Purpose of Study:

To describe the degree and type of disability experience by patients with combined postero-lateral corner and posterior cruciate ligament knee injuries

Methods and Results: After rigorous exclusion criteria were instituted twelve patients were identified as having the required combined knee ligament injuries. These patients underwent functional assessment, clinic examination and gait analysis at the Oxford Gait Laboratory.

Significant functional disability was noted in all patients. Characteristic gait abnormalities identified included hyperextension and dynamic varus deformity with a corresponding increase in the internal valgus knee moment. Electromyographic data revealed early and prolonged contraction of the medial hamstrings and gastrocnemius muscles.

Conclusion: These results suggest the presence of compensatory mechanisms of the musculature around the knee and suggest direction in rehabilitation programs in patients with combined injuries to the posterior cruciate ligament and posterolateral corner of the knee. The results also provide baseline data that will be useful when evaluating the post-operative outcomes in patients undergoing knee ligament reconstruction in the future.

Purpose of study The purpose of this study was to present the anterior femoral cortical line (AFCL) as a new anatomical landmark to aid the assessment of intra-operative femoral component rotation. The AFCL was compared with an established axis (the anteroposterior (AP) axis or Whiteside’s line) in both a cadaveric and clinical study.

Methods Two points indicating the AP axis were identified and marked on 50 normal cadaveric femora. The AFCL was identified and marked with a rigid wire secured on the surface and the distal femur was photographed. A perpendicular to the AP axis was drawn on each image and the angle between this line and the AFCL was measured.

68 consecutive patients undergoing total knee arthroplasty for osteoarthritis of the knee were included in the clinical part of the study. After a routine exposure the AP axis was marked on each distal femur. The AFCL was identified and the anterior cortical cut was made parallel to this line. The angle between this cortical cut and the perpendicular to the AP axis was measured with a sterile goniometer.

Results In the cadaveric study the AFCL was a mean 7.0 degrees internally rotated to the AP axis (SD = 5.1 degrees). In the clinical study in 8 patients it was impossible to draw the AP axis because of dysplasia or destruction of the trochlea by osteoarthrosis. In the remainder the mean difference between the anterior femoral cortical line and the AP axis was 1.5 degrees internally rotated (SD = 1.9 degrees) .

Conclusion The anterior femoral cortical line has been shown in this study to be a useful clinical axis for assessing rotation of the femoral component and is without some of the disadvantages associated with other landmarks.

The purpose of study was to investigate kneeling ability after total knee replacement.

100 patients who were at least one year following routine uncemented primary total knee replacement were identified.

32% of patients stated they were able to kneel without significant discomfort. 64 (64%) of patients were actually able to demonstrate kneeling ability without pain or discomfort or with mild discomfort only. 24 (24%) of patients were therefore unable to demonstrate the ability to kneel because of discomfort in the knee.

There was no difference in the “kneelers” and “non-kneelers” with regard to overall knee score, range of motion and the presence of patella resurfacing.

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.

We have investigated the ability to kneel after total knee replacement. We asked 75 patients (100 knees) at least six months after routine uncemented primary total knee replacement, to comment on and to demonstrate their ability to kneel. Differences between the perceived and actual ability to kneel were noted. In 32 knees patients stated that they could kneel without significant discomfort. In 54 knees patients avoided kneeling because of uncertainties or recommendations from third parties (doctors, nursing staff, friends, etc). A total of 64 patients was actually able to kneel without discomfort or with mild discomfort only and 12 of the remainder were unable to kneel because of problems which were not related to the knee. Twenty-four patients therefore were unable to kneel because of discomfort in the knee.

There was no difference between the ‘kneelers’ and ‘non-kneelers’ with regard to overall knee score, range of movement and the presence of patellar resurfacing.

We analysed the histological findings in 1146 osteoarthritic femoral heads which would have been considered suitable for bone-bank donation to determine whether pathological lesions, other than osteoarthritis, were present. We found that 91 femoral heads (8%) showed evidence of disease. The most common conditions noted were chondrocalcinosis (63 cases), avascular necrosis (13), osteomas (6) and malignant tumours (one case of low-grade chondrosarcoma and two of well-differentiated lymphocytic lymphoma). There were two with metabolic bone disease (Paget’s disease and hyperparathyroid bone disease) and four with inflammatory (rheumatoid-like) arthritis.

Our findings indicate that occult pathological conditions are common and it is recommended that histological examination of this regularly used source of bone allograft should be included as part of the screening protocol for bone-bank collection.