Z-plasty for severe gluteal muscle contracture in children

Abstract

Purpose. To review the records of 363 patients with severe gluteal muscle contracture to determine its mechanism, underlying pathology, and treatment outcome. Methods. Records of 136 males and 227 females aged 5 to 18 (mean, 12.2) years who underwent Z-plasty for bilateral (n=347) or unilateral (n=16) severe gluteal muscle contracture were reviewed. Severe gluteal muscle contracture was classified as typical (n=52) or special (n=311). The typical type is associated with symptoms of positive out-toe gait, Ober sign, backextending test, cross-leg test, squatting with knee side-by-side test, and hip dysfunction. It is further subdivided into mild (n=0), moderate (n=40), or severe (n=12). The special type is associated with additional symptoms of pelvic tilt and leg length discrepancy (<2 cm in 181 hips, 2–4 cm in 82 hips, and >4 cm in 48 hips). 311 hips had pelvic tilt and 47 hips had lumbar compensatory scoliosis. Treatment outcome was assessed at 6 months. Hip functional score was assessed at the final follow-up. Results. The mean hospitalisation period was 11 days. After a mean follow-up of 1.5 years, the mean hip functional score improved from 8.03 to 11.69; improvement was higher in children (age 5–13 years) than in adolescents (age 14–18 years) [3.7 vs. 2.9, p<0.001]. At 6 months, outcome was excellent in 280 hips, good in 80, fair in 3 hips, and poor in 0. The 3 hips with fair outcome had persistent slight pelvic tilt and swaying gait. Two of them had preoperative leg length discrepancy >4 cm, and intra-operatively the contracture band severely affected the joint capsule. The third patient did not comply with postoperative exercises. Conclusion. Surgical treatment for severe gluteal muscle contracture achieved good outcome.