PROXIMAL IMPACTION BONE GRAFTING IN REVISION HIP SURGERY.

Abstract

Significant proximal femoral bone deficiency in revision hip surgery poses a considerable challenge, especially as revision hip surgery is increasing in prevalence. Many femoral prosthetic devices, which compensate for this bone loss, are available to surgeons but ideally one wants to restore viable proximal bone stock. The Oxford Universal Hip (OUH) has been designed and modified with these challenges in mind. This is atrimodular, non-locking device that allows for some rotation and subsidence in the cement. Load transfer occurs at the proximal wedge, thus avoiding proximal stress shielding. The OUH has been used extensively in both primary and revision hip surgery and is particularly useful when used in conjunction with proximal impaction bone grafting. The main aim of this study was to determine the clinical outcome of the patients. The viability and survivorship of the impacted bone graft was assessed in order to give some indication of adequate perfusion of the incorporated bone grafting.

Between 1999 and 2002 the OUH, in combination with proximal impaction bone grafting, was implanted in 72 hip revisions in 69 patients. All patients were clinically evaluated using the Oxford Hip score. Histological samples of impacted bone grafting were analysed by a pathologist 2 years after implantation to assess viability and perfusion of the impacted bone graft.

The Oxford Hip Score improved from a pre-operative to a post-operative score of 45 (26–58) to 24.3 (12–43) respectively (p< 0.001). The mean follow up time was 32.7 months and in that time there were no re-revisions for aseptic loosening. Histology demonstrated viable bone stock in the proximal femur where bone grafting had been impacted 2 years previously.

The OUH is a versatile hip prosthesis for use in revision hip arthroplasty and is especially well suited to proximal impaction bone grafting where it is possible to restore viable bone stock