Modified extended trochanteric osteotomy with preservation of posterior structures

The purpose of the study was to describe the technique and the clinical results of the modified extended trochanteric osteotomy (ETO) with a lateral approach to the hip. This osteotomy differs from those previously described, as it preserves the posterior part of the greater trochanter and its attached external rotators, the aim of this modification being to minimize the rate of hip dislocation. We reviewed the results of 105 extended sliding trochanteric osteotomies performed between January 2000 to January 2008. The indication for surgery was aseptic loosening in 83 cases, periprosthetic fractures in 10 cases, stem fracture in 5 cases, infection in 5 cases and instability in 2 cases. Minimum follow up was 20 months (mean, 65; range, 20-120 months). Mean length of the osteotomy was 17.6 cm (range, 9-30 cm). Mean Harris hip score improved from 39 points preoperatively to 73 at last follow up. Six stems (6%) needed revision for loosening. There was one case (1%) of osteotomy nonunion, and one case (1%) of greater trochanteric fragment nonunion and escape. Four patients (4%) dislocated postoperatively. In conclusion, our series of ETOs reveals a low dislocation rate achieved by preservation of the attachment of the external rotators and posterior capsule, and exhibits a union rate comparable to that of other series. We recommend the use of ETO in revision surgery of cemented stems and cementless well fixed distal ingrowth stems.