Pneumatic broaching may prevent massive stem subsidence in femoral revision hip replacement

Abstract

Massive postoperative subsidence of the prosthesis is a major failure concern in revision hip replacement, as it can potentially provoke recurrent dislocation, secondary femoral fracture, and discrepancies in leg length. In this study, we aimed to evaluate whether the use of vibration-assisted broaching would offer the requisite control and reproducibility necessary to achieve axial stability for a tapered, rectangular revision stem in patients undergoing hip revision surgery. We evaluated the performance of the Zweymüller femoral revision stem implanted following pneumatic rasping in 61 patients (62 hips). There were 39 females and 22 males with a mean age of 72 years. Aseptic loosening was the indication for revision in most cases. According to the Paprosky classification, defects of the femur were grade 2 in 14 hips, grade 3 in 44 hips, and grade 4 in four hips. Ninety percent of the surgeries were first revisions. In the majority of procedures (58 procedures), we utilized anterolateral abductor splitting with the patient in the lateral position as our surgical approach. In six cases, we performed windowing of the femur diaphysis to facilitate cement removal. An extended trochanteric osteotomy was performed in two cases. In all cases, the femoral bed of the implant was modelled at the time of operation using progressively larger pneumatic broaches of 18-22 cm in length. The mean preoperative Postel Merle d'Aubigné (PMA) score was 9, which improved to 16.4 at the time of the last follow-up (mean: 4.8 years; range 3-7 years). No implant showed evidence of significant migration or loosening. During the operation, the specific use of the pneumatic hammer did not cause any complications. In conclusion, the use of the Zweymü ller femoral revision stem implanted following pneumatic rasping potentially minimizes complications and maximizes benefits. An extended follow-up is required to better understand the potential long-term benefits of this approach.