Cementless modular total hip arthroplasty with subtrochanteric transverse shortening osteotomy for high hip dislocations

Abstract

Background Performing a total hip arthroplasty for a high hip dislocation is technically demanding and presents several challenges, with appropriate evaluation of the bone morphology of the hip and proper implant selection being critical for successful outcomes. Objective The purpose of our study was to evaluate the clinical and radiographic outcomes of cementless modular total hip arthroplasty for the treatment of high hip dislocations with sub-trochanteric transverse shortening osteotomy. Methods Sixty-eight hips with a high hip dislocation, were treated using a sub-trochanteric transverse shortening osteotomy and cementless modular total hip arthroplasty, retrospectively reviewed. Hip function was assessed using the Harris hip score, with hip abduction strength evaluated using the Trendelenburg test. Radiographic assessment included the measurement of leg length discrepancy, identification of implant loosening, localization of the hip center, and union at the osteotomy site. Results The mean follow-up period was 12.9 (range 5.2-16.8) years. The mean Harris hip score improved from a pre-operative score of 48.6 +/- 3.6 to 82.4 +/- 4.2 (p < 0.05). The hip was within the true acetabulum in all patients, postoperatively. Osteotomy union was achieved in 67 of the 68 hips (98.5%) in a mean latency of 12.5 +/- 0.6 weeks. The mean length of femoral shortening was 66.5 +/- 4.5 mm, with a mean pull-down length of the proximal part of 35.5 +/- 3.5 mm. Conclusion For the treatment of high hip dislocations with satisfactory clinical outcomes, the modular stem offers an adjustable anteversion angle to restore sufficient rotational stability and the transverse osteotomy provides sufficient compression pressure across the osteotomy site to facilitate union. Trial registration It was a retrospective study and approved by Istanbul Research and Training Hospital institutional Ethics Review Board (772-05/02/2016).