Effect of pelvic osteotomy in the skeletally immature on acetabular coverage

Although pelvic osteotomy in children has been effective in re-establishing containment of the hip joint, its impact on hip joint development with respect to acetabular coverage is ill defined.

The purpose of this study is to determine the prevalence of acetabular overcoverage in patients who had pelvic osteotomy during childhood and its impact on patient function.

Between 1980 and 2008, all patients who had a pelvic osteotomy done at our institution for non-neuropathic hip dysplasia (DDH) or secondary to Legg-Calvé-Perthes disease (LCP) prior to skeletal maturity were reviewed. A clinical assessment and the WOMAC, UCLA Activity Score, Marx activity score, and SF-36 quality-of-life questionnaires were completed. A standardized AP pelvic X-ray was performed to determine the acetabular coverage, signs of retroversion, and degenerative changes.

Twenty-eight patients (32 hips) were identified, of which 14 (9 DDH, 5 LCP) agreed to participate. Impingement sign was positive in eight patients (six DDH, two LCP). Crossover and ischial spine signs were each present in ten hips. Tonnis grades were: 0 in 1 hip, 1 in 10 hips, 2 in 2 hips, and 3 in 1 hip. The mean Tonnis angle was 11.6 ± 8.6°. The mean CE angle was 24.0 ± 15.9° with six hips having a CE angle <20° and one hip with a CE angle >40°. There was no correlation between crossover sign or ischial sign and Tonnis grade (p = 0.739), hip pain (p = 0.520), or impingement sign (p = 1.00).

Acetabular overcoverage is common in patients who underwent pelvic osteotomy during childhood. No correlation was identified between retroversion and hip pain in our patient cohort.