Transpositional periacetabular osteotomy with allografting in patients with severe dysplasia: mid-term results.

Abstract

The purpose of this study was to analyse the extent of surgical correction and the early clinical results obtained using periacetabular osteotomy with allogenic bone grafting in patients with severe acetabular dysplasia. 44 hips in 38 patients were confirmed to have severe acetabular dysplasia and underwent this procedure. The mean follow-up period was 4.2 (range 1.5-8.2) years. Severe acetabular dysplasia was defined as a centre-edge angle less than 0°, an acetabular-head index less than 50% and an acetabular roof obliquity greater than 30°. Periacetabular osteotomy was performed with transpositional osteotomy of the acetabulum. The patients were divided into 2 groups according to the radiographic appearance: 34 hips in the early stage group and 10 hips in the advanced stage group. Postoperatively, the hips were radiographically assessed for dysplasia correction. The clinical results and hip function were measured using the Harris Hip Score. The average preoperative Harris Hip Score improved from 70 to 91 points at the latest follow-up. The average centre-edge angle, acetabular-head index and acetabular roof obliquity improved from -9° to 36°, 41% to 91% and 31° to 2°, respectively. Continuity of the Shenton line improved from 15 to 35 hips. No instances of nonunion or of transported segment collapse were encountered in this series; however, a grafted allogenic bone was absorbed in 1 case. The usage of allogenic bone grafting combined with periacetabular osteotomy is an effective technique for treating severe acetabular dysplasia. In this series, the early clinical and radiographic results were excellent.