Treatment of large femoral bone defects--15-year experiences with the cementless Bicontact revision stem with distal interlocking

Abstract

Aim: With the steady growth in the number of hip arthroplasty revision operations, the concept and long-term results of the Bicontact revision stem with distal interlocking for the treatment of extensive femoral bone defects were investigated in this prospective study.

Method: The first 156 stem revision operations performed between January 1992 and December 2002 were evaluated. The indication for operation was aseptic loosening in 133, stem fracture in 14, recurrent dislocation in 2 and reimplantation following Girdlestone removal of a septic prosthesis in 7. The cup component was revised at the same time in 74 cases.

Results: Higher-grade femoral bone defects were found intraoperatively in 66 %. The average age of the patients was 71.4 (34 - 88) years at operation and 76.9 (44 - 94) years at the last follow-up. The average period until follow-up, re-revision or loss to follow-up was 5.54 (0.1 - 14.9) years. The clinical and radiological follow-up rate (with reference to the total number of patients) was 35 % (55 von 156), and 51 % (55 of 107) with reference to patients still living. The median Harris Hip Score was 63.7 points. In the observation period, 12 stems were exchanged for a cemented standard stem, 5 stems were removed because of infection and 2 stems were revised because of periprosthetic fracture. The calculated survival rate for the stems after 14.9 years was 85.9 %.

Conclusion: The 15-year results confirm the biomechanical concept of the Bicontact revision stem with optional distal interlocking for the treatment of extensive bone defects in stem revision surgery.