Less invasive innominate osteotomy

In 1961, Salter described the innominate osteotomy for the treatment of dysplastic acetabulum in children presenting late with developmental dysplasia of the hip. He recommended the Gigli saw as the safest instrument for the osteotomy cut and his postoperative immobilization was with a hip spica cast. These have been the standard practice. However, an extensive exposure is required to facilitate passage of the Gigli saw under the sciatic notch while the application of a hip spica can be difficult and prolongs anaesthetic time. We describe a less invasive technique using an oscillating saw for the osteotomy cut. This allows for minimal exposure hence short operation time and quick recovery. We use an abduction brace for our postoperative immobilization thereby significantly reducing anaesthetic time. Fifty innominate osteotomies performed in 49 patients using this technique were reviewed retrospectively. There were 46 female and three male patients. The senior author performed all surgeries. The average age at surgery was 24 months (18-54) and the mean follow-up period was 25 months (12-60). The mean preoperative acetabular index was 35.1 degrees , whereas the acetabular index at final follow-up was 14.9 degrees (P<0.0001). Average duration of surgery was 25 min with minimal blood loss (less than 50 ml). All went home by the second postoperative day. There was no intraoperative complication. Two patients had minor superficial wound infections that resolved uneventfully. There was no loss of correction. We suggest that the oscillating saw is a safe instrument for performing an innominate osteotomy, it allows for less invasive surgery hence less morbidity and quicker recovery without compromising the surgical outcome. The abduction brace can be used for immobilization after innominate osteotomy without loss of correction.