatment, 3- the arthroscopic findings of a plica with an avascular fibrotic edge which impinged on the medial femoral condyle during knee flexion, 4- no other knee pathology which would explain the symptoms (Sherman and Jackson 1989). However Jackson commented that the severity of symptoms is not proportional to the size or breadth of the synovial plica (Jackson, Marshall and Fujisawa 1982), and Richmond found no correlation between the duration of symptoms and the presence of pathological changes in the plica (Richmond and McGinty 1983). It has been suggested that an impingement lesion, which is a localised area of chondromalacia at the site of femoral condyle impingement is evidence that a plica is pathological.

    Detection of synovial plicae as the cause of anterior knee pain is dependant on recognition of the relevant clinical symptoms and the absence of signs except perhaps for a palpable tender synovial band. Plicae are not well seen on plain radiographs, but a double contrast arthrogram may demonstrate the supra-patellar membrane and a synovial shelf. Double contrast arthrography may demonstrate a supra-patellar plicae in 20% of cases (Pipkin 1950, Apple et al. 1982, San Dretto et al. 1982, Aprin, Shapiro and Gershwind 1984, Lupi et al. 1990). The arthrographic appearances of the anterior plicae are often mistaken for the anterior cruciate ligament (Brody et al. 1983). A synovial shelf is more difficult to demonstrate by arthrography but the skyline view may demonstrate the synovial shelf (Deutsch et al. 1981, De la Caffiniere, Thijn and Hillen 1984).

    Ultrasonography has been reported as having a sensitivity of 92% and a specificity of 73% in the detection of plicae (Derks, de Hooge and Van Linge 1986). A radio-isotope technetium bone scan may show some focal increased uptake in association with an impingement lesion on the femoral condyle, but is otherwise normal (Brill 1984, Dye and Bell 1986). Computerised axial tomography (CT) has proven useful in the visualisation of the supra-patellar membrane but the synovial shelf is easily missed (Boven, De Boeck and Potvliege 1983, Schutzer, Ramsey and Fulherson 1986). The axial images of a Magnetic Resonance Scan (MRI) has in one study, proven to be a more useful mode of investigation than a CT Scan for the detection of synovial plicae and chondromalacia (Passariello et al. 1986). Radiographic and other modalities of investigation may be helpful in the clinical situation where the diagnosis is in doubt but are not routinely used in the detection of the plica syndrome which remains a clinical diagnosis confirmed during arthroscopy.

    The results of the treatment of anterior knee pain are notoriously difficult to assess objectively, primarily because a wide variety of conditions are usually gathered together under the category of anterior knee pain or chondromalacia patella (De Haven, Dolon and Mager 1979). In addition little account is taken of the reported natural improvement in the symptoms of anterior knee pain with time (Goodfellow, Hungerford and Woods 1976). Studies in this field must analyse the conditions included carefully and a randomised control group with long term assessment is necessary (Bentley and David 1984).

    The conservative treatment of the plica syndrome involves; quadriceps, hamstring and gastrocnemious stretching and isometric strengthening, cryotherapy, ultrasound, microwave diathermy, patellar bracing, bicycle riding, anti-inflammatory medication and an altered sports training schedule (Zanoli and Piazzai 1983, Newell and Bramwell 1984, Fisher 1986, Subotnick and Sisney 1986, Amatuzzi, Fazzi and Varella 1990). The results of such treatments in an uncontrolled study were an improvement in 40% of cases over a one year period (Rovere and Nichols 1985). Conversely Aprin suggested that, in knees in which an arthrogram demonstrated impingement of the plica on the femoral condyle in flexion, conservative treatment resulted in no long term improvement (Aprin, Shapiro and Gershwind 1984).

    Injection of the synovial plicae with steroid and local anaesthetic in another uncontrolled study gave excellent results in 73% of patients (Rovere and Adair 1985), although percutaneous injection of the thin intra-articular band of the plicae must be difficult and reliable placement impossible.

    Unfortunately all the studies on the surgical treatment of the plica syndrome are uncontrolled, non-randomised and often include a variety of pathologies (Patel 1978). Open knee arthrotomy and excision of the plica was first reported by Hughston (Hughston, Andrews and Waddell 1973) but has subsequently been reported by other authors (Patel 1978, De la Caffiniere, Mignot and Bruch 1981, Moller 1981). Arthrotomy has been superseded by the arthroscopic treatment of plicae which has been associated with good results in 60 – 90% of cases (Mital and Hayden 1979, Watanabe, Takeda and Ikeuchi 1979, Jackson, Marshall and Fujisawa 1982, Vaughan-Lane and Dandy 1982, Richmond and McGinty 1983, Zanoli and Piazzai 1983, Kinnard and Levesque1984, Bough and Regan 1985, Koshino and Okamoto 1985, Broom and Fulkerson 1986, O`Dwyer and Peace 1988, Sherman and Jackson 1989). Arthroscopic plical excision has also been demonstrated to reduce the magnitude of the knee audiogram (Johnson 1981).

    Chondromalacia patellae is commonly found in association with synovial plicae (O`Dwyer and Peace 1988). This is thought to be an association of two separate conditions in the same population (Patel 1978, Hansen and Boe 1989). Some studies have demonstrated inferior results following arthroscopic plica surgery when other pathologies such as chondromalacia patellae or patello-femoral subluxation are simultaneously present in the knee (De la Caffiniere, Mignot and Bruch 1981, Vaughan-Lane and Dandy 1982, Richmond and McGinty 1988, O`Dwyer and Peace 1988, Sherman and Jackson 1989). The overlap between the plica syndrome, lateral retinacular pain and lateral facet hyper-pressure syndrome is indistinct (Larson et al. 1978, Schulitz, Hille and Kochs 1983) and the conditions may co-exist. The situation following surgery may be further confused by a lateral release performed for lateral retinacular pain or the lateral hyper-pressure syndrome which may also divide any plicae present (Merchant and Mercer 1974, Larson et al. 1978, McGinty and McCarthy 1981).

    The main complication reported following arthroscopic surgery for synovial plicae is recurrence of symptoms in 5% of cases (Richmond and McGinty 1983). This may result from reformation of the synovial band following simple incision of the plicae, or scar formation around the base of the excised plicae (Dandy 1981, Anderson and Poulson 1986). A case of lateral patella subluxation has been reported following over-zealous resection of a medial shelf and the medial retinacular structures (Limbird 1988).

    As yet there has been no scientific study which shows synovial plicae to be pathological or that division of the plicae is of any benefit to the patient as compared to the natural improvement in adolescent anterior knee pain which occurs with the passage of time. The aims of this study were to determine if the synovial plicae of the knee is a pathological entity rather than a normal variant, and to determine whether arthroscopic division has any short or long term patient benefit when compared to a randomised control group.

    PATELLO – FEMORAL ARTHRITIS

    Patello-femoral arthritis may be secondary to trauma, lateral hyperpressure, lateral patello-femoral subluxation, patello-femoral dislocation or osteochondritis dissecans of he patella. Posterior cruciate instability produces excessive load in the patello-femoral joint and may be associated with early degenerative change. Fixed flexion deformity of the knee or hip may also cause premature changes in the patello-femoral joint due to excessive patello-femoral contact force.

    Primary osteoarthritis of the patello-femoral joint may be particularly prevalent in crystal arthropathy of pseudo gout or the hyperrophic variety of osteoarthritis. In both these conditions the patello-femoral joint may be affected by a flacid arthritis whilst the tibio-femoral joint is well preserved.

    THE CONSERVATIVE TREATMENT OF ANTERIOR KNEE PAIN

    The conservative treatment of anterior knee pain must initially consider the extraneous causes. The running or playing surface may need changing at least temporarily such that jogging or running can be performed on grass or a soft surface rather than pavements or concrete. The shoe wear may be changed with specialised shoes used for activities such as road running. Additional custom made orthoses may be necessary to correct excessive foot pronation, metatarsalgia, hallux rigidus, calcaneal varus or valgus, equinus, femoral anteversion or external tibial torsion. / Physiotherapy should be directed towards flexibility, posture, muscular strengthening and the alaeviation of inflammation. Objective isokinetic muscular assessment may be undertaken using a Kin-Com, Cybex or other similar computerised dynamometer. In these machines the muscle strength is tested throughout the range of motion and a graphic record of muscle function is produced. This graphic record may be compared to the results from the opposite side or with the results from the same side at different times during the rehabilitation. The muscular balance between the quadriceps and hamstrings muscles and between the concentric and eccentric modes of muscular contraction may be compared and rehabilitation specifically concentrated on the observed areas of weakness.

    In the discussion of this modality it is important to understand the terms used. Isometric exercises are undertaken with the maintenance of muscular contraction at a constant low length with variable lows. Isotonic activity is undertaken using muscular contraction against a constant load varying the speed and the length of the muscles. Isokinetic activity is undertaken with muscular contraction undertaken at a constant angular velocity. The load and length of the muscle are varied. Concentric muscular contraction is undertaken where shortening of the muscle length occurs against loads. Eccentric contraction is where the muscle lengthens against a load. A recent study demonstrates that the eccentric mode of isokinetic activity may be the most sensitive in diagnostic evauluation and also in muscular retraining.

    When analysising the various patterns of activity, the phased hamstring eccentric isokinetic analysis undertaken with an angular velocity of 180 degrees per second, reveals a deficit in function particularly associated with loose bodies, torn lateral meniscus and osteochondral defects. Whereas synovial plicae characteristically causes a reduction in the peak torque generated between 40 and 80 degrees of flexion during eccentric quadriceps activity at 60 degrees per second, the investigation may also be used to assess the results of surgery in that the pattern of activity my be restored to normal after excision of a synovial plica or other pathology.

    The continual assessment is also useful during a rehabilitation phase to analyse the return of muscular strength and to determine when return to full activity is possible. This has been extensively used in association with the rehabilitation of anterior cruciate surgery whereby return to full sporting activities is usually allowed only after the attainment of 90% of the muscular strength of the normal side.

    Other mechanical and electrical modalities of physiotheraph such as cryotherapy, ultrasound and mega-pulse electro-therapy may be used when soft tissue inflammation is present. Patello-femoral bracing or tapeing to stabilise the patello-femoral joint or to correct lateral maltracking may relieve the pain from lateral patella tracking or patella subluxation. McConnell, an Australian physiotherapist, described a complete programme of patello-femoral rehabilitation which included retraining and strengthening the vastus medialis muscle using bio-feedback to promote vastus medialis action early in the phase of knee flexion. / Such conservative therapy may be supplemented by non steroidal anti inflammatory medication as necessary, a steroid injection into extra-articular soft tissues and non weight bearing tendons may be of benefit. Injection into weight bearing tendons such as the achilles tendon should be discouraged as reupture may be precipitated. Repeated intra-articular injections have been reported to result in damage to the articular cartilage and should be avoided. Temporary periods of rest may also alleviate the symptoms.

    There are studies which suggest that conservative treatment in anterior knee pain may result in an initial improvement in up to 87% of patients. However this diminishes to 60% on follow up at three months. A study by Goodfellow et al demonstrated that, in a cohort of femalepatients with anterior knee pain, 49% of patients improved following an average 16 month duration of conservative therapy. However it was also noted that 96% of patients retain some anterior knee pain at final follow up.

    In a recent study undertaken by the author in patients with synovial plica syndrome, improvement occurred in only 28% of patients over a two year period treated by diagnostic arthroscopy and conservative measures. This compares with a 96% improvement following surgical division of the synovial plica. Thus the expected improvement in the symptoms of anterior knee pain with time may be sustained by hope and fustration rather than any objective evidence.

    THE SURGICAL TREATMENT OF ANTERIOR KNEE PAIN

    The surgical treatment of anterior knee pain may include excision of the degenerative area within the patellar tendon in patellar tendonitis. The central portion of the patellar tendon may be released from the inferior pole of the patella although this may be unnecessary and may reduce the strength of the patellar tendon. Peri-patellar bursitis may be treated by aspiration, injection or excision if necessary. Arthroscopic surgery may be undertaken to: remove anterior meniscal tears, remove meniscal cysts, to decompress meniscal cysts, to remove loose bodies in the front of the knee and to debride areas of osteochondritis dissecans.

    Cruciate ligament reconstruction may alleviate the anterior knee pain associated with these conditions. However, any retro-patellar articular degeneration may not be reversible. As already stated following anterior cruciate ligament reconstruction using the central third of the patellar tendon, an instance of 20% of anterior knee pain has been noted. Atension to detail during surgery may reduce this incidence. Arthroscopy and arthroscopic excision of the fat pad may be undertaken in Hoffa’s syndrome where the hypertrophic fat pad or infra-patellar xanthoma may be removed. The condition of peri-patella pannus formation or quadriceps fibrosis where an excessive fibrous reaction occurs in the synovium around the patella. The hypertrophic synovium encroaches into the patello-femoral joint causing impingement and pain. Local synovectomymay be of benefit. In similar way, synovial tumours such as lipoma, pedunculated fibromas intra-articular xanthomas and areas of pigmented villo-nodular synovitis may arthroscopically excised. It may also be possible to remove benign bony tumours arround the knee such as a solitary enchondroma arthroscopically. / In the condition of lateral patellar hyper-pressure syndrome, lateral patellar tilt and lateral patello-femoral facet chondromlacia, lateral retinacular pain, lateral retinacular nerve injury or patello-femoral subluxation arthroscopic lateral retinacular release may give symptomatic relief.

    PATELLO-FEMORAL SUBLUXATION

    Minor degrees of patello-femoral subluxation without dislocation, may be relieved by arthroscopic lateral release although there is a described incidence of recurrence. Risk factors include multiple ligamentous laxity, paella alta, hyperplastic femoral condyle, increased ‘Q’ angle, external tibial torsion, persistent femoral anteversion or an avulsed and ruptured vastus medialis. In athletes having sustained a single dislocation of the patello-femoral joint, I prefer to undertake early arthroscopy, drainage of the haematoma, debridement of any articular damage and arthroscopic lateral release followed by early rehabilitation including quadriceps strengthening exercises. Empricle lateral release for anterior knee pain is undertaken in some centres but must be strongly discouraged as inappropriate lateral release may produce medial patella dislocation and other problems. / In patients with recurrent patello-femoral subluxation, as an initial procedure I use arthroscopic lateral release in isolation unless multiple ligamentous laxity or other gross deformity is present. In the presence of risk factors or multiple ligamentous laxity, I prefer to combine arthroscopic lateral release with repair of the vastus medialis and transposition of the vastus medialis to the anterior medial surface of the patella. I combine this with an extra-articular modified Elmsley-Trillat procedure in which the tibial tuberosity is elevated on a distal base rotated medially and fixed with a single screw. In many instances, if fixation is adequate, early rehabilitation can be undertaken without the need for an immobilisation in a plaster cast or splint. Discharge from hospital is present after one or two nights and early return to full activity after only 6 weeks may be expected. I find that this procedure leaves only two 2 cm long scars at the superior medial border of the patella and to the lateral side of the tibial tuberosity. There is minimal inhibition of the quadriceps muscle and no ugly deformity or scarring of the knee results.

    CHONDROMALACIA

    Arthroscopic surgery for chondromalacia or articular cartilage defects in the patello-femoral joint is difficult and the results of such treatment are not well defined. Generally loose articular fonds and fragments may be removed. Any articular cartilage adherent to the subchondral bone may be assumed to be functional and should not be removed only to improve the visual appearances. Abrasion chondroplasty or articular drilling with a 1mm drill are the techniques for abrading the exposed subchondral bone in the base of articular defects in order to promote the ingress of fibrous tissue. This tissue may cover the exposed bone and provide a new articular surface composed of fibrous scar tissue. This may in some cases relieve for a time the pain experienced. The fibrous tissue is never as good as articular cartilage and therefore excision of the lose articular fragments and fronds should be kept to a minimum. It is suggested in the literature that the maximum area of exposed bone which may be helped by an abrasion chondroplasty may be as small as 1 cm in diameter.

    Chondromalacia of the femoral trochlear groove presents a difficult problem. This situation is commonly found in association with netball, basketball and Australian Rules football which require jumping. Abrasion chondroplasty is usually undertaken.

    Arthroscopic surgery for chondromalacia in other sites should also be directed to the primary cause if one is present. If the chondromalacia is secondary to lateral hyper-pressure, lateral patello-femoral subluxation or dislocation, then this is treated while the chondromalacia is merely debrided. In the presence of chondromalacia of the central ridge or generalised over the whole patella there is usually no definable cause treatable by arthroscopy. Generalised patella chondromalacia or chondromalacia on the central ridge may be resistant to all other measures. In this situation subsequently a Macquet type advancement of the tibial tuberosity may be undertaken in mature patients. This should only be undertaken after due consultation in view of the ugly scar, the resulting deformity of the knee and the expected success in only 50% of patients.

    PATELLECTOMY

    I avoid patellectomy if at all possible despite persistent anterior knee pain. There is persistent weakness of the quadriceps muscle estimated at 30% which results in poor function, and in addition, excessive compressive forces are transmitted to the tibio femoral joint and acceleration of any degenerative change in the knee joint occurs. Although total knee replacement in the absence of a patella is technically possible the resulting function is poor. It has been my experience that patellectomy is also associated with persistent knee pain, the formation of bone fragments beneath the patellar tendon which may cause persistent anterior knee pain. On three occasions I have undertaken late debridement and lateral release of the repaired quadriceps/patellar tendon because of anterior knee pain, lateral retinacular pain, lateral tendon subluxation and restricted knee flexion.

    Though I believe that conservative therapy for anterior knee pain is sufficient in approximately 50% of patients, of those remaining I believe that a clinical definable pathology is present in perhaps 80% to 90% of patients. Of these patients, 80% may be amenable to surgical therapy. There does, however, remain a proportion of patients complaining of anterior knee pain in which no definable pathological cause may be found. In these cases, reflex sympathetic dystrophy must be considered, although the treatment of reflex sympathetic dystrophy is difficult.

    CONCLUSION

    The management of anterior knee pain demands an understanding of the numerous pathological entities which may cause it. A careful relevant history and examination is necessary. If properly organised conservative treatment is unsuccessful a variety of surgical procedures are available. Successful treatment may be possible in up to 90% of patients, whereas without proper treatment there is little evidence that the symptoms will settle and in some cases patello-femoral arthritis may be avoidable. The attitude that anterior knee pain is a self limiting condition in patients with underlying neurotic personalities should be condemned to the archives of orthopaedic surgery.

  7. Partial Rupture of the Anterior Cruciate Ligament

    Partial Rupture of the Anterior Cruciate Ligament 

    D P Johnson and O Basso

    There is confusion regarding the diagnosis and clinical outcome following partial rupture of the anterior cruciate ligament. The diagnosis is often made when there is a moderate degree of instability or when the arthroscopic appearances of the cruciate do not demonstrate complete rupture. There is conflicting opinion as to whether this injury results in chronic instability, increasing laxity and degenerative change as has now been demonstrated in complete anterior cruciate ligament. No previous attempt has been made to clarify the diagnosis and assess the clinical outcome of this injury.

    This study analysed prospectively 26 cases followed for a mean duration of 2 years in which the diagnosis was made following clinical examination, plain radiography, MRI and arthroscopic assessment by a single surgeon. Clinical criteria for the diagnosis included a negative pivot shift, a positive anterior draw or Lachmans test and a partial rupture or laxity of the anterior cruciate ligament at arthroscopy. Patients were assessed at final follow up by clinical examination by the same surgeon, KT 1000 arthrometry, plain radiography and isokinetic dynamometry. The radiographs were analysed independently by two blinded radiographers for the extent of the ligament rupture. The results were submitted to statistical analysis.

    The results demonstrated that the experienced knee MRI radiographers were unable to differentiate a partial rupture from a complete rupture (p<0.01). Two of the 26 patients had persistent instability and undergone successful anterior cruciate reconstruction. In both of these patients it was noted at the initial arthroscopy that less than 50% of the ligament remained (p<0.01). In the other 24 patients in which more than 50% of the ligament was intact at the initial arthroscopy no further episodes of instability occurred and none required further surgical intervention. After two year follow up none were limited by their knee in sporting activities, there was no increased laxity in the knees on clinical examination or on KT 1000 testing. Isokinetic analysis demonstrated a mean 13% reduction in quadriceps strength in the affected knee.

    This study demonstrates that following partial rupture of the anterior cruciate ligament in which the pivot shift is negative. MRI is unable to differentiate the partially torn ACL from the completely torn ligament. If greater than 50% of the ligament is intact there is no increased laxity or functional restriction over a 2 year period and these patients should undergo an intensive period of rehabilitation rather than surgical reconstruction.

  8. Radiological and M.R.I. Analysis of the Morphology of Patellar Tendonitis

    Radiological and M.R.I. Analysis of the Morphology of Patellar Tendonitis 

    Mr D P Johnson, Dr I Watt and Dr C Wakeley 

    Patellar tendonitis is thought to be due to a chronic overload of the tendon which results in repetitive microscopic damage and inflammation within the upper central aspect of the patellar tendon resulting in histological focal degeneration. This study was performed to analyse the morphology of the patella in this condition by conventional radiology and by MRI.

    The analysis consisted of 22 patients presenting with chronic severe (Grade 2,3, or 4) patellar tendonitis. Patients were assessed clinically and radiologically in flexion and extension. The radiographs were analysed to determine the morphology of the inferior pole of the patellar and the spatial relationship during flexion. Various MRI imaging modalities were obtained in the position of knee flexion and extension. The imaging modalities were analysed to determine the optimal method. The results were then compared to a matched control group of patients.

    The results demonstrated that there was no significant difference in the morphology of the patella in terms of patello-femoral tilt, congruence angle, or patella index. The inferior pole of the patella did not prove to be significantly elongated in the affected patients. There was a significant increase in the length of the patellar tendon in affected individuals. The MRI appearances demonstrated the inflammation characteristically in the deep superior and central part of the tendon. The appearances were most apparent on the saggital T2 sequences. There was also a significant increase in the thickness of the upper patellar tendon as compared to the control group. It was apparent that the majority of the patellar tendon did not insert into the inferior pole of the patella but continues over the anterior cortex. Thus in the position of knee flexion the inferior pole was seen to impinge on the characteristically inflamed region of the tendon.

    This study has characterised and categorised the morphology, radiology and MRI appearances in this condition. The results suggest that the micro-trauma and degeneration may be a result of impingement against the inferior pole in flexion rather than the tensile failure. This newly described pathogenesis would correlate with and be supported by the effectiveness of surgical release of the central portion of the tendon.

  9. Arthroscopic Surgery for Patellar Tendonitis: A One to Four Year Follow Up Study

    Arthroscopic Surgery for Patellar Tendonitis: A One to Four Year Follow Up Study

    D P Johnson 

    The histological appearances of patellar tendonitis were reported by Martens in 1982, and assumed to represent a micro fracture or a partial rupture of the tendon. Surgical techniques are sometimes required in the management and include detachment of the patella tendon from the inferior pole, excision of the degenerative nodule, drilling, or excision of the inferior pole, which are all reported to be successful in 60 – 90% of cases. In a previous study of the radiological and MRI appearances in this condition, a normal morphology of the patella, and an increased high signal intensity in the superior, central and posterior aspect of the tendon was noted. It was, proposed that a possible pathogenesis for this condition may in fact be an impingement or compression of the inferior pole of the patella onto the posterior aspect of the tendon in flexion. If correct, the surgical rational should be to release the deeper fibres of the tendon from the inferior pole and to surgically excise the tip. An inital study of 20 patients treated by arthroscopic decompression and marginal excision of the inferior pole was first presented 2 years ago. This study analysed the 1-4 year results in a larger population.

    We analysed a population of 35 patients with patella tendonitis resistant to conservative treatment undergoing release of the deep central aspect of the tendon and excision of the inferior pole undertaken as a wholy arthroscopic procedure with a 1-4 year follow up. The patients had significant grade III patella tendonitis. The technique included elevation and partial excision of the superior central part of the fat pad to reveal the bare area of the patella. Elevation of the patella tendon fibres from the anterior 5 millimetre surface of the inferior pole of the patella, and excision of the exposed inferior pole. Patients were mobilised and discharged as a day case in over 50 per cent of cases. The average operating time was 45 minutes. There was no instance of instrument breakage. No conversion to an open procedure or operative complications. There were no re-admissions for haemarthrosis. Final review revealed that 90% of patients had good or excellent results. One patient had a fair result, one had a poor result. Patients returned to work on average in 2 weeks, sport on average in 9 weeks, became symptom free in 10 weeks, and returned to competition on average in 13 weeks following surgery.

    We, therefore, concluded that decompression of the inferior pole of the patella by elevation of the central portion of the tendon from the inferior pole and excision of the inferior pole without specific excision of the degenerative lesion was successful in 90% of cases. It was technically feasible to undertake this as a day surgery arthroscopic procedure with rapid rehabilitation. We are currently analysing histological specimens from 8 cases of patellar tendonitis, but the previously reported appearances are compatable with a chronic repetative posterior impingement on the tendon. We have previously suggested a new patho-aetiology of patellar tendonitis; of a posterior impingement to the tendon and subsequent degeneration. The results of this study certainly support this aetiology of the condition. The condition is best investigated by MRI, surgical treament should be aimed at release of the deep fibres of the tendon from the patella and excision of the tip of the inferior pole. This can reliably, safely and successfully be undertaken as an arthroscopic day surgery procedure.

  10. Anatomy, Diagnosis Mechanics and Management of Anterior Knee Pain

    Anatomy, Diagnosis Mechcanics and Management of Anterior Knee Pain 

    D P Johnson
    1 Introduction

    Optimum knee function is of vital importance in daily activities and a wide variety of sports. Knee stability is also important especially in running, twisting, jumping and pivoting. Injuries to the knee are very common because of the lack of bony joint congruity and the reliance of the knee on muscular and ligamentous support. Knee injuries are the most common serious injury during sporting activities. 

    Pain experienced in the front of the knee is commonly described as Anterior Knee Pain. Anterior knee pain affects 29% of adolescent children (Fairbank 1984). This may be related to the increase in structured sporting activity which occurs at school during early adolescence. Anterior knee pain is particularly prevalent in certain sports which include basketball, netball, athletics, skiing and cycling. In these sports, activities are undertaken whilst the knee is in a flexed position, and or jumping is common. To understand the patho-mechanics of anterior knee pain, the anatomy, clinical examination and mechanics of the knee must be well understood. Much of the confusion surrounding anterior knee pain and its treatment has been produced by the inability of the practitioner to translate distinct clinical problems into a specific classification. This applies whether they be a general practitioner or hospital consultant.

    2 Functional Anatomy of the Patello-Femoral Joint

    The anatomy of the knee can be broadly divided into the three joints; the patello-femoral articulation, the medial and the lateral tibio-femoral joints. To understand the pathology of anterior knee pain this distinction is very important. The weight transfer across the tibio-femoral joint is aided by the menisci which distribute the compressive forces and reduce pressure on any particular point. The patello-femoral joint bears little load whilst standing with the knee in extension. The patello-femoral contact force is greatest between 30 and 70 degrees of knee flexion (Ficat et al). During flexion the site of contact on the patella changes. The area of contact of the patello-femoral joint increases during knee flexion. These mechanisms assist in dissipating the extra loading on the patello-femoral joint during flexion. Nonetheless when descending stairs, jumping or landing as in netball and basketball the compressive load across the patello-femoral joint may reach five times the weight of the body (Ficat et al). 

    The articular cartilage on the patella is up to 5 mm thick; thicker than anywhere else in the skeleton. Besides allowing unresisted motion the function of the articular cartilage is to help dissipate the compressive forces and prevent excessive loading on the subchondral bone plate. Such pressure is interpreted as pain. Generally it is the extreme forces experienced by the patello-femoral joint during sport that results in the high incidence of anterior knee pain in athletes.

    3 Pathomechanics of Anterior Knee Pain 

    The patella has a very important function in the mechanics of the knee. The patella increases the moment of action of the quadriceps expansion and increases the extensor force by a factor of two to threefold. In the absence of the patella, such as following a patellectomy, the strength of the quadriceps muscle is diminished by at least 30%, the tibio femoral compressive force is increased and degenerative change within the tibio-femoral joint is increased. 

    4 Anterior Knee Pain as a Symptom

    It is important to realise that anterior knee pain is a symptom and not a syndrome. It is insufficient for a clinician to make a diagnosis of anterior knee pain as many different causes have been identified. Whilst it is true that in almost all cases of anterior knee pain an initial period of quadriceps strengthening exercises, physiotherapy and non steroidal anti-inflammatory medication will be prescribed. A provisional pathological diagnosis as to the cause of the pain will give guidance to the physiotherapist, podiatrist, sports trainer and coach. A provisional diagnosis will enable the options for treatment to be discussed with the patient and therapists. The surgical options can be discussed for those cases which do not settle following the initial course of conservative treatment.

    To make a provisional diagnosis the clinician should accurately identify the activity which precipitates the pain, the character of the pain and the angle of knee flexion at which the pain is worst. Commonly patello-femoral pain is exacerbated by activities such as descending or ascending stairs, rising out of a chair or driving. These are the activities in which the patello-femoral compressive forces are highest. Any associated clicking, giving way or episodes of patello-femoral instability of the knee should be identified. The exact site of the pain in the front of the knee must be determined, whether it is in the supra-patellar pouch, medial or lateral retinaculum, retro-patellar, at the inferior pole of the patella, medial or lateral part of the fat pad, the anterior horn of the menisci or tibial tuberosity. Thus the history must be detailed and concentrated on the symptoms pertaining to the patello-femoral joint.

    5 Clinical Examination in Anterior Knee Pain

    Anterior knee pain in athletes may be caused by extraneous problems. In runners and athletes in general, analysis of shoe wear is important. Badly worn shoes or poorly designed shoes may produce excessive foot pronation and exacerbate any tendency to flat feet which may precipitate anterior knee pain. The running or playing surface may also be important, particularly when excessive road running is undertaken. In these cases the pain may be helped by running predominantly on grass rather than on roads. Podiatric advice may be helpful and, despite the reluctance of some clinicians to consider podiatry, it is usually easier, cheaper and painless when compared with operative surgery.

    Clinical examination should include examination of the feet, ankles, hips, spine and the contra-lateral knee for stiffness, pain or a clinical deformity. Common clinical pitfalls often missed above the knee are the painful stiff hip, trochanteric bursitis, lumbar stiffness, spondylolysthesis and tight hamstring muscles. Below the knee shin splints, stress fractures, ankle stiffness and flat feet may be related to anterior knee pain. Congenital multiple ligamentous laxity should also be specifically sought as it has a significant effect on the treatment of anterior knee pain.

    At the knee the usual examination should be undertaken to exclude meniscal or ligamentous injuries and early arthritis. The range of motion and alignment of the limb in terms of varus and valgus deformity at the knee must be determined. Special attention must be paid to palpate the anterior part of the menisci to exclude an anterior horn meniscal tear. This is best done with the knee in the position of flexion. One should also be aware that both anterior and posterior cruciate ligament injuries may present with anterior knee pain.

    Examination of the front of the knee necessarily needs to be detailed and accurate. Inspection may detect swelling as seen with pre-patellar bursitis or Osgood Schlatters disease in which the tibial tuberosity is swollen. An effusion indicates an intra-articular pathology. Palpation should start in the supra-patellar pouch and move down the patellar retinaculum either side of the patella into the fat pad which lies to either side of the patellar tendon. A tender synovial fold or “plica” may be palpated in this region around the patella. Examination should proceed with palpation of the tibial tuberosity followed by the patellar tendon and the inferior pole of the patella; the site of tenderness in patellar tendonitis.

    Examination of the patella should then be undertaken. The superficial surface is easy whilst the posterior surface may be palpated by displacing the patella to the medial side and palpating the exposed undersurface and repeating the manoeuvre to the lateral side. The patella should then be compressed against the femur as it is gently moved to the medial and lateral side and up and down. This manoeuvre may detect crepitus and roughness within the patello-femoral joint, pain may also be elicited. The patello-femoral joint should also be compressed as the knee is flexed. This may elicit crepitus and this test may also reproduce the pain experienced.

    If patello-femoral subluxation or dislocation is suspected, the apprehension test is performed in which the patella is displaced laterally whilst the knee is extended. Apprehension may be produced by the fear of an impending dislocation and the knee is involuntarily flexed to prevent the patella subluxing. This test is usually negative if dislocation has not previously occurred. If the excursion of the patella to the lateral side is restricted by a tight lateral patellar retinaculum, lateral patella hyperpressure syndrome may be suspected in which the tight lateral retinaculum tilts the patella laterally during flexion compressing the lateral side of the patello-femoral joint causing pain.

    6 Radiography of the Patello-Femoral Joint

    The plain antero-posterior and lateral films are not ideal for pathology suspected of being in the patello-femoral joint. Although the anterior-posterior view may demonstrate a bipartite patella in which the patella develops in two parts. The lateral view of the knee may demonstrate patella osteophytes although this is usually only at a fairly advanced stage of arthritis. The lateral view may show a patella alta (high patella) which is associated with patella subluxation and dislocation, or a patella baja (low patella) associated with retro patella pain and arthritis. Osgood-Schlatters disease in which partial separation of the tibial tuberosity apophysis, or Sinding Larsen Johansen’s disease at the inferior pole of the patella, may also be identified.

    The best radiograph for the demonstration of patello-femoral pathology is the skyline view taken in 30 degrees of knee flexion. This demonstrates subluxation, patella tilt, lateral patella hyperpressure and any arthritis or thinning of the articular cartilage. Further information may be obtained by repeating the skyline radiograph at 60 and 90 degrees of knee flexion. The concept of patello-femoral tilt was described by Lauren. He described the lateral patello-femoral angle as a measurement often used in the interpretation of radiographs. In the presence of patello-femoral tilt, this angle may be reduced as the patella tilts to the lateral side. It is important not to be confused as patello-femoral tilt may or may not exist with radiological subluxation in which the patella is displaced laterally.

    Arthoraphy is not now commonly used as scanning techniques reveal much more information. However arthoraphy does demonstrate synovial folds or plicae within the joint which are not well demonstrated by MRI scanning.

    Computerised Axial Scanning (CAT) of the patello-femoral joint has been superseded by Magnetic Resonance Imaging (MRI). MRI is the imaging technique which reveals most information in patello-femoral pathology. The relationship of the patella to the femoral trochlear is well shown. Any synovial folds or plicae in the patella retinaculum or fibrosis of the fat pad may be seen. Occasionally intra-articular tumours are demonstrated. Using sagittal or coronal sections, defects in the articular cartilage can be shown on the patella or femoral trochlear. Other conditions, particularly those associated with soft tissue inflammation such as patellar tendonitis, are clearly defined.

    Radio-isotope scanning of the knee is sometimes useful in demonstrating those parts of the knee which have an increased bone metabolism. In this way active and possibly symptomatic areas may be demonstrated.

    Reflex sympathetic dystrophy may affect the patella after a minor injury or surgery. This condition is difficult to diagnose but may result in chronic knee pain and stiffness of the knee. A radio-isotope bone scan demonstrates a characteristic increased uptake in the affected area.

    7 Classification of Anterior Knee Pain

    Patello-femoral disorders causing anterior knee pain were well classified by Merchant in 1988. The classification divides the causes of anterior knee pain into acute trauma, repetitive trauma, the late effects of trauma, patello-femoral dysplasia, idiopathic chondromalacia, osteochondritis dissecans, synovial plica and patello-femoral arthritis.

    8 Patello-Femoral Dysplasia

    The most difficult area of classification is dysplasia of the patello-femoral joint. Patello-femoral maltracking is a clinical sign which is exceedingly difficult to describe, quantify or classify. It is best seen while the knee is flexed while the examiner stands above the knee and looks down along the patello-femoral joint. In a normal situation the patella follows a straight course as the knee flexes. The patella moves down in to the femoral trochlear groove and into the intercondylar region. In lateral maltracking the patella may move laterally particularly in the first 20 to 30 degrees of knee flexion before then moving medially to enter the patello-femoral groove. The patella may or may not again move laterally beyond 70 degrees of knee flexion. This may be associated with an increased tibio-femoral ‘Q’ angle and external tibial torsion. Lateral patella tracking is associated with anterior knee pain and chondromalacia although the relationship has not been clearly identified.

    9 Lateral Patellar Hyperpressure

    As described this condition in which excessive tightness in the lateral retinaculum produces lateral tilt and excessive compression in the lateral facet of the patello-femoral joint. The sky line radiograph, taken at 30 degrees of knee flexion, may show lateral tilt of the patella onto the lateral facet. This condition is associated with, and possibly produces, chondromalacia patella on the lateral patella facet and eventually produces lateral facet osteoarthritis of the patello-femoral joint. This is one of the conditions in which lateral release of the patella may have good results and possibly prevent the progression to arthritis of the patello-femoral joint.

    10 Patello-Femoral Subluxation

    Patello-femoral subluxation may be obvious when the patient recounts episodes in which the patella partially dislocates prior to relocating in the patello-femoral joint. Alternatively, the knee may have a feeling of being weak or giving way particularly whilst descending stairs or during sporting activities. Clinical examination may reveal lateral subluxation or lateral patello-femoral tracking. Additional signs such as patella alta, hypoplastic lateral femoral condyle, increased femoral-tibial ‘Q’ angle, persistent femoral anteversion, external tibial torsion or multiple ligamentous laxity may be present. Clinical examination may reveal a positive apprehension test. Sky line radiographs taken at 30 degrees of knee flexion may demonstrate patello-femoral tilt or overhang. The sky line radiograph may demonstrate overhang of the lateral border of the patella beyond the lateral femoral condyles. The patello-femoral congruence angle as described by Merchant may be beyond the normal 16 degrees. CT or MRI scans have recently been demonstrated to be very effective in the demonstration of patello-femoral subluxation. Scanning has the advantage in that it can be performed with the knee in full extension or 10, 20 and 30 degrees of knee flexion when minor degrees of patello-femoral subluxation may be demonstrated, whereas these minor degrees of subluxation may not be apparent on the sky line view taken at 30 degrees of knee flexion.

    Patello-femoral subluxation or dislocation may be associated with damage to the medial facet of the patella or even chondral or osteochondral fractures.

    11 Chondromalacia PatellaeChondromalacia

    Like anterior knee pain, Chondromalacia is not a syndrome. Chondromalacia is the pathological appearance of fragmentation of the articular surface of the patella. The condition is usually associated with knee pain and chondromalacia has been reported as being present in 60% of normal adolescent children. One must also remember that the articular cartilage is insensitive. If the articular cartilage fails to distribute the load, excessive force is then transmitted to the subchondral bone plate, deformation of the bone occurs which is interpreted by the feeling of pain. It must be remembered that the fronds of cartilage seen are not the cause of pain but are produced by excessive stress. Removal of any functional articular cartilage whilst removing loose fronds of articular cartilage is detrimental as additional stress will be borne by the subchondral bone plate producing more not less pain.

    If the chondromalacia is of Grade 3 or 4, in which full thickness damage has occurred to the articular cartilage, then debridement of the loose articular cartilage may reveal the subchondral plate. In such circumstances, abrasion chondroplasty or drilling of the subchondral bone plate may be undertaken in an attempt to allow the ingress of fibrous tissue to cover the exposed bone. However, as one might expect, the fibrous tissue which covers the defect will only partially replace the function of the articular cartilage. The resistance of the fibrous scar to abrasion will be limited.

    Chondromalacia may be secondary to lateral hyperpressure or patello-femoral subluxation when it is limited to the lateral facet. Medial facet chondromalacia may be associated with episodes of patello-femoral dislocation. In this way, chondromalacia may be secondary to other pathological conditions and treatment of the primary cause may alleviate the problem. Idiopathic chondromalacia also exists in which the patella may generally be affected. In idiopathic or generalised chondromalacia the treatment is much more difficult. A reduction in patello-femoral contact force may be produced by a Maquet type osteotomy advancing the tibial tuberosity forwards. This reduces the patello-femoral contact force but may be associated with a reduction in patello-femoral contact area and therefore not relieve the patello-femoral pain. At best improvement is only in 50% of patients, whilst the deformity and scar is commonly disfiguring.

    Chronic patello-femoral dislocation may be congenital or acquired. The acquired condition is usually associated with intra muscular injections into the quadriceps muscle during the neonatal period. A progressive fibrosis of the quadriceps muscle occurs which eventually produces recurrent, then habitual and finally chronic patello-femoral dislocation.

    12 Osteochondritis Dissecans

    Osteochondritis dissecans was first described by Andrew Parry who removed a loose body in 1558. Paget described quiet necrosis of the knee in 1870 although Conning first described osteochondritis in 1888. Osteochondritis may present as anterior knee pain, recurrent swelling, locking or giving way. The most common site is on the lateral aspect of the intercondylar region of the medial femoral condyle. The lateral femoral condyle or patella may also be affected. The arthroscopic treatment of osteochondritis was reviewed by Gull in 1985. Arthroscopic fixation of a loose osteochondral fragment of the patella may require knee arthrotomy. If the fragment of bone has become detached or fragmented and replacement with fixation is inappropriate, debridement of the defect may be undertaken arthroscopically. 

    13 Synovial Plicae

    Recently the important of synovial plicae in the production of anterior knee pain has been recognised (Johnson et al 1984). Plicae may cuase pseudolocking and may even mimic acute internal derangement of the knee (Hughston et al 1963, Pipkin 1971). The presentation of the syndrome may be delayed until symptoms are precipitated by inflammation within the plica secondary to an injury or a diminution in the elasticity of the plica which occurs with age. The symptoms are due to the plica bowstringing, across, or clicking over the femoral condyle on knee flexion (Patel 1986).

    Plicae represent the remnants of the three separate synovial cavities present in the synovial mesenchyme of the developing knee which coalesce into one cavity at the 12 week stage of foetal growth (Gray and Gardner 1950). If the reabsorption of the divisions between the superior, the medial and the lateral cavities is incomplete then a medial supra-patellar plica, a lateral supra-patellar plica, or alternatively, a supra-patellar membrane may result depending on the degree of reabsorption . A supra-patellar membrane may be complete such that a separate supra-patellar pouch exists which does not communicate with the knee joint. The membrane may be incomplete with an opening or ‘porta’ from the supra-patellar pouch into the knee joint proper. Incomplete reabsorption elsewhere in the knee may result in the medial or lateral shelf or the anterior plica (Ogata and Uhthoff 1990).

    Synovial plicae of the knee were first described in anatomic dissections by Fullerton in 1916, and by Mayeda in 1918 (Fullerton 1916, Mayeda 1918). The plicae were variously named ligamentum alaria, plica alaria, ligamentum mucosa, medio-patellar plica or a lateral alar fold. The arthroscopic appearances were first described by Lino, in 1939, and subsequently by Patel and Watanabe. He classified their appearances into four types (Lino 1939, Patel 1978, Watanable, Takeda and Ikeuchi 1979). The medial and lateral bands along the upper border of the patella in a horizontal plane are the supero-medial plica or supero-lateral plica, or a supra patellar membrane. The plicae to the medial and lateral side of the patella running from the fat pad to the side of the patellar retinaculum in the coronal plane are the medial or lateral synovial shelf . The fold running from the fat pad to the intercondylar notch of the femur overlying the anterior cruciate ligament is called the anterior plica and is the most common plica in the knee. The medial shelf is the next most frequently encountered plica, the lateral shelf being less common. A complete supra-patellar membrane has been reported to be present in 2% of knees, incomplete membranes being more common (Johnson 1981). The plica syndrome has been reported in siblings (Reid et al 1980).

    Post-mortem studies have shown plicae to occur in 20 – 50% of normal people (Hardaker, Whipple and Basset 1980, Wilhelm 1983, Zanoli and Piazzai 1983), with the highest incidence of people of Japanese descent (Mayeda 1918, Lino 1939, Aoki 1965, Sakakibara 1976, Jackson, Marshall and Fujisawa 1982). A 40 – 80% incidence of synovial plicae in arthroscopic examinations has been reported (Mizumachi, Kawaiashima and Okamura 1948, Broukhim et al 1979, San Dretto et al 1982, Johnson 1981, Dandy 1986).

    There is some controversy as to the prevalence of the plica syndrome and some reports even suggest that the pathological synovial plica does not exist, the plicae being a normal vestigial finding present in up to 60% of normal knees (Jackson 1980, Dandy 1981, Dandy 1986). Jackson, Dandy and others believe that plicae may be pathological but that over-diagnosis of the syndrome occurs, and many normal synovial shelves are removed (Jackson 1980, Hardaker, Whipple and Basssett 1980, Jackson, Marshall and Fujisawa 1982, Apple 1983, Zanoli and Piazzai 1983, Dupont 1985, Broom and Fulkerson 1986, Dandy 1986, Patel 1986, Lupi et al 1990). Dandy considered only 1% of synovial plicae to be associated with a symptomatic medial shelf syndrome, and that the other plicae are not pathological (Dandy 1986). Conversely other authors consider the plica syndrome to be a common cause of anterior knee pain and often mis-diagnosed. It has been claimed that the supra-patellar membrane is virtually never asymptomatic (Nottage et al 1983, Fujisawa, Jackson and Marshall 1976, Johnson 1981).

    Attempts have been made to quantify the occurrence of pathological plicae by analysing the histological findings of arthroscopic plical biopsies. Wilhelm reported histological findings of fibrosis indicative of chronic inflammation in 15% of a series of 186 medial shelf biopsies (Wilhelm 1983). Whilst Mital rpeorted plical haemorrhage in 9 of 16 biopsies (Mital and Hayden 1979).

    Sherman described a set of criteria for the diagnosis of pathological synovial plicae. The criteria consisted of: 1) a history of the appropriate clinical symptoms, 2) the failure of conservative treatment, 3) the arthroscopic findings of a plica with an avascular fibrotic edge which impinged on the medial femoral condyle during knee flexion, 4) no other knee pathology which would explain the symptoms (Sherman and Jackson 1989). However Jackson commented that the severity of symptoms is not proportional to the size or breadth of the synovial plica (Jackson, Marshall and Fujisawa 1982), and Richmond found no correlation between the duration of symptoms and the presence of pathological changes in the plica (Richmond and McGinty 1983). It has been suggested that an impingement lesion, which is a localised area of chondromalacia at the site of femoral condyle impingement is evidence that a plica is pathological.

    Detection of synovial plicae as the cause of anterior knee pain is dependent on recognition of the relevant clinical symptoms and the absence of signs except perhaps for a palpable tender synovial band. Plicae are not well seen on plain radiographs, but a double contrast arthrogram may demonstrate the supra-patellar membrane and a synovial shelf. Double contrast arthrography may demonstrate a supra-patellar plica in 20% of cases (Pipkin 1950, Apple et al 1982, San Dretto et al 1982, Aprin, Shapiro and Gershwind 1984, Lupi et al 1990). The arthrographic appearances of the anterior plicae are often mistaken for the anterior cruciate ligament (Brody et al 1983). A synovial shelf is more difficult to demonstrate by arthrography but the sky line view may demonstrate the synovial shelf (Deutsch et al 1981, De la Caffiniere, Thijn and Hillen 1984).

    Ultrasonography has been reported as having a sensitivity of 92% and a specificity of 73% in the detection of plicae (Derks, de Hooge and Van Linge 1986). A radio-isotope technetium bone scan may show some local increased uptake in association with an impingement lesion on the femoral condyle, but is otherwise normal (Brill 1984, Dye and Bell 1986). Computerised axial tomography (CT) has proven useful in the visualisation of the supra-patellar membrane but the synovial shelf or plica is easily missed (Boven, De Boeck and Potvliege 1983, Schutzer, Ramsey and Fulkerson 1986). The axial images of a Magnetic Resonance Scan (MRI) has in one study, proven to be a more useful mode of investigation than a CT scan for the detection of synovial plicae and chondromalacia (Passariello et al 1986). Radiographic and other modalities of investigation may be helpful in the clinical situation where the diagnosis is in doubt but are not routinely used in the detection of the plica syndrome which remains a clinical diagnosis confirmed during arthroscopy.

    The results of the treatment of anterior knee pain are notoriously difficult to assess objectively, primarily because a wide variety of conditions are usually gathered together under the category of anterior knee pain or chondromalacia patella (De Haven, Dolon and Mager 1979). In addition little account is taken of the reported natural improvement in the symptoms of anterior knee pain with time (Goodfellow, Hungerford and Woods 1976). Studies in this field must analyse the conditions included carefully and a randomised control group with long term assessment is necessary (Bentley and David 1984).

    The conservative treatment of the plica syndrome involves; quadriceps, hamstring and gastrocnemious stretching and isometric strengthening, cryotherapy, ultrasound, microwave diathermy, patellar bracing, bicycle riding, anti-inflammatory medication and an altered sports training schedule (Zanoli and Piazzai 1983, Newell and Bramwell 1984, Fisher 1986, Subotnick and Sisney 1986, Amatuzzi, Fazzi and Varella 1990). The results of such treatments in an uncontrolled study were an improvement in 40% of cases over a one year period (Rovere and Nichols 1985). Conversely Aprin suggested that, in knees in which an arthrogram demonstrated impingement of the plica on the femoral condyle in flexion, conservative treatment resulted in no long term improvement (Aprin, Shapiro and Gershwind 1984).

    Injection of the synovial plicae with steroid and local anaesthetic in another uncontrolled study gave excellent results in 73% of patients (Rovere and Adair 1985), although percutaneous injection of the thin intra-articular band of the plicae must be difficult and reliable placement impossible.

    Unfortunately all the historical studies on the surgical treatment of the plica syndrome are uncontrolled, non-randomised and often include a variety of pathologies (Patel 1978). Open knee arthrotomy and excision of the plica was first reported by Hughston (Hughston, Andrews and Waddell 1973) but has subsequently been reported by other authors (Patel 1978, De la Caffiniere, Mignot and Bruch 1981, Moller 1981). Arthrotomy has been superseded by the arthroscopic treatment of plicae which has been associated with good results in 60 – 90% of cases (Mital and Hayden 1979, Watanabe, Takeda and Ikeuchi 1979, Jackson, Marshall and Fujisawa 1982, Vaughan-Lane and Dandy 1982, Richmond and McGinty 1983, Zanoli and Piazzai 1983, Kinnard and Levesque 1984, Bough and Regan 1985, Koshino and Okamoto 1985, Broom and Fulkerson 1986, O’Dwyer and Peace 1988, Sherman and Jackson 1989). Arthroscopic plical excision has also been demonstrated to reduce the magnitude of the knee audiogram (Johnson 1981).

    Chondromalacia patellae is commonly found in association with synovial plicae (O’Dwyer and Peace 1988). This is thought to be an association of two separate conditions in the same population (Patel 1978, Hansen and Boe 1989). Some studies have demonstrated inferior results following arthroscopic plica surgery when other pathologies such as chondromalacia patellae or patello-femoral subluxation are simultaneously present in the knee (De la Caffiniere, Mignot and Bruch 1981, Vaughan-Lane and Dandy 1982, Richmond and McGinty 1988, O’Dwyer and Peace 1988, Sherman and Jackson 1989). The overlap between the plica syndrome, lateral retinacular pain and lateral facet hyperpressure syndrome is indistinct (Larson et al 1978, Schulitz, Hille and Kochs 1983) and the conditions may co-exist. The situation following surgery may be further confused by a lateral release performed for lateral retinacular pain or the lateral hyperpressure syndrome which may also divide any plicae present (Merchant and Mercer 1974, Larson et al 1978, McGinty and McCarthy 1981).

    The main complication reported following arthroscopic surgery for synovial plicae is recurrence of symptoms in 5% of cases (Richmond and McGinty 1983, Johnson et al 1984). This may result from reformation of the synovial band following simple incision of the plicae, or scar formation around the base of the excised plicae (Dandy 1981, Johnson et al 1984, Anderson and Poulson 1986). A case of lateral patella subluxation has been reported following over-zealous resection of a medial shelf and the medial retinacular structures (Limbird 1988).

    As yet the only scientific study which shows synovial plicae to be pathological or that division of the plicae is of any benefit to the patient as compared to the natural improvement in adolescent anterior knee pain which occurs with the passage of time is that reportedly the author (Johnson et al 1984). This study was able to determine that the synovial plicae of the knee are indeed a pathological entity rather than a normal variant, and was able to determine that arthroscopic division had a short and long term patient benefit when compared to a randomised control group.

    14 Patello-Femoral Arthritis

    Patello-femoral arthritis may be secondary to trauma, lateral hyperpressure, lateral patello-femoral subluxation, patello-femoral dislocation or osteochondritis dissecans of the patella. Posterior cruciate instability produces excessive load in the patello-femoral joint and may be associated with early degenerative change. Fixed flexion deformity of the knee or hip may also cause premature changes in the patello-femoral joint due to excessive patello-femoral contact force.

    Primary osteoarthritis of the patello-femoral joint may be particularly prevalent in pyrophosphate crystal arthropathy, pseudo gout or the hypertrophic variety of osteoarthritis. In both these conditions the patello-femoral joint may be affected by a florid and advanced arthritis whilst the tibio-femoral joint is well preserved.

    15 The Conservative Treatment of Anterior Knee Pain

    The conservative treatment of anterior knee pain must initially consider the extraneous causes. The running or playing surface may need changing at least temporarily such that jogging or running can be performed on grass or a soft surface rather than pavements or concrete. The shoe wear may be changed with specialised shoes used for activities such as road running. Additional custom made orthoses may be necessary to correct excessive foot pronation, metatarsalgia, hallux rigidus, calcaneal varus or valgus, equinus, femoral anteversion or external tibial torsion. 

    Physiotherapy should be directed towards flexibility, posture, muscular strengthening and the alleviation of inflammation. Objective isokinetic muscular assessment may be undertaken using a Kin-Com, Cybex or other similar computerised dynamometer. In these machines the muscle strength is tested throughout the range of motion and a graphic record of muscle function is produced. This graphic record may be compared to the results from the opposite side or with the results from the same side at different times during the rehabilitation. The muscular balance between the quadriceps and hamstrings muscles and between the concentric and eccentric modes of muscular contraction may be compared and rehabilitation specifically concentrated on the observed areas of weakness.

    In the discussion of this modality it is important to understand the terms used. Isometric exercises are undertaken with the maintenance of muscular contraction at a constant low length with variable loads. Isotonic activity is undertaken using muscular contraction against a constant load varying the speed and the length of the muscles. Isokinetic activity is undertaken with muscular contraction at a constant angular velocity. The load and length of the muscle are varied. Concentric muscular contraction is undertaken where shortening of the muscle length occurs against loads. Eccentric contraction is where the muscle lengthens against a load. A recent study demonstrates that the eccentric mode of isokinetic activity may be the most sensitive in diagnostic evaluation and also in muscular retraining.

    When using isokinetic measurement in the assessment of the various patterns of activity, the phased hamstring eccentric isokinetic analysis undertaken with an angular velocity of 180 degrees per second. A deficit in function is revealed particularly associated with loose bodies, torn lateral meniscus and osteochondral defects. Whereas synovial plicae characteristically cause a reduction in the peak torque generated between 40 and 80 degrees of flexion during eccentric quadriceps activity at 60 degrees per second, the investigation may also be used to assess the results of surgery in that the pattern of activity may be restored to normal after excision of a synovial plica or other pathology.

    The continual assessment is also useful during a rehabilitation phase to analyse the return of muscular strength and to determine when return to full activity is possible. This has been extensively used in association with the rehabilitation of anterior cruciate surgery whereby return to full sporting activities is usually allowed only after the attainment of 90% of the muscular strength of the normal side.

    Other mechanical and electrical modalities of physiotherapy such as cryotherapy, ultrasound and mega-pulse electro-therapy may be used when soft tissue inflammation is present. Patello-femoral bracing or taping to stabilise the patello-femoral joint or to correct lateral maltracking may relieve the pain from lateral patella tracking or patella subluxation. McConnell, an Australian physiotherapist, described a complete programme of patello-femoral rehabilitation which included retraining and strengthening the vastus medialis muscle using bio-feedback to promote vastus medialis action early in the phase of knee flexion.

    Such conservative therapy may be supplemented by non steroidal anti inflammatory medication as necessary, a steroid injection into extra-articular soft tissues and non weight bearing tendons may be of benefit. Injection into weight bearing tendons such as the Achilles tendon should be discouraged as rupture may be precipitated. Repeated intra-articular injections have been reported to result in damage to the articular cartilage and should be avoided. Temporary periods of rest may also alleviate the symptoms.

    There are studies which suggest that conservative treatment in anterior knee pain may result in an initial improvement in up to 87% of patients. However this diminishes to 60% on follow up at 3 months. A study by Goodfellow et al demonstrated that, in a cohort of female patients with anterior knee pain, 49% of patients improved following an average 16 month duration of conservative therapy (Goodfellow et al). However it was also noted that 96% of patients retain some anterior knee pain at final follow up.

    In a recent study undertaken by the author in patients with synovial plica syndrome, improvement occurred in only 28% of patients over a 2 year period treated by diagnostic arthroscopy and conservative measures (Johnson et al 1984). This compares with a 96% improvement following surgical division of the synovial plica. Thus the expected improvement in the symptoms of anterior knee pain with time may be sustained by hope and frustration rather than any objective evidence.

    16 The Surgical Treatment of Anterior Knee Pain

    The surgical treatment of anterior knee pain may include excision of the degenerative area within the patellar tendon in patellar tendonitis. The central portion of the patellar tendon may be released from the inferior pole of the patella although this may be unnecessary and may reduce the strength of the patellar tendon. Peri-patellar bursitis may be treated by aspiration, injection or excision if necessary. Arthroscopic surgery may be undertaken to remove anterior meniscal tears, remove meniscal cysts, decompress meniscal cysts, remove loose bodies in the front of the knee and debride areas of osteochondritis dissecans.

    Cruciate ligament reconstruction may alleviate the anterior knee pain associated with anterior or posterior cruciate ligament laxity. However, any retro-patellar articular degeneration may not be reversible. Following anterior cruciate ligament reconstruction using either the central third of the patellar tendon or a hamstring tendon reconstruction technique, an instance of post operative anterior knee pain has been noted. Attention to detail during surgery may reduce this incidence. Arthroscopy and arthroscopic excision of the fat pad may be undertaken in Hoffa’s syndrome where the hypertrophic fat pad or infra-patellar xanthoma may be removed. The condition of peri-patella pannus formation or quadriceps fibrosis where an excessive fibrous reaction occurs in the synovium around the patella. The hypertrophic synovium encroaches into the patello-femoral joint causing impingement and pain. Local synovectomy may be of benefit. In similar way, synovial tumours such as lipoma, pedunculated fibromas, intra-articular xanthomas and areas of pigmented villo-nodular synovitis may be arthroscopically excised. It may also be possible to remove benign bony tumours around the knee such as solitary enchondroma arthroscopically.

    In the condition of lateral patellar hyperpressure syndrome, lateral patellar tilt and lateral patello-femoral facet chondromalacia, lateral retinacular pain, lateral retinacular nerve injury or patello-femoral subluxation, arthroscopic lateral retinacular release may give symptomatic relief.

    17 Patello-Femoral Subluxation

    Minor degrees of patello-femoral subluxation without dislocation, may be relieved by arthroscopic lateral release although there is a described incidence of recurrence. Risk factors include multiple ligamentous laxity, patella alta, hyperplastic femoral condyle, increased ‘Q’angle, external tibial torsion, persistent femoral anteversion or an avulsed and ruptured vastus medialis. In athletes having sustained a single dislocation of the patello-femoral joint, However it is generally advised that undertaking early knee arthroscopy, drainage of the haematoma, debridement of any articular damage and arthroscopic lateral release followed by early rehabilitation including quadriceps strengthening exercises is good practice. Empirical lateral release for anterior knee pain is undertaken in some centres but must be strongly discouraged, as inappropriate lateral release may produce medial patella dislocation and other problems.

    In patients with recurrent patello-femoral subluxation, as an initial procedure use arthroscopic lateral release in isolation unless multiple ligamentous laxity or other gross deformity is present. In the presence of risk factors or multiple ligamentous laxity, I prefer to combine arthroscopic lateral release with repair of the vastus medialis and transposition of the vastus medialis to the anterior medial surface of the patella. Combine this with an extra-articular modified Elmsley-Trillat procedure in which the tibial tuberosity is elevated on a distal base, rotated medially and fixed with a single screw. In many instances, if fixation is adequate, early rehabilitation can be undertaken without the need for an immobilisation in a plaster cast or splint. Discharge from hospital may take place after 1 or 2 nights and early return to full activity after only 6 weeks may be expected. This procedure leaves only two 2 cm long scars at the superior medial border of the patella and to the lateral side of the tibial tuberosity. There is minimal inhibition of the quadriceps muscle and no ugly deformity or scarring of the knee results.

    18 Chondromalacia

    Arthroscopic surgery for chondromalacia or articular cartilage defects in the patello-femoral joint is difficult and the results of such treatment are not well defined. Generally loose articular fronds and fragments may be removed. Any articular cartilage adherent to the subchondral bone may be assumed to be functional and should not be removed only to improve the visual appearances. Abrasion chondroplasty or articular drilling with a 1 mm drill are the techniques for abrading the exposed subchondral bone in the base of articular defects in order to promote the ingress of fibrous tissue. This tissue may cover the exposed bone and provide a new articular surface composed of fibrous scar tissue. This may in some cases relieve for a time the pain experienced. The fibrous tissue is never as good as articular cartilage and therefore excision of the loose articular fragments and fronds should be kept to a minimum. It is suggested in the literature that the maximum area of exposed bone which may be helped by an abrasion chondroplasty may be as small as 1 cm in diameter.

    Chondromalacia of the femoral trochlear groove presents a difficult problem. This situation is commonly found in association with netball, basketball and Australian Rules football which require jumping. Abrasion chondroplasty is usually undertaken.

    Arthroscopic surgery for chondromalacia in other sites should also be directed to the primary cause if one is present. If the chondromalacia is secondary to lateral hyper-pressure, lateral patello-femoral subluxation or dislocation, then this is treated while the chondromalacia is merely debrided. In the presence of chondromalacia of the central ridge or more generalised over the whole patella there is usually no definable cause treatable by arthroscopy, and this may be resistant to all other measures. In this situation subsequently a Macquet type advancement of the tibial tuberosity may be undertaken in mature patients. This should only be undertaken after due consideration in view of the ugly scar, the resulting deformity of the knee and the expected success in only 50% of patients.

    19 Patellectomy

    Surgical removal of the patella or patellectomy should be avoided if at all possible despite persistent anterior knee pain. There is persistent weakness of the quadriceps muscle which has been estimated to be as much as 30% which results in poor function, and in addition, excessive compressive forces are transmitted to the tibio-femoral joint and acceleration of any degenerative change in the knee joint occurs. Although total knee replacement in the absence of a patella is technically possible the resulting function is poor. Patellectomy is associated with persistent knee pain, the formation of bone fragments beneath the patellar tendon which may cause persistent anterior knee pain. Late debridement and lateral release of the repaired quadriceps/patellar tendon may be necessary because of persistent anterior knee pain, lateral retinacular pain, lateral tendon subluxation and restricted knee flexion.

    20 Effectiveness of Treatment for Anterior Knee Pain

    Conservative management for anterior knee pain is sufficient and adequate for approximately 50% of patients, of those remaining a clinically definable pathology is present in perhaps 80% to 90% of patients. Of these patients, a significant proportion may be amenable to surgical therapy. There does, however, remain a proportion of patients complaining of anterior knee pain in which no definable pathological cause or effective treatment may be found. In these cases, reflex sympathetic dystrophy must be considered in a small proportion, although the treatment of reflex sympathetic dystrophy is difficult. 

    21 Conclusion

    The management of anterior knee pain demands an understanding of the numerous pathological entities which may cause it. A careful relevant history and examination is necessary. If properly organised conservative treatment is unsuccessful a variety of surgical procedures are available. Successful treatment may be possible in up to 90% of patients, whereas without proper treatment there is little evidence that the symptoms will settle without treatment. Adequate treatment my be successful in a significant proportion of cases and in some conditions such as lateral patella tilt and hyper-pressure, the progression to patello-femoral arthritis may be avoidable. The attitude held by some practitioners that anterior knee pain is a self limiting condition in patients with underlying neurotic personalities should be discounted, discarded and condemned to the historical archives of orthopaedic surgery.

Current research topics

  1. Patellar Tendonitis:

    I have a long-term research interest into the condition of patellar tendonitis. I started researching into the subject in 1990. He first published a study on the MRI appearances, the anatomy and morphology of patients with this condition. This paper was entitled “Radiographic and Magnetic Resonance Imaging Analysis of the Morphology of Patellar Tendonitis”. This was published in The Knee, Volume 2 (1), 1995, 61-62. Further research was published the following year “Magnetic Resonance Imaging of Patellar Tendonitis” which was published in The Journal of Bone and Joint Surgery (British), 78/b, May 1996, 452-7.

    Subsequently in association with my clinical Fellow, Mr Oreste Basso, a visiting surgeon from Italy, a paper on the anatomy of the patellar tendon was published “The Anatomy of the Patellar Tendon” in a Springer Verlag on line publication in October 2000 and subsequently in Knee Surgery, Sports Traumatology and Arthroscopy, Volume 9, 1, January 2001, 2-5. Subsequently again with Mr Oreste Basso and Professor Andrew Amis of The Imperial College, London, a series of biomechanical studies were undertaken on the micro structure and biomechanics of the patella and the patellar tendon and the influence on patellar tendon and the patellar tendonitis and the surgery for this condition.

    Published papers included “Patellar Tendon Fibre Strain: The Differential Responses to Quadriceps Tension” published in Clinical Orthopaedics and Related Research, (400), 246-53, 2002 July. Subsequent papers have been submitted including “Arthroscopic Treatment of Patellar Tendonitis: A New Treatment” and “The Patella Apex Impingement Pressure on the Patellar Tendon In Vitro and its Relation to Pathological Lesions of Patellar Tendonitis”.

    As a result of the extensive research into the condition I designed a new arthroscopic, keyhole or minimally invasive procedure for the treatment of this condition. The procedure included decompression of the inferior pole “impingement” by a technique utilising key-hole surgery or arthroscopy. I first undertook this new procedure of decompression of the inferior pole of the patella in 1990. Subsequently others have published and presented this new technique around the world and it has been adopted in many leading centres worldwide as the technique of choice in treating patellar tendonitis. I have lectured around the world on this subject.

    Further development of this project is proposed to include:

    • The epidemiological analysis in a population at risk, of the anatomical aspects of this condition in relation to patella-tendon flexion angle, innate flexibility and physical exercise.
    • A histological assessment of the collagen changes within the tendon occurring in this condition.
    • An assessment of the non-operative treatment of this condition in the community incorporating patient education, flexibility training and physiotherapy. In order to undertake this it is proposed to utilise my association with the Football association.
  2. The use of Bioabsorbable screw fixation in Anterior Cruciate Ligament Surgery.

    The results of ACL reconstruction have been analysed over a five year period and a sequence of studies into the success and long term tissue compatibility of poly-glyconates in this situation has been analysed.  New developments include the recent development of fourth generation poly-l-lactic acid screws which incorporate poly-l-lactic acid granules and calcium phosphate coatings in an effort to produce dissolution channels and peripheral buffer to alleviate the problems of internal dissolution. My own clinical and histological assessment is awaiting correlation and subsequent publication. It is proposed that the further funding of this project would be sought from contacts within the industry and the further development of this project would include:

    • The clinical assessment of the long term results from use of these screws in a single surgeon cohort. Investigation for cavitation, internal dissolution and detection of any reaction to the acidic cleavage radicles.
    • Clinical, biomechanical and biochemical assessment of the fourth generation PLA/PGA/CaPO4 screws and the mechanism of dissolution
  3. Osteochondral and Osteocyte Transplantation

    The new techniques of Osteochondral and osteocyte transplantation have been analysed over a period of six years. I have presented my results of the clinical outcome around the world. New techniques in MRI analysis of articular cartilage lesions have been developed, used clinically and recently reported. This work continues and is planned to be developed in association with basic scientists and rheumatologists into various areas:

    • Use of imaging techniques to identify and categorise the articular cartilage defects and document changes following reconstruction.
    • Investigate the use of histological markers for categorising cartilage defects and their progress.
    • Investigate the use of biotechnology to enhance incorporation of osseous  and articular cartilage transplants.
    • Investigate the use of bone composites in the reconstruction of articular cartilage defects.
  4. The effects of patellar realignment on anterior knee pain and isolated patello-femoral arthritis.

    The increasingly troublesome problem of isolated lateral facet osteoarthritis of the patello-femoral joint is becoming increasingly recognised.  A project has been in progress for some time analysing the clinical and functional results of realignment at an early stage and the long term effects on the progression of the arthritis. This is planned to be developed into:

    • A epidemiological study of the prevalence and effect of this condition and the relationship to patello-femoral congenital malalignment.
    • A study of the biochemical markers in chondromalacia and patello-femoral malalignment and the effect of non-operative and operative treatment on these markers.
    • A biomechanical study of the effect of sequential soft tissue realignment of the patello-femoral joint, and the effects of tibial tuberosity transfer.
    • A clinical study of the effectiveness of patello-femoral realignment in patello-femoral subluxation and malalignment, and patello-femoral arthritis.
  5. Dyslexia and its relation to Spatial-cognitive awareness in MIS surgery

    Perhaps my most interesting and significant project has been under development for some years and is at a very rudimentary stage. The preliminary results have been presented in 2014. The topic is increasingly applicable to the current thrust of medical education, training and continual assessment for competence, and it is especially relevant for the accreditation and continual assessment for minimally invasive surgery. This is a project which excites me more than any other.

    The potential of this finding is I believe enormous and demands further investigation. It would be suitable for a major research grant to progress this idea in respects of:

    • Analysis of medical school entrants and spatial cognitive skills, their performance in relation to MCQ / Essay and subject strengths. The relationship of this to success in surgical training and MIS. A similar analysis of rejected medical school candidates for aptitude in this respect.
    • An analysis of the character and personality of medical school entrants and dyslexic personality traits and the relationship of this to career choice and current GMC parameters including team working and communication skills.
    • A comparative analysis of the spatial cognitive skills, communication skills  and character traits of a surgical consultant population and those dedicated to MIS as compared with medical and non practical aspects of medicine.
    • Historically the assessment of surgical skill has proved problematical. However utilisation of spatial cognitive awareness rather than manual dexterity may well be more reliable. One of the existing methods of assessment of spatial cognitive awareness and manual skill will be used to develop a verifiable program of assessment of spatial cognitive awareness and MIS surgical skills.
    • Development of this assessment program into a verifiable tool of accreditation, appraisal and reassessment for MIS manual dexterity in surgery.

     

     

  6. Use of Oxinium technology in Total Knee Replacement

    Recently a new material of oxidised alloy of zirconium with a ceramic surface has been developed for Knee Replacement. This is potentially a significant advance in terms of the bio-mechanical properties and reduction in wear and allergy problems in joint arthroplasty. Work is in progress to assess the clinical effectiveness and advantages of the use of this material. This is currently funded by industry with research grants for personnel. Further development requiring substantive funding is proposed along the following lines:

    • Biomechanical development of an osteoconductive surface for uncemented use. This requires a multidisciplinary approach incorporating materials and manufacturing science, bio-engineering and subsequent veterinary experimentation.
    • Histological, biochemical and use of biomechanical markers to follow the clinical use of this material.
    • The clinical assessment of this material in terms of function, rehabilitation, wear and markers of inflammation and allergy over time.
  7. Infection prophylaxis in orthopaedics.

    Having completed my thesis on the prevention and treatment of prosthetic infection in Joint Arthroplasty, the conclusions prompted several changes to clinical practice which were implemented around the world.  However it is hoped that with further support from Glaxo Pharmaceuticals a major research project will be undertaken analysing the basic science of the role of local tissue oxygen metabolism, local biochemistry, the “biofilm” and mediators of orthopaedic infection. This would be directed towards a new type of chemical infection prophylaxis and treatment measures. The outline would include:

    • Utilisation of a biofilm culture on a prosthetic surface and an analysis of the effects of changing the physical surface characteristics and chemical parameters. This would include an assessment of biofilm integrity and cell adhesiveness by electron microscopy.
    • Analysis of the use of chemical prophylaxis and treatment upon the biofilm culture.
    • Analysing the effect on the biofilm call culture by the additional effect on enhanced host cellular activity. This would include varying the physical environment parameters and utilising measures in association with basic scientists to enhance the activity and effectiveness of the macrophage cell culture.

My best research work would include:

  1. DP Johnson. Acta. Orthop. Scan. Supplement. April 1993: Vol 64; 252.

    My MD thesis: Infection and Failed Wound Healing Following Knee Arthroplasty. University of Manchester  M.D. 1990. This was exceptionally published in full as a supplement to the Acta Orthopaedics Scandinavica in 1993: Infection and Wound Healing Following knee Arthroplasty. DP Johnson.  Acta. Orthop. Scan.  Supplement.  April 1993: Vol 64; 252. The final section and the conclusion was I think the most important and this was only published in the thesis itself. This showed that the primary determinant of all the different factors affecting postoperative healing and infection is the maintenance and restoration of tissue oxygenation in the wound was only published in the thesis. I have been told through that this did change surgical techniques around the world.

  2. Antibiotic Prophylaxis With Cefuroxime In Knee Arthroplasty. DP Johnson Journal Of Bone and Joint Surgery (Br) 1987 – Vol 69 – 787-9

    Another paper which altered surgical techniques forever was my paper which first demonstrated that the tourniquet had an important effect on the timing of antibiotic prophylaxis administration.

  3. Symptomatic Synovial Plicae of the Knee: Fact or Fiction. DP Johnson, DM Eastwood, PJ Witherow. Bone Joint Surg. (Am); Oct 1993: 75-A; 1485-96.

    The paper I had most fun writing was one with a rhetorical title: Symptomatic Synovial Plicae of the Knee: Fact or Fiction. DP Johnson, DM Eastwood, PJ Witherow.  Bone Joint Surg. (Am); Oct 1993: 75-A; 1485-96. This stepped into a minefield of anterior knee pain and it’s treatment in the commercial environment. Synovial Plica was [perhaps the most controversial area of modern arthroscopic surgery. This paper demonstrated in an NHS setting that in a properly controlled prospective study that in a properly selected adolescent patient group the vast majority of patients with this aetiology of anterior knee pain was curable by simple arthroscopic surgery. It was so controversial that the American journal took more than a year reviewing and analysing the data before publication. Again it altered surgical techniques around the world.

  4. Microsurgical Expertise, Visuo-spatial skills and Dyslexia: Are They Related? SJ Pickering, SE Gathercole, DP Johnson. Fourth International Conference of British Dyslexia Association. York. April 1997

    This super successful group of perhaps the top earning medical practitioners in the world proved as I suspected to be disproportionately dyslexic particularly so since the introduction of arthroscopic surgery as a principle part of a knee surgeons work. This questions what skills, psychometric and personality profiles are best suited for orthopaedic surgeons and questions whether the current entry assessment of entry are appropriate.

Other published research

  1. Thesis, Patents and Text Books

    MD THESIS: Infection and Failed Wound Healing Following Knee Arthroplasty.

    University of Manchester  M.D. 1990

    TEXT BOOKS: Controversies in Orthopaedics: Knee Surgery

    Eds: D P Johnson.   R J Williams MD. Hospital for Special Surgery NY.

    Oxford University Press.  Sept 2004

    PATENTS: A New Inset Patella Prosthesis for Total Knee Replacement.

    Anterior Cruciate Ligament Fixation and Tensioning Device.

    THESIS SUPERVISED Mr. O. Basso. Patellar Tendonitis. Imperial College

    Department of Bioengineering Imperial College London2001

  2. BOOKS

    Commissioned by the Oxford University Press Dec 2003

    Controversies in Soft Tissue Surgery of the Knee.

    Co-Editors DP Johnson, Riley Williams. Prof of Orthopaedics. Hospital for Special Surg. New York.

    Awards: BMA Medical Text Book Competition 1995: “Highly Commended” International Section.

    Reviewed Acta Orthop Scan 2005; 76 (5): 730. Dr R Heijboer “For the knee surgeon this work can be considered as a reference…to the treatment of ligament problems”.

    Infection and Wound Healing Following knee Arthroplasty.

    DP Johnson.  Acta. Orthop. Scan.  Supplement.  April 1993: Vol 64; 252.

  3. CHAPTERS IN BOOKS:

    Pathological Synovial Plica of the Knee:  Fact or Fiction. DP Johnson,  DM Eastwood,  PJ Witherow.Surgery and Arthroscopy of the Knee.  Springer-Verlag, Heidleberg, 1992.

    Continuous Passive Motion Following Knee Arthroplasty. DP Johnson. Surgery and Arthroscopy of the Knee.  Springer-Verlag, Heidleberg, 1992.

    Transcutaneous Skin Oxygen Tension Analysis Of The Viability Of Incisions For Knee Arthroplasty.

    DP Johnson.  Surgery and Arthroscopy of the Knee. Eds: Muller W and Hackenbruch W.

    Springer-Verlag, Heidleberg, 1988. 657-60.

    Patellar Subluxation Following Kinematic Knee Arthroplasty:  Is The Universal Instrument System Universal? DP Johnson.  Surgery and Arthroscopy of the Knee. Eds: Muller W and Hackenbruch W.

    Springer-Verlag, Heidleberg, 1988. 76-7.

    Continuous Passive Motion Following Knee Arthroplasty.  DP Johnson.  Recent Advances in Prosthetic Surgery.  Ed: R Coombs. Butterworths 1989.

    Antibiotic Absorption Under Tourniquet. DP Johnson, GC Bannister, J Auchincloss, J Newman.

    Surgery and Arthroscopy of the Knee. Eds: Muller W and Hackenbruch W.  Springer-Verlag, Heidleberg, 1988. 630-1.

    Infection prophylaxis In Surgery. P Johnson.  Infectious Diseases Update. Exerpta Medica Asia.  Hong Kong 1988.

    The Outcome Of Infected Arthroplasty Of The Knee. P Johnson, GC Bannister.  Surgery and Arthroscopy of the Knee. Eds: Trickey E. and Hertel P. pringer-Verlag, Heidleberg, 1986. 358-60.

  4. REVIEW ARTICLES BY INVITATION

    Knee Injuries in the Primary Care Setting

    The Practitioner 2006 ; Vol. 250: In press

    Knee Surgery:  Current Practice.

    D.P. Johnson.  New England Journal of Medicine. July 29: 1993.

    Biomechanical Factors Affecting Wound Healing Following Knee Arthroplasty.

    D.P. Johnson, D. Bader, D.M. Eastwood.  J.  Medical Engineering and Technology.  1991:  15;  8-14.

  5. PUBLICATIONS as listed in PubMed: http://www.ncbi.nlm.nih.gov/pubmed/advanced

    Diagnosing shoulder pain.

    Barnes J, Dunkley A, Johnson DP. Practitioner. 2009 Jan;253(1714):26-30. No abstract available.

    Diagnosis and management of knee injuries.

    Johnson DP. Practitioner. 2006 Nov;250(1688):4-6, 9, 13-4 passim. Review. No abstract available.

    Reconstruction of the lateral patellar retinaculum following lateral release: a case report.

    Johnson DP, Wakeley C. Knee Surg Sports Traumatol Arthrosc. 2002 Nov;10(6):361-3. Epub 2002 Sep 11.

    Patellar tendon fiber strains: their differential responses to quadriceps tension.

    Basso O, Amis AA, Race A, Johnson DP. Clin Orthop Relat Res. 2002 Jul;(400):246-53.

    The outcome of intra-articular debris, following anterior cruciate ligament reconstruction.

    Basso O, Johnson DP, Jewell F, Wakeley CJ. Knee. 2001 Oct;8(3):235-7.

    The anatomy of the patellar tendon.

    Basso O, Johnson DP, Amis AA. Knee Surg Sports Traumatol Arthrosc. 2001;9(1):2-5. Erratum in: Knee Surg Sports Traumatol Arthrosc 2001;9(1):56.

    Magnetic resonance imaging of patellar tendonitis.

    Johnson DP, Wakeley CJ, Watt I. J Bone Joint Surg Br. 1996 May;78(3):452-7.

    The value of MR imaging in the diagnosis of the os trigonum syndrome.

    Wakeley CJ, Johnson DP, Watt I. Skeletal Radiol. 1996 Feb;25(2):133-6.

    Displaced femoral neck stress fracture in a marathon runner.

    Kerr PS, Johnson DP. Injury. 1995 Sep;26(7):491-3. No abstract available.

    Symptomatic synovial plicae of the knee.

    Johnson DP, Eastwood DM, Witherow PJ. J Bone Joint Surg Am. 1993 Oct;75(10):1485-96.

    Infection after knee arthroplasty. Clinical studies of skin hypoxia and wound healing.

    Johnson DP. Acta Orthop Scand Suppl. 1993;252:1-48. No abstract available.

    Beneficial effects of continuous passive motion after total condylar knee arthroplasty.

    Johnson DP, Eastwood DM. Ann R Coll Surg Engl. 1992 Nov;74(6):412-6.

    Patellar complications after knee arthroplasty. A prospective study of 56 cases using the Kinematic prosthesis.

    Johnson DP, Eastwood DM. Acta Orthop Scand. 1992 Feb;63(1):74-9.

    Percutaneous release of the trigger finger: an office procedure.

    Eastwood DM, Gupta KJ, Johnson DP. J Hand Surg Am. 1992 Jan;17(1):114-7.

    Lateral patellar release in knee arthroplasty. Effect on wound healing.

    Johnson DP, Eastwood DM. J Arthroplasty. 1992;7 Suppl:427-31.

    Biomechanical factors in wound healing following knee arthroplasty.

    Johnson DP, Eastwood DM, Bader DL. J Med Eng Technol. 1991 Jan-Feb;15(1):8-14. Review.

    The effect of continuous passive motion on wound-healing and joint mobility after knee arthroplasty.

    Johnson DP. J Bone Joint Surg Am. 1990 Mar;72(3):421-6.

    Antibiotic prophylaxis during bilateral knee arthroplasty: brief report.

    Johnson DP, Donell ST. J Bone Joint Surg Br. 1988 Aug;70(4):666-7. No abstract available.

    Midline or parapatellar incision for knee arthroplasty. A comparative study of wound viability.

    Johnson DP. J Bone Joint Surg Br. 1988 Aug;70(4):656-8.

    The timing of tourniquet application in relation to prophylactic antibiotic administration.

    Bannister GC, Auchincloss JM, Johnson DP, Newman JH. J Bone Joint Surg Br. 1988 Mar;70(2):322-4.

    Fracture-dislocation of the ankle with rupture of the deltoid ligament.

    Johnson DP, Hill J. Injury. 1988 Mar;19(2):59-61.

    Antibiotic prophylaxis with cefuroxime in arthroplasty of the knee.

    Johnson DP. J Bone Joint Surg Br. 1987 Nov;69(5):787-9.

    Anterior midline or medial parapatellar incision for arthroplasty of the knee. A comparative study.

    Johnson DP, Houghton TA, Radford P. J Bone Joint Surg Br. 1986 Nov;68(5):812-4.

    Early diagnosis of atlanto-axial rotatory fixation.

    Johnson DP, Fergusson CM. J Bone Joint Surg Br. 1986 Nov;68(5):698-701.

    The outcome of infected arthroplasty of the knee.

    Johnson DP, Bannister GC. J Bone Joint Surg Br. 1986 Mar;68(2):289-91.

  6. OTHER PUBLICATIONS

    Arthroscopic Treatment of Patellar Tendonitis: A New Treatment. DP Johnson,  Arthroscopy in preparation March

    MRI Analysis of Osteochondral Transplantation with Donor Site Reconstruction – a new Surgical Technique.

    S. Bernard, C. Wakeley, D. Johnson.  In preparation The Knee March

    Is impingement on the patellar tendon a mechanical factor in patellar tendonitis?

    O. Basso,  AA Amis, DP Johnson.  Clin. Orth. Rel. Res. March 2004.

    Patellar tendon Fibre Strain: their differential responses to quadriceps tension.

    O. Basso,  AA Amis, A Race, DP. Johnson. Clin. Orthop. Rel. Res.. (400); 246-53 2002 Jul.

    The Anatomy of the Patellar Tendon. O Basso,  DP Johnson,  A Amis. Springer Verlag on Line Publication. Oct 2000.

    Costs of League Soccer Injuries. DP Johnson.  Br. J. Sports Medicine 1998; 32: 332.

    Combined High Tibial Osteotomy and Extra-articular Tenodesis for the Cruciate Deficient Degenerative Knee.

    DP Johnson. The Knee.  Vol 3. July 1996. 9-14.

    Heterotopic Ossification of the Peri-patellar Pannus Following Knee Arthroplasty.

    DP Johnson. The Knee.  Vol 3. July 1996. 45-8.

    MRI Findings in Suspected Achilles Tendonitis.

    SJ Freeman, CJ Wakeley, I Watt, D Johnson.  Skeletal Radiology Vol 25(2); 1996; 133-136.

    Radiographic and Magnetic Resonance Imaging Analysis of the Morphology of Patellar Tendonitis.

    PR Johnson, I Watt, C Wakeley. The Knee Vol 2(1); 1995: 61-61.

    Patellar Subluxation With The Kinematic Prosthesis:  Are The Universal Instruments Universal.

    DP Johnson,  DM Eastwood.  J. Arthroplasty 1994.

    Patellar Complications After Knee Arthroplasty.

    DP Johnson,  DM Eastwood.  Acta Orthop Scand.  1992; 63:1: 74-9.

    Beneficial Effects of Continuous Passive Motion Following Total Condylar Knee Arthroplasty.

    DP Johnson. D.M. Eastwood.  Ann Royal Coll. of Surgeons of England:  1992; 74: 412-416.

    Percutaneous Release of the Trigger Finger: an office procedure.

    DM Eastwood,  DP Johnson.  J. Hand Surg.   Jan. 1992; 17:1: 114-7.

    Rotary Fixation Of The Atlanto-Axial Joint. DP Johnson and  C. Fergusson.  Journal of Bone and Joint Surgery [Br]. 1986: Vol 68: 698-701.

    Massive Dapsone Overdosage: A Case Study. DP Johnson.  Postgrad. 1982: Vol 4: 3.

    Paracetamol Induced Hepatic Necrosis With Normal Doseage. DP Johnson.  Postgrad. 1981:Vol 4: 2.

    Total Parenteral Alimentation Of The Neonate. DP Johnson.  Regional Neonatal Surgical Unit. Saint Marys Hosp, Manchester 1978.

  7. PUBLISHED ABSTRACTS:

    The Psychometric Assessment of Arthroscopic Surgeons

    Johnson JJS, Johnson DP. Abstarct book ACL Study Group Meeting Cape Town 2014.

    The MRI features of Osteochondral Transplantation with donor site reconstruction- a new surgical technique.

    S Bernard, C Wakeley, DP Johnson, SP Prabhu. Skeletal Radiology Vol 34, No 9, Sept 2005: 575.

    Osteochondral Transplanatation with donor site reconstruction and MRI analysis.

    DP Johnson, C Wakeley, S Bernard. British Orthopaedics Association Cardiff Sept 2002-09-20

    JBJS [Br] 2003; 85-B: Supp II;  167

    ACL Study Group. Big Star Resort. Montana. March 2002 abstract book

    3rd International Instructional Course. Basle Feb 2003 Abstract book.

    10 year experience with Arthroscopic Surgery for Patellar tendonitis.

    DP Johnson. AOSSM Orlando. USA. July 2002

    JBJS [Br] 2003; 85-B: Supp II;  162

    ISAKOS Aukland NZ March 2003 Abstract book.

    Biomechanical Analysis of the Surgical procedures for the Management of Patellar Tendoinitis.

    O Basso,  AA Amis,  DP Johnson. ESSKA Rome April 2002.

    Arthroscopic Surgery for Patellar Tendonitis: A One to Four Year Follow up study. D.P. Johnson
    J. Bone Joint Surg. [Br] 1999; 82-B:Supp 1: 20.

    Arthroscopy Vol 15, No 7, Supply 1. Oct 1999; S19.

    Abstract Book: World Congress On Orthopaedic Sports Trauma. Brisbane April 2000.

    Differential Stain in the Anterior and Posterior Fascicles of the Patellar Tendon: A causative Factor in Patellar Tendonitis. O. Basso,  DP. Johnson,  A. Amis.

    Abstract Book: World Congress On Orthopaedic Sports Trauma. Brisbane April 2000.

    A Five Year Follow Up of Arthroscopic Surgery for Patellar Tendonitis. D.P. Johnson.

    Abstract Book.  Patello-femoral Study Group 1998.

    Arthroscopy 1998; 14:S44.

    Arthroscopic Surgery for Patellar Tendonitis:  A New Technique DP Johnson.  O. Basso.

    J. Bone joint Surg. [Br] 1998; 80-B:Supp 1: 46.

    The Anatomy of the Patellar Tendon:  A Macroscopic Study. O. Basso,  DP. Johnson,  A. Amis.

    J. Bone joint Surg. [Br] 1998; 80-B:Supp 1: 101.

    Operative Complications from the Use of Biodegradeable Kurosawa Screws. DP Johnson.

    J. Bone joint Surg. [Br] 1998; 80-B:Supp 1: 103.

    Arthroscopic Surgery for Patellar Tendonitis. DP Johnson.

    J. Bone joint Surg.  Proc.  1996: 78 B; 144.

    Arthroscopy Vol. 14, No2, Suppl 1. 1988, S44.

    Operative Complications from the Use of Biodegradeable Kurosawa Screw. D.P. Johnson

    J. Bone joint Surg.  Proc.  1998.

    MRI,  Arthroscopy and Histological Appearances in Osteochondritis Dissecans. D.P. Johnson.  S. Ansari.   SICOT Lon. 1996.

    EFFORT. Barcelona. J. Bone joint Surg.  1997; 79-B:Supp 2: 181.

    The Anatomy of the Patellar Tendon. O. Basso,  DP. Johnson,  A. Amis.

    Abstract book. Br. Orthop. Res. Soc. Brighton. Sept. 1996.

    J. Bone joint Surg. [Br] 1997; 79-B:Supp 3: 360 – 61.

    Partial  Rupture of the Anterior Cruciate ligament. SJ Freeman,  CJ wakeley,  I Watt,  DP Johnson.

    Abstract book 7th ESSKA Congress.  Budapest,  Hungary  May 1996:  68.

    MRI findings in suspected achilles tendonitis.

    Abstract book;  Rontgen Centenary Congress.  Birmingham  1995

    British Journal of Radiology;  1995: 202.

    Magnetic Resonance Immaging of Patellar Tendonitis. S. Freeman,  C. Wakeley,  I. Watt,  D.P. Johnson.

    British Journal of Radiology;  1995.

    Athroscopic Surgery for Patellar Tendonitis. D.P. Johnson.

    The Magellan Society Abstract Book.  Stockholm 1995.

    Radiological and MRI Analysis of the Morphology of Patellar Tendonitis. D.P. Johnson,  C.Wakeley and I. Watt.

    Proceedings of the British Orthopaeddic Sports Trauma Association.

    J. Bone Joint Surg. [Br]: 1994;76-B:SUPP 2; 142.

    AOSSM Orlando 1996 Proceedings.  AOSSM Philladelphia.

    Osteo-chondritis Dessicans – MRI Appearance Compared with Radiographic Arthroscopic and Histological Charachteristics. DP Johnson,  S Ansari,  T Wickremeratchi,  C Wakeley.

    International Symposium on Recent Advances In Arthroscopic Surgery.  Riyadh  Nov 1994.

    Patellar Complications After Knee Arthroplasty – A prospective study of 56 cases using the kinematic

    prosthesis. DP Johnson,  DM Eastwood.

    Current Opinion in Rheumatology, 5; 5; May 1993.

    Percutaneous Release of the Trigger Finger:  An Office procedure. DM Eastwood,  DP Johnson.

    In Press;  J. Bone Joint Surg.  [Br] 1992.

    Infection in Knee Arthroplasty:  A comparison of Antibiotic Prophylaxis Plain and Gentamicin- Containing Cement. BA Coghlan,  DP Johnson,  T Wood.

    J. Bone Joint Surg.  [Br] 1991: 73-B: Supp 1; 74-5.

    Pathological Synovial Plica of the Knee:  Fact or Fiction. DP Johnson,  DM Eastwood,  PJ Witherow.

    In Press;  Orthopaedic Transactions.  J. Bone Joint Surg.  [Am] 1992.

    In Press:  Abstract Book; First World Congress of Sports Trauma.  1992

    J. Bone Joint Surg.  [Br] 1992: 74-B: Supp 3; 328.

    Synovial Plica of the Knee:  Fact or Fiction.  DP Johnson,  DM Eastwood,  PJ Witherow.

    In Press;  J. Bone Joint Surg.  [Br] 1992.

    Mapfre Medicinia. 1992: 3: Supl 3: 9-10.

    West of England J. 1992: 7(2); 94.

    The Effect of Lateral Release on Patello-femoral Stability and Wound Viability in Knee Arthroplasty.

    DM Eastwood,  DP Johnson.  J. Bone Joint Surg.  [Br] 1992: 74-B: Supp 3; 327-8.

    Antibiotic Prophylaxis with Cefuroxime in Unilateral and Sequential Bilateral Knee Arthroplasty.

    DP Johnson, ST Donnell.  J. Bone Joint Surg. (Br) 1990; 72B: 166.

    Effect of Continuous Passive Motion on Wound Healing and Joint Mobility after Knee Arthroplasty.

    DP Johnson.  Extracta Orthopaedica. Acron Verlag. Berlin 1991:  13;  131.

    Effect of Continuous Passive Motion on Wound Healing and Joint Mobility after Knee Arthroplasty.

    DP Johnson.  J. Bone Joint Surg. (Br) 1990; 72B: 532.

    Anterior Midline or Medial Parapatellar Incision for Knee Arthroplasty.

    D.P. Johnson.  J. Bone Joint Surg. (Br) 1989; 71B: 886.

    Patellar Subluxation Following Kinematic Knee Arthroplasty.

    D.P. Johnson.  Proceedings of the: 6th Meeting of the European Society of Biomechanics.

    Eds: A. E. Goodship and L. E. Lanyon. Butterworths, London. 1988:  27.

    Continuous Passive Motion Following Knee Arthroplasty. D.P. Johnson.

    Third Congress of the European Society of Knee Surgery and Arthroscopy.

    Abstract Book, Ed-ESKA. RAI Organisatie Bureau, Amsterdam. 1988.

    Transcutaneous Skin Oxygen Tension Analysis of the Viability of Incisions for Knee Arthroplasty.

    Third Congress of the European Society of Knee Surgery and Arthroscopy.

    Abstract Book, Ed-ESKA. RAI Organisatie Bureau, Amsterdam. 1988.

    Patellar Subluxation following Kinematic Knee Arthroplasty. Is the Universal Instrument

    System Universal. D.P. Johnson.

    Bristol Medico Chirurgical J.  1989:  104;  87.

    Patellar Subluxation following Kinematic Knee Arthroplasty. Is the Universal Instrument

    System Universal. D.P. Johnson.

    Third Congress of the European Society of Knee Surgery and Arthroscopy.

    Abstract Book, Ed-ESKA. RAI Organisatie Bureau, Amsterdam. 1988.  54.

    Transcutaneous Skin Oxygen Tension and Viability of Knee Arthroplasty Incisions. D.P. Johnson.

    Third Congress of the European Society of Knee Surgery and Arthroscopy.

    Abstract Book, Ed-ESKA. RAI Organisatie Bureau, Amsterdam. 1988.  57.

    Transcutaneous Skin Oxygen Tension and Viability of Knee Arthroplasty Incisions. D.P. Johnson.

    Journal of Bone and Joint Surgery [Br]. 1988: Vol 70: 497.

    Infection Prophylaxis In Surgery. D.P. Johnson.

    Infectious Diseases Update. Exerpta Medica Asia Ltd. Hong Kong. 1988;  23.

    Antibiotic Prophylaxis With Cefuroxime In Knee Arthroplasty.  D.P. Johnson.

    Journal Of Bone and Joint Surgery [Br]. 1987: Vol 70 : 154.

    Antibiotic Absorption Under Tourniquet. D.P. Johnson, G. C. Bannister, J. Auchincloss and J. Newman.

    Second European Congress Of Knee Surgery And Arthroscopy.  Abstract. Basle, Switzerland. 1986.

    The Outcome of Infected Arthroplasty of the Knee. D.P. Johnson,  G. C. Bannister.

    Second European Congress of Knee Surgery and Arthroscopy.

    Abstracte book.  Springer Verlag.  Basle.  Switzerland.  1986:  57.

    The Outcome of Infected Arthroplasty of the Knee. D.P. Johnson,  G. C. Bannister.

    Bristol Medico Chirurgical J..  1984:  99;  4;  32.

    The Outcome of Infected Arthroplasty of the Knee. D.P. Johnson,  G. C. Bannister.

    J.  Bone  Joint  Surg.  [Br] 1986:  68B;  160.

    Does A Tourniquet Affect Antibiotic Absorption In Knee Replacements.

    G. C. Bannister, J. Auchincloss, J. Newman and D.P. Johnson.

    Journal of Bone and Joint Surgery [Br]. 1986: Vol 68: 160.

  8. POSTER PRESENTATIONS

    Microsurgical Expertise,  Visuo-spatial skills and Dyslexia:  Are They Related?

    SJ Pickering,  SE Gathercole,  DP Johnson. Fourth International Conference of British Dyslexia Association. York. April 1997

    Differential strain in the anterior and posterior fascicles of the patellar tendon: a causative factor in patellar tendonitis? O. Basso,  A.A. Amis ,    D.P. Johnson. E SSKA Rome  May 2002

    Microsurgical Expertise,  Visuo-spatial skills and Dyslexia:  Are They Related?  SJ Pickering,  SE Gathercole,  DP Johnson. Fourth International Conference of British Dyslexia Association. York.April 1997

    Patellar Tendon Anatomy. O. Basso  DP Johnson  A Amis.  Br. Orthop. Research Soc. Oct. 1996.

    The Beneficial Effects of CPM Following Total Knee Arthroplasty.

    DP Johnson,  DM Eastwood.  International Society of the Knee.  Toronto. May 1992.

    The Effect of Lateral Release on Patello-femoral Stability and Wound Viability in Knee Arthroplasty.

    DP Johnson,  DM Eastwood.

    The 9th Combined Orthopaedic Associations Meeting. Toronto.  Canada. July  1992.

    Percutaneous Surgery for Trigger Finger.  DM Eastwood,  DP Johnson.

    The 9th Combined Orthopaedic Associations Meeting. Toronto.  Canada. July  1992.

    Patellar Complications Following Total Knee Arthroplasty.  DP. Johnson,  DM Eastwood.

    The 9th Combined Orthopaedic Associations Meeting. Toronto.  Canada. July  1992.

    A New Surgical Procedure For The Treatment of The Cruciate Deficient degenerative Knee. DP. Johnson,  M. Mansfield.  The 9th Combined Orthopaedic Associations Meeting. Toronto.  Canada. July  1992.

    The Effect of Gentamycin Containing Acrylic Cement on Infection following Knee Arthroplasty.

    DP Johnson,  BA. Coughlan,  T. Wood.

    The 9th Combined Orthopaedic Associations Meeting. Toronto.  Canada. July  1992.

    Synovial Plica of the Knee:  Fact or Fiction.  DP Johnson,  DM Eastwood,  PJ Witherow.

    The International Society of the Knee.  Toronto,  Canada. May  1991.

    Patellar Subluxation Following Kinematic Knee Arthroplasty.

    DP. Johnson.  The Sixth Meeting of the European Society of Biomechanics. Bristol.  Sept 1988.

    Patellar Subluxation Following Kinematic Knee Arthroplasty.  DP Johnson,  DM Eastwood,  PJ Witherow.

    The Third European Congress of Knee Surgery And Arthroscopy. Amsterdam. May 1988.

    The Effect of Lateral Release on Patello-femoral Stability and Wound Viability in Knee Arthroplasty.

    DP. Johnson. The Third European Congress of Knee Surgery And Arthroscopy.  Amsterdam. Holland. May 1988

  9. FACULTY LECTURES BY INVITATION

    Surgical demonstrations, Grand Rounds and daily lectures as Visiting professor

    Riyadh Military Hospital Department of Orthopaedics, Riyadh, Saudi Arabia, April 2007

    The Principles of Total Knee Replacement.

    Minimally Invasive Total Knee Replacement..

    Garmish, Germany, March 2007

    Patellar resurfacing and complications.

    Minimally Invasive TKA.

    Lustrum Congress, Dutch Orthopaedic Trainee Association, Noordwijk. Oct 2007

    Advances in Knee Surgery: Minimally Invasive Surgery Instructional Course: lecturer, Instructor and surgical demonstrator.

    University of Munster, Germany. Feb 2006

    Combined German Orthopaedic Forum, Munster, Germany March 2006

    University of Barcelona. Spain April 2006

    University of Barcelona. Spain Feb 2005

    University of Utrecht, Netherlands, May 2005

    University of Munster, Germany. Nov 2005

    Live Surgical Demonstration and Visiting professor:

    University Hospital, Sosnowiec, Krakow, Poland. Professor Gazdzik.. Oct 2005

    Controversies in Knee Surgery Locking Castle Medical Centre,  WSM Bristol. March 2005

    An Update on Knee Injuries.  Football Association Regional Medical Association, Bristol March 2005

    The National Football Association Medical Conference. The Football Association. Harrogate. May 2004

    New Technology in Total Knee Replacement Progressive Concepts Course. UZ Leuven, Belgium Nov 2003

    Is there a Place for Surgery in Patellar Tendonitis? Controversies in Knee Surgery. London.  June 2003

    University of Zurich. W Muller Anniversary 3rd International Instructional Course in Knee Surgery

    Basle. Switzerland.Jan. 2003

    The 6th Wexam Park Cruciate Ligament Meeting, Wexam Park, Berkshire, UK  Nov 2002

    European Society of Sports Injury Arthroscopy and Knee Surgery. Rome Apr 2002

    Patellar Tendonitis, Anatomical Study and MRI investigation.

    Patellar Tendonitis Investigation, Operative and Non-operative Management.

    Patello-femoral Complications after Total Knee Replacement

    Sports Medicine Symposium. Arcus SportKlinik. Pforzheim. Germany. Nov. 2000

    The Use of Bio-absorpable Screws in ACL Reconstruction.

    The Fifth Wexam Park Cruciate Meeting. Slough. Nov. 2000

    Patellar Tendonitis Operative Management. Surgical  Techniques in Revision ACL Reconstruction.

    Nottingham International Knee Congress. Nottingham. Oct. 2000

    Surgical Approaches to the Knee.   DP Johnson WE Muller N Freiderick

    European Society of Sports Injury, Arthroscopy and Knee Surgery. London Oct. 2000

    Arthroscopic Surgery for Patellar Tendonitis.  The Belgium Orthopaedic Association Annual Meeting. Brussels. Mar.  1999.

    Bio-absorpable Screws in ACL Reconstruction. The Fourth Wexam Park Cruciate Meeting. Slough. Nov. 1998

    Synovial Plica,  Patellar tendonitis and Anterior Knee Pain. Crewe Weekend Teaching Programme.  Oswestry. Sept.  1998

    Sports Medicine and Knee Surgery in the year 2000. Sports Medicine in the year 2000.  Patterswolde International Symposium. University of Gronigen.  Netherlands.  April 1998

    ACL reconstruction with Bioabsorpable Screw Fixation.

    Third East Berkshire Anterior Cruciate Ligament Symposium. Nov.  1998

    Anterior Cruciate Reconstruction Using Patellar Tendon Advanced Arthroscopic Techniques. Bristol. June.  1998

    Anatomy of the Patellar Tendon and Harvesting of the Bone Patellar tendon Bone Graft.

    The Nottingham Knee Symposium Oct.   1997

    ACL Ligament Reconstruction in the Over Fourties. The Nottingham Knee Symposium Oct.   1997

    Anterior  Knee Pain.  Regional  Specialist Trainee Orthopaedic Instructional Course. Sheffield. Dec  1996

    Arthroscopic Surgery for Patellar Tendonitis.

    A.C.L. Reconstruction in the Over 40 years Age Group.

    Third East Berkshire Anterior Cruciate Ligament Symposium. Nov.  1996

    The Nottingham Knee Symposium Oct.   1997

    Tricks and Pitfalls of Arthroscopic Anterior Cruciate Ligament Reconstruction.

    Discoid and Difficult Menisectomy.

    Advanced Arthroscopy Instructional Course.  Royal National Orthopaedic Hosp. Nov.  1996

    The use of Bioabsorbable Screws for A.C.L. Reconstruction.

    Patellar  Tendonitis:  Anatomy,  Pathogenesis,  Investigation and Treatment.

    2nd  Basel International Knee Surgery Congress.  Switzerland. Sept. 1996

    Third East Berkshire Anterior Cruciate Ligament Symposium. Nov.  1996

    The Nottingham Knee Symposium Oct.   1997

    Anterior Knee Pain.

    RCSEd and the Football Association International Meeting.  Lilleshall. July 1996

    SW Regional FA Medical Society. Bristol City. Oct  1996

    Postgraduate Orthopaedic Training Course. University of Sheffield Dec  1996

    Injuries of the Knee.  Diagnosis and Management.

    Brirish Association of Sports Medicine.  Lilleshall.  Nov. 1995 July 1995.July 1996

    Patellar Tendonitis:  Anatomy,  Biomechanics,  Histology and Surgical Treatment.

    British Orthopaedic Sports Trauma Association.  Royal College of Surgeons. April  1996

    Difficult Menisectomy and Discoid Meniscus Resection.

    Basic MATU Arthroscopy Instructional Course.  Royal National Orthopaedic Hosp. Jan.  1996

    Surgical complications of Arthroscopic Anterior Cruciate Ligament Reconstruction.

    Advanced MATU Arthroscopy Instructional Course.  Royal National Orthopaedic Hosp. Jan.  1996

    Patello-femoral Complications in Knee Arthroplasty. First Satellite Symposium.  Tutlingham.  Germany. Nov.  1995.

    Instrumentation for Arthroscopy.

    Tricks and Pitfalls in Arthroscopy. Nov 1996

    Basic MATU Arthroscopy Instructional Course.  Royal Coll. of Surg. Nov.  1995

    The Degenerate Unstable Knee. ESSKA symposium at the EFORT meeting Munich.  July 1995.

    Disorders of the Patello-femoral Joint. Management of Sports Injuries Royal College of Surgeons London.   April 1995.

    Pitfalls in the Technique of Arthroscopic Anterior  Cruciate Ligament  Reconstruction.

    Arthroscopic  Anterior  Cruciate Ligament  Replacement  Course.  Nottingham.   Oct. 1994.

    Rehabilitation following arthroscopic ACL reconstruction.

    Arthroscopic  Anterior  Cruciate Ligament  Replacement  Course.  Nottingham.  Oct. 1994.

    The Management of Knee Injuries.

    BASM Advanced Instructional Course,  Lilleshall.  Nov.  1994.  July 1995.  Nov. 1995.

    The Anterior Cruciate Ligament  Instructional ACL Course.  Nottingham.  Sept.  1994.

    The Post-op Stiff Knee. The Nottingham International Knee Symposium.   Nottingham. Sept.  1994.

    Radiological and MRI Analysis of the Morphology of Patellar Tendonitis.

    AOSSM – ESSKA Fellowship Meeting. Stanmore.  London  May  1994.

    The 1993 ESSKA – AOSSM Sports Medicine Travelling Fellowship.

    AOSSM – ESSKA Fellowship Meeting. Stanmore.  London  May  1994.

    The Ideal Travelling Fellow. European Society for Knee Surgery and Arthroscopy.  ESSKA Congress.  Berlin. June 1994.

    Anterior Knee Pain.

    Royal Society of Medicine – British Orthopaedic Sports Trauma Association,  London  1994.

    BASM Advanced Injury Course.  Wroughton  1994.

    Assessment of the Shoulder. BASM Intermediate Course.  Lilleshall Hall.  National Sports Injury Centre.  Nov 1993.

    Investigation and Infiltration of the Upper Limb. BASM Advanced Instructional Course.  Wroughton 1993,  1994.

    Synovial Plicae Fact or Fiction.

    Hospital For Special Surgery,  New York.

    Cleveland Clinic,  Ohio.

    University of Pittsburgh,  Pennsylvania.

    Duke University,  Durham, N. Carolina.

    Hughston Orthopaedic Clinic, Columbus Georgia.

    American Sports Medicine Institute, Birmingham, Alabama. July  1993

    The Biomechanics of Wound Healing Following Knee Arthroplasty.

    The Orthopaedic Speciality Hosp., Salt Lake City.

    Kerland-Jobe Orthopaedic Clinic, Los Angeles.  July  1993

    The Role of MRI in the Assessment of Sports Injuries. The Kerland Clinic. July  1993

    Arthroscopic Debridement for Early Arthritis. The Nottingham International Knee Symposium.   Nottingham  Nov.  1993.

    The Prevention and Rehabilitation of Knee Injuries.  Sports Council.  Taunton 1993.

    Knee Injury:  The Multi-disciplinary Approach.  Sports Council.  Taunton  1993.

    The Knee:  Injury Arthritis and Rehabilitation.  The Postgraduate Society.  Bristol  1993.

    The Unstable Degenerative Knee. The Nottingham International Knee Symposium.   Nottingham  1992.

    Advances In Joint Replacement. Post-Graduate program of Bristol Area General Practitioners.  Bristol 1992.

    Knee Injuries.  South Bristol Medical Society.  Bristol 1992.

    New Techniques In Arthroscopy.  Robert Jones and Agnes Hunt Orthopaedic Hospital.  Oswestry  1991.

    The Unstable Degenerative Knee. Sports Related Injuries.  Royal Postgraduate Medical School.  London  1991.

    Anterior Knee Pain In Athletes. Management of Sports Injuries.  The Hunterian Institute.  Royal College of Surgeons.  1991.

    Anterior Knee Pain In Athletes. South West Society of Chartered Physiotherapists.  Cheltenham  1991.

    Automobile Associated Knee Injuries. Motor Accident Solicitors Society.  Nottingham  1991.

    Arthroscopy of the Shoulder. Second Advanced Course on Arthroscopic Surgery.  Droitwich Knee Clinic. Worcester.  1991.

    Soft Tissue Injury of the Neck. The Third International Conference on Sports Injuries.  Lilleshall Hall.  Shropshire  1991.

    Sports Medicine in Australia. The Third International Conference on Sports Injuries.  Lilleshall Hall.  Shropshire  1991.

    The Diagnosis and Management of Knee Injuries.  University of Fiji.  Suva, Fiji  1990.

    Continuous Passive Motion In Knee Arthroplasty.  The Nottingham Knee Symposium. 1989

    Patellar Complications and Reconstruction Following Knee Arthroplasty.

    The Nottingham Knee Symposium.   Nottingham  1989.

    The role of CPM in Knee Replacement. Univ Oslo.   Norway  1988.

    The role of CPM in Knee Replacement. Univ Gottenberg.  Sweden  1988.

    Infection following Knee replacement.  Infection In Orthopaedics.   Bristol  1988.

    The Growth Plate: Anatomy, Physiology and Injury Patterns. The Nottingham Fracture Forum.  Nottingham  1988.

    Continuous Passive Motion Following Knee Arthroplasty. Recent Advances in the Surgery of Arthritis.  London 1988.

    The Use of CPM in Knee Replacement. Controversies in the Surgery of Arthritis.  Bristol  1988.

    Specialised techniques in knee replacement.  Chulalongkorn University.   Bangkok  1987.

    Current Management of Polytrauma.  Universiti Kebangsaan Malaysia.  Kuala Lumpur  1987.

    Antibiotic Prophylaxis in Surgery, Orthopaedics and the Knee.

    The Malaysian Society of Infectious Diseases and Chemotherapy.  Kuala Lumpur  1987.

    The Use of CPM in Knee Arthroplasty. The role of CPM in the Preservation of Joint Function. First National Symposium, London 1987.

  10. LEARNED SOCIETY FACULTY and MEETING CHAIRMAN

    Combined German Orthopaedic Forum, Munster, Germany , March 2006

    European Society of Sports Injury, Arthroscopy and Knee Surgery. Rome, April 2002

    European Society of Sports Injury, Arthroscopy and Knee Surgery. London , Oct. 2000

    World Congress On Orthopaedic Sports Trauma. Western Pacific orthopaedic Association. Asia pacific Orthopaedic Society. Brisbane. Australia. April 2000

    European Federation of Orthopaedics and Traumatology. ESSKA. Speciality Session.  Munich. July.  1995.

    European Society of Knee Surgery and Arthroscopy.  Berlin. April.  1994.

  11. PRESENTATIONS TO LEARNED SOCIETIES. (not listed elsewhere)

    ACL study group meeting Cape Town  Jan 2014

    Minimally Invasive Techniques for Knee Arthroplasty.

    Combined German Orthopaedic Forum, Munster, Germany  March 2006

    15th Annual International Course on Sports Injuries

    Royal College of Surgeons of Edinburgh and the Football Association.  Daventry, July 2004

    Current Concepts in Knee Arthroplasty Course

    Pellenberg, Belgium. Nov 2003

    International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine.

    Aukland, NZ. March 2003.

    University of Zurich. W Muller Anniversary 3rd International Instructional Course in Knee Surgery

    Basle. Switzerland. Jan. 2003

    The 6th Wexam Park Cruciate Ligament Meeting, Wexam Park, Berkshire, UK Nov 2002

    British Orthopaedic Association. Cardiff. Sept 2002

    Am Orthopaedic Society for Sports Medicine, Orlando, USA July 2002

    European Society for Knee Surgery, Arthroscopy and Sports Medicine. Rome April 2002

    The ACL Study Group, Montana, USA,March 2002

    Sports Medicine Symposium. Arcus SportKlinik. Pforzheim. Germany. Nov. 2000
    The Fifth Wexam Park Cruciate Meeting. Slough. Nov. 2000

    European Society of Sports Injury, Arthroscopy and Knee Surgery. London Oct. 2000

    Nottingham International Knee Congress. Nottingham. Oct. 2000

    World Congress On Orthopaedic Sports Trauma. Brisbane. Australia. April 2000
    The Magellan Society. Brisbane. Australia. April 2000

    The Belgium Orthopaedic Association Annual Meeting. Brussels.Mar.  1999.

    The Fourth Wexam Park Cruciate Meeting. Slough. Nov. 1998

    Crewe Weekend Teaching Programme.  Oswestry. Sept.  1998

    The British Association of Knee Surgery. Bristol. Mar.  1999

    The Patello – femoral Study Group. Lyon. France. Oct. 1998

    British Orthopaedic Sports Trauma Association.  Harrogate. Mar.  1997

    The British Association of Knee Surgery. Harrogate. Mar.  1997

    British orthopaedic Research Society.  Brighton.  Mr. O. Basso Sept 1996

    Am. Orth. Soc. Sports Med.  Orlando. June 1996

    ESSKA congress.  Budapest. May  1996

    A.C.L.  Study Group.  Nevis. May  1996

    British Orthopaedic Association.  Llandudno. April  1996

    British Orthopaedic Sports Trauma Association.  Royal College of Surgeons. April  1996

    European Federation of National Ass of Orthop & Trauma.  Barcelona March 1996

    European Federation of National Ass of Orthop & Trauma.  Munich July  1995

    The Magellan Society.  Stockholm,  Sweeden.   June  1995

    The British Association of Knee Surgery. Manchester.Nov.  1994.

    The South West Orthopaedic Association.  Bristol. Oct.  1994.

    The Nottingham International Knee Symposium.  Nottingham. Sept. 1994.

    The European Society of knee Surgery and Arthroscopy.  Berlin. April.  1994.

    The British Orthopaedic Sports Trauma Association.  London. April.  1994.

    The AOSSM – ESSKA Travelling Fellows. London. April  1994.

    The Nottingham International Knee Symposium.  Nottingham. Sept.  1993.

    The International Arthroscopy Association.  Copenhagen. Denmark. June  1993.

    Prevention and Rehabilitation of Injury.  Sports Council.  Taunton. March 1993.

    The South West General Practitioners Association.  Bristol. Feb. 1993.

    The Postgraduate Society.  Bristol. Sept. 1992.

    The 9th Combined Orthopaedic Associations Meeting.  Toronto.  Canada. July  1992.

    The South West Orthopaedic Club. Bath. UK. May  1992.

    The First World Congress of Sports Trauma.  Palma de Mallorja.  Spain. May  1992.

    American Academy of Orthopaedic Surgeons. Washington DC.  USA. Feb.  1992.

    British Association Of Knee Surgery.  British Orthopaedic Association.  Cambridge. Sept.  1991.

    Sports Related Injuries. Royal Postgraduate Medical School.  London. July   1991.

    The Second Advanced Course in Practical Arthroscopy.  The Droitwich Knee Clinic. June  1991.

    British Society of Children’s Orthopaedic Surgery. Newcastle. June  1991.

    The Third International Conference on Sports Injury.

    International Sports Medicine Centre.  Lilleshall Hall.  Shropshire. June  1991.

    The International Society of the Knee. Toronto,  Canada. May  1991.

    The International Arthroscopy Association. Toronto,  Canada. May  1991.

    The Australian Knee Surgery Association. Sanctuary Cove, Australia. Sept. 1990.

    The Fijian Postgraduate Surgery Association. Suva, Fiji. Aug. 1990.

    The International Nottingham Knee Symposium. Nottingham.  Sept. 1989.

    The British Orthopaedic Association and the

    Italian Orthopaedic Association Meeting. London. Sept. 1989.

    Combined British Orthopaedic Association and the

    Hellenic orthopaedic Association Meeting. Rhodes. Greece.  May  1989.

    British Association for Surgery to the Knee. London. Feb.  1989.

    British Association for Surgery to the Knee. Oxford.  Sept.  1988.

    The Sixth Meeting of the European Society of Biomechanics. Bristol.  Sept.  1988.

    Controversies in the Surgery of Arthritis. Bristol. June  1988.

    The Nottingham Fracture Forum. Nottingham. June  1988.

    The Third European Congress of Knee Surgery And Arthroscopy.  Amsterdam. Holland.  May  1988.

    The South West Orthopaedic Club. Truro. Apr.  1988.

    Chulalongkorn University. Bangkok, Thailand. Nov. 1987.

    Universiti Kebangsaan Malaysia. Kuala Lumpur, Malaysia. Nov. 1987.

    The Malaysian Society of Infectious Diseases and Chemotherapy.

    Kuala Lumpur, Malaysia. Nov. 1987.

    The Inaugural Congress Knee Section Western Pacific Orthopaedic Association.

    Penang, Malaysia.Nov. 1987

    The 7th Congress of the ASEAN Orthopaedic Association. Penang, Malaysia.  Nov. 1987.

    The Role Of Continuous Passive Motion In The Preservation Of

    Joint Function. First National Symposium. Royal National Orthopaedic Hosp, Stanmore.Nov. 1987.

    British Orthopaedic Research Society. London. Sept. 1987.

    A.B.C. Travelling Fellows. Bristol. May 1987.

    British Orthopaedic Research Society. Durham.  Apr. 1987.

    Musculo-Skeletal Research Society. University of Bristol. Bristol.  Feb. 1987.

    Royal Society Of Medicine. London.  Feb. 1987.

    The Second European Congress of Knee Surgery And Arthroscopy.

    Basle, Switzerland. Nov. 1986.

    The British Orthopaedic Association. Llandudno. Apr. 1985.

    The Rheumatoid Arthritis Surgical Society. Bristol. Dec. 1984.

    The South West Orthopaedic Club. Plymouth. May 1984.

    The First European Congress Of Knee Surgery And Arthroscopy.  Berlin, Germany.  Apr. 1984.

    Gastroenterology Meeting. University of California, San Francisco.  Sept. 1979.

    INSTRUCTIONAL COURSES ATTENDED (not listed elsewhere)

    British Orthopaedic Association  annual meeting 2013, 2014

    Infection Update, Taunton Sept 2014

    ACL study group meeting Cape Town  Jan 2014

    British Association of Surgery of the Knee 2013, 2014

    Controversies in Hip Surgery Bristol 2013, 2014

    ACL Study Group, Jackson Hole Feb 2012, Phucket Thailand Feb 2010, Rhodes May 2000, Beaver Creek 2006, New Orleans 2004, ,  Ishgyl,

    Controversies in Hip Replacement, Bristol, Nov 2008,2009, 2010 Nov 2011

    Novocart Articular Cartilage Reconstruction Course RCS Eng June 2011

    Austria., March 1994.

    AOSSM annual Congress. Orlando. USA July 2002, July 2009, Sun Valley Idaho.  July  1993

    New techniques in Knee Surgery 2005/6 Barcelona, Munster and Utrecht.

    Controversies in Hip ReplacementNov 04, 05, 06, 07, 08, Nov 2009 Bristol UK.

    British Orthopaedic Association,. Sept. 1998, 2001, 02, 03, 04, 05, 06, 07,08, 09

    International Knee Arthroplasty Course, Bruges, Belgium  June 2004

    Current Concepts in Knee Arthroplasty Course, Pellenberg, Belgium. Nov 2003

    3rd International Instructional Course. Basel. Switzerland ,  Feb 2003

    Debates about Hip Replacement, Bristol. Nov 2002

    Ligament Balancing in Total Knee Replacement. The Orthopaedic Centre. St Louis Missouri. USA. Nov 2001

    Knee Arthroplasty Update. Geneva. Switzerland,  May 2001

    International Society of Arthroscopy, Knee Surgery, Orthopaedic Sports Medicine. ISAKOS.

    Montreau, Switzerland. May 2001

    Controversies in Knee Surgery. London.  Sept 2001

    European Society of Sports Medicine, Knee Surgery and Arthroscopy.London. Sept. 2000

    The Fouth Wexam Park Cruciate Meeting Nov  2000

    British Association of the knee, 98, 2001, 02, 03, 04, 05, 06, 07,08, 09

    Osteotomies around the Knee.  Bristol.  Mar.   1998

    American Academy of Orthopaedics. New Orleans, Mar.   1998. San Francisco.  Mar.   1997

    Alpine Medical Ski Club.  Blue River,  British Colombia.  Mar.   1997

    Sports Medicine 2000.  Stockholm. June.  1995.

    American Orthopaedic Society for Sports Medicine, Sun Valley Idaho. July  1993

    Controversies in Knee Surgery. Royal Society of Medicine. May  1993.

    Orthopaedics and Sport.  Harrogate March 1993.

    The European Society of Knee Surgery, Arthroscopy and Sports. Palma. May 1992.

    The International Knee Society, International Arthroscopy Ass. Toronto Feb. 1992.

    The American Academy of Orthopaedic Surgeons. Washington. USA. March 1992.

    The International Nottingham Knee Symposium. Nottingham. Sept. 1991,

    Update on Joint Replacement. Sydney. Sept. 1990.

    The Bone Cement Interface. Guildford.  May 1989.

    The International Nottingham Knee Symposium. Nottingham. Sept. 1989.

    Surgery of the Young Hip. Bristol. June 1989.

    Recent Advances in Joint Arthroplasty. London. Sept.  1988.

    The Nottingham Fracture Forum. Nottingham.  June  1988.

    Controversies in the Surgery of Arthritis. Bristol.  June  1988.

    Advances in Orthopaedics. Bristol.  Aug.  1986.

    Advanced Operative Arthroscopy.  E.S.K.A. Basle, Switzerland.  Sept.  1986.

    Advanced ASIF/AO Course. Davos, Switzerland.  Dec.  1985.

    Micro surgical Anastomosis Workshop. Oxford.  Aug. 1985.

    Hoffman External Fixation Course. Bristol.  Nov. 1985.

    10th Annual ASIF/AO Course [Basic]. Oswestry.  May  1985.

    Whipps Cross Surgical Course. London.  Sept. 1984.

    Bone Tumour Course. Bristol.  July  1983.