Abstract
Introduction
The variability of the endosteal geometry after removal of the femoral component can make proximal fit difficult to achieve with an ‘off the shelf’ prosthesis. Whatever the anatomy of the proximal femur, it is important to achieve immediate stability, preserve bone stock and protect the femur from cortical defects which can lead to subsequent fracture. In revision Total Hip Arthroplasty (THA) this requires a large inventory of modular components. The use of custom computer-assisted design-computer-assisted manufacture (CAD-CAM) components negates this need. Little has been published on the use of custom-made components in revision THA. We report the results of a cohort of patients who underwent revision THA using CAD-CAM femoral components.
Methods
A prospective study was performed between 1991 and 1998. A consecutive series of patients who had revision THA using custom components were assessed clinically and radiologically. The design of the femoral components was governed by the existing femoral bone stock. Patients were reviewed pre operatively then at 6 weeks, 3months and 12 months postoperatively and then annually. Radiographs were assessed at each visit and Oxford, Harris and WOMAC hip scores were calculated
Results
One hundred and fifty eight patients were included (97 males, 61 females). Mean age was 63.1 years (34.6 to 85.9 years). Mean follow-up was 10.8 years (10 to 12).
The mean Oxford, Harris and Western Ontario and McMaster hip scores improved from 41.1, 44.2 and 52.4 pre-operatively to 18.2, 89.3 and 12.3, respectively (p < 0.0001 for each). Six patients required further surgery. Survival of the femoral component was 97% (95% confidence interval 94.5 to 99.7).
Conclusion
Custom CAD CAM femoral components provide pain relief and return to function when used in revision THA. These clinical results are comparable to previously published reports for revision THA using either cemented or uncemented components.
