An incomplete periacetabular osteotomy for treatment of neuromuscular hip dysplasia.

Standard innominate osteotomies that are recommended for treatment of the typical form of developmental dysplasia of the hip are not recommended for dysplasia associated with neuromuscular disorders. A periacetabular osteotomy that permitted accurate correction of the posterolateral acetabular deficiency was done on 40 patients (50 hips). The purpose of this study was to present the surgical technique, to evaluate whether it can improve acetablular dysplasia, and to provide stable hips. The patients had a mean age of 9.5 years at the time of surgery. The medial cortex of the ilium was left intact, whereas the supraacetabular and retroacetabular cancellous bone, and posterolateral cortical bone were cut. The posterior cut extended down to the triradiate cartilage, or through its former site, respectively. Forty-one hips were evaluated at a mean followup of 5.3 years (range, 2-11.7 years) after surgery. The mean acetabular index improved from 32 degrees preoperatively to 12 degrees at followup. The mean migration percentage improved from 77% to 13%. A redislocation or unstable hip occurred in two patients. According to caregivers, surgery improved personal care, positioning, and comfort. This osteotomy decreases the radius of the elongated acetabulum, provides coverage by articular cartilage particularly at the posterolateral aspect of the acetabulum, and preserves the entire medial wall of the ilium.