Chiari medial displacement osteotomy.

The results of 36 Chiari medial displacement osteotomies of the pelvis were studied to determine the efficacy of the operation in the treatment of subluxated and/or painful dysplastic hips. Fifteen of 16 osteotomies performed for congenital hip dysplasia provided satisfactory coverage, pain relief, and increased function. The results were less consistent in patients with myelodysplasia, spasticity, and Perthes disease. The Chiari osteotomy is a technically exacting procedure capable of providing adequate femoral head coverage. This coverage facilitates pain relief and increased function. This procedure is most suited for those individuals with a painful hip subluxation in whom a concentric reduction is not possible.