Introduction: Bone fragility is a result of the reduction in bone mineral density and mass. This reduction directly reduces the effectiveness of trabecular cross bracing. The problem of femoral neck fractures after hip resurfacing surgery is directly related to the mechanical load on the osteoporotic bone.

Aim: To determine any correlation between the degree of osteoporous and subsequent femoral neck fractures.

Methods: A comparison was made between both femoral necks in the same patient, to determine the degree of osteoporosis prior to surgery. These results were then compared with subsequent changes in osteoporosis 12 months post-operatively.

Bone mineral density values, were used to compare the non-operative femoral neck to the operative femoral neck before surgery. These values were then used as a predictive risk of subsequent femoral neck fracture in this patient group. Bone mineral density assessments were repeated 12 months after the surgery to compare the subsequent changes in the osteoporotic values. The bone mineral density evaluations were carried out on one hundred patients, both male and female between the ages of 28 and 87 years. The criterion for entry into this group was a bone mineral density value of no lower than 1.5 standard deviation points below the young reference value.

Results: We found an improvement in the bone mineral density values for each patient, therefore reducing the risks of subsequent femoral neck fracture.

Aim: To assess the survival rate of implants and the effect of UKR on knee pain, function, stiffness and quality of life in a prospective study.

Methods: All of the knee replacements were performed using minimally invasive techniques. SF36 and WOMAC were evaluated pre-operatively and at six-monthly intervals post-operatively.

Results: There were 506 knees. The mean post-operative evaluation time was two years and six months and the maximum time was three years and nine months. The status of all knees was established. There were nine failures as determined by the need for revision procedures. Six patients died with their implants functioning.

Survival analysis: 99% at 12 months 98% at 24 months 98% at 36 months.

The scores on SF36 and WOMAC were adjusted to the Australian Population Norm. The WOMAC score showed an increase in function, and a decrease in the pain and stiffness scores. The physical and mental component summaries of the SF-36 both indicated an increased quality of life post-operatively. Implant failure was due to loosening of tibial and femoral components and progression of arthritic changes in the lateral compartments.

Conclusion: The results from the health assessment forms indicated a high patient satisfaction with the operation and a sustained improvement in quality of life, flexibility and function.

Introduction: Medial unicompartmental knee replacement (UKR) is a successful procedure in the management of early osteoarthrosis. This procedure is not usually indicated in patients who have insufficiency of the anterior cruciate ligament (ACL). However, a problem arises when, after a UKR, an ACL rupture occurs, and instability develops. A technique is described to stabilise the knee and possibly avoid conversion to total knee replacement.

Methods: Three patients underwent arthroscopic ACL reconstruction. Only semitendinosus tendon was used. The proximal fixation was with a Mulch screw (Biomet) and the distal fixation was with two screws and washers. A post-operative, standard, accelerated rehabilitation programme was used in all three.

Results: After two years, two patients continued playing doubles tennis, and one continued as a dancing instructor.

Conclusions: While an ACL-related instability is a contraindication to undertaking a UKR, the disruption of an ACL in a well functioning UKR and the development of instability need not necessarily force the conversion to TKR. Using a modified hamstring reconstruction it was possible to stabilise the knee and maintain the UKR function.