Revision arthroplasty--femoral aspect: the concept to solve high grade defects.

Abstract

The concept of and the results with a long-stem revision prosthesis based on the universal hip system BiCONTACT experiences are presented. After removal of the loosened hip stem via a transfemoral approach, the defect zone is bridged by a long-stem prosthesis with distal interlocking for higher primary stability. After bone healing and reconstruction thanks to the fracture healing mechanism, the interlocking bolts are removed and the implant can be stabilized again in the proximal part of the femur. In this area, osseointegration is supported by the microporous coating Plasmapore. The first 109 procedures with 70% high-grade femoral defects where presented for an average of 5.25 (maximum 9.7) years. Harris score improved from 45 to 75 points and implant survival rate was 85.3%. Restoration and reorganization of the proximal bone stock could be observed clinically, radiologically, and histologically. Evaluation of re-revisions showed suboptimal surgical procedures, poor bone structure, too early removal of interlocking bolts, and undersized implants as reasons for failure using this technique. We conclude that biological revision with the long BiCONTACT stem with distal interlocking option is a concept to solve problems associated with high bone-loss situations.