Chiari pelvic osteotomy in cerebral palsy.

Hip subluxation and dislocation in patients with cerebral palsy are challenging problems. The Chiari pelvic osteotomy has been commonly recommended as a technique for hip stabilization when acetabular dysplasia is present. We evaluated the results of Chiari osteotomy without concomitant femoral osteotomy in 24 hips in 23 patients with an average follow-up of > 7 years. Evaluation consisted of a pain and function questionnaire, chart review, physical examination, and review of serial radiographs. At final follow-up, 19 of 24 (79%) of the hips were painless, and 21 of 24 hips (88%) permitted unlimited sitting. Seven of 24 (29%) of hips, however, had a migration index of > or = 30%. Painful hips were associated with a greater migration index preoperatively, at 1 year postoperatively, and at final follow-up, and a greater height of the osteotomy above the edge of the acetabulum. Deterioration in the migration index (resubluxation) occurred largely in the first year postoperatively. Alternative acetabular procedures, simultaneous femoral osteotomies, or both may improve on these results. Long-term follow-up studies are necessary to compare the results of different treatments for spastic hip subluxation and dislocation to determine optimal treatment.