RESUMEN
PURPOSE: Periprosthetic fractures in cases without prior loosening of the stem can be treated with open reduction and internal fixation, but cases with preexisting loosening and/or bone defects present specific challenges to the surgeon. The keys to the success of intramedullary stabilization of femoral fractures--reconstruction of length, axis and rotation rather than meticulous reduction of the fragments and minimal impact on fragment vascularization by the surgical approach--can be transferred to the treatment of periprosthetic fractures. METHOD: The Bicontact revision stem can be regarded as a combination of an interlocking nail in its distal part and a proximally coated femoral stem in its proximal part. The transfemoral approach respects the vascularization of the bone, although it is not minimally invasive. Forty-one patients with a mean age of 72.3 years and a periprosthetic fracture were included in this study. According to the Vancouver classification there were 2 type A fractures of the trochanteric region, 14 were B1, 8 were B2 with prior loosening, 13 were B3 with significant bone loss, and 2 fractures were distal to the tip of the prosthesis (type C). RESULTS: In all patients, intramedullary stabilization with a Bicontact revision stem was performed. All but three fractures healed (pathologic fracture with multiple myeloma in one case, impaired bone healing in two cases). In 7 patients, further procedures had to be undertaken (new periprosthetic fracture in 2, loosening and revision with a standard prosthesis in 2, revision with a long stem prosthesis together with bone grafting in 3 cases). At follow-up, after a mean of 4.3 years, all patients were able to walk, and the mean Harris Hip Score was 71.1 points. CONCLUSION: In conclusion, combined application of the principles of intramedullary nailing and of uncemented total hip replacement by use of the distally interlocked Bicontact revision stem enables successful treatment of periprosthetic femoral fractures.