The purpose of this study was to assess whether there was significant variation in distal femoral morphology between individuals. In the first part of this study we analysed the distal femoral morphology of 100 consecutive patients undergoing routine total knee replacement for osteoarthritis. In the second part we reviewed the morphology of 50 cadaveric distal femoral specimens without osteoarthritis. There was considerable variability in distal femoral morphology.

Our findings suggest that: 1, use of the posterior condylar axis for femoral component alignment should be used cautiously; 2, problems in balancing flexion and extension gaps on both sides of the knee can be predicted; 3, a greater range of femoral component shapes should be available.

Introduction: The Motus (Osteo) total knee replacement design is an uncemented, stemless, hydroxyapatite-coated prosthesis designed as a low profile resurfacing implant.

Aim: To review the results after five to eight years of the use of this prosthesis by one surgeon and to discuss the perceived advantages of its design.

Methods: Between 1992 and 1996 the Motus (Osteo) prosthesis was used in 606 primary total knee replacements in 409 patients. The evaluation was undertaken using a clinical knee score based on the Knee Society Score and the Hospital for Special Surgery (HSS) score, which produces a maximum score of 200/200.

Results: The mean age was 69 years (range: 31 to 88 years) with 53% of the patients being female. Osteoarthritis was the underlying pathology in the majority of the cases. The minimum time to follow up was 60 months (mean: 79, range: 60 to 104 months). The mean pre-operative knee score was 98/200 with a range of movement from six degrees to 122 degrees. After five years, the mean knee score was 180/200 with a range of movement from one degree to 113 degrees. To date only two patients have required a revision procedure, both for deep infection. Twenty-six patients have died and six have been lost to follow-up as they are overseas.

Conclusion: At a minimum five-year review, the Motus (Osteo) total knee replacement prosthesis produced excellent functional and clinical results with a low rate of complications.

Introduction: Dysfunction of the patellofemoral mechanism presents as patella dislocation or subluxation with or without anterior knee pain. Causes are numerous and include ligamentous deficiency, muscular deficiency, anomlies of bony alignment and patellofemoral joint abnormalities. The 130 different procedures described to treat this condition reflect the multiple pathologies responsible. No single procedure has gained widespread acceptance. We present a surgical technique that attempts to correct as many of these deficiencies of the patellofemoral mechanism as possible.

Method: The procedure consists of a lateral release, a vastus medialis tendon advancement and a tibial tubercle osteotomy. The ‘Q’ angle is corrected by medialisation of the tubercle, patella alta is corrected by a distalisation technique and joint reaction forces through the patellofemoral joint are reduced by placing the tibial tuberosity in a more anterior position.

100 patients who have undergone this procedure have been identified. 81 percent initially presented with patella subluxation or dislocation. The remainder complained of anterior knee pain with evidence of abnormal patella tracking on examination. 52 percent of our patients had undergone at least one previous patellofemoral realignment procedure which had failed. 43 percent of the patients had generalised ligamentous laxity.

Results: The mean follow-up was 2.6 years from the index operation. 81 percent of the patients stated the operation had improved or abolished their symptoms. Generalised ligamentous laxity was present in the remaining 19 percent and seemed to correlate with a poor outcome. 66 percent of patients stated they were satisfied with the outcome of the surgery. Two patients developed recurrent subluxation after surgery and one of these has undergone a revision distal realignment procedure.

Using the functional category described by Crosby and Insall for patellofemoral symptoms 66 percent had a good-to-excellent outcome, 23 percent had a fair outcome and 10 percent of the patients stated they were worse following the procedure with increased anterior knee pain. 100 percent of these patients had grade 3 or 4 cartilage defects on retropatella surface. 57% of patients returned to sporting activity. 14% of the remainder had not returned to sporting activity because of persisting symptoms in the knee.

57 percent of patients had lost a mean 12.5 degrees of flexion of the knee at follow-up [range 5–30]. 5 percent of patients developed minor complications following surgery. No radiological deterioration was seen in any patients although coexistent patellofemoral osteoarthritis was seen in 25 percent of patients. There was no loss of fixation in any of the patients.

Discussion: A multifaceted approach to the complex problem of patellofemoral dysfunction appears to achieve satisfactory functional results in patients even when previous surgical realignment has failed. The procedure appears to be associated with low morbidity although a loss of flexion of the knee is to be expected. Generalised ligamentous laxity and cartilage defects on the retropatella surface appear to be associated with poor results and anterior knee pain in the absence of instability may be a cause for persisting symptoms.