Abstract

Lesions of the acetabular labrum have been suspected to be one factor responsible for failures of Chiari osteotomy. We undertook a prospective investigation to adress this question. Twenty-six adult patients (mean age 34.5 years) with 26 dysplastic hips were enrolled consecutively. All the hips studied showed arthritic changes. The labrum was inspected by arthroscopy during surgery (19 shelf acetabuloplasties and 7 Chiari procedures). All hips were followed for a minimum of 12 years (12-14 years). Sixteen dysplastic hips (62%) were found to have labrum tears. Computed tomography (CT)-arthrography findings were similar to arthroscopic observations in 13 hips. Coxomety results showed that the acetabular roof angle (HTE), cervico-diaphyseal angle (CDA) and lateralisation were higher in cases with acetabular labral tears. On the other hand, the ventral center-edge angle (VCEA) was lower in hips with labral tears. During the follow-up period, eight hips which had undergone a Chiari osteotomy were converted to total hip replacement. Adult dysplastic hips are at risk for presenting labral tears. Clinical signs appear to have limited diagnostic value. Coxa valga, a small lateral center edge angle and a high acetabular roof angle were found in this study to be associated with a higher incidence of labral tears. Contrary to previous data reported in retrospective studies, the results of the present prospective investigation suggest that labral tears do not compromise the outcome of acetabulum enlargement procedures.