Revision of failed open reduction of congenital dislocation of the hip.

We report a review of 33 hips (32 patients) which had required repeat open reduction for congenital dislocation of the hip. They were followed up for a mean of 76 months (36 to 132). Factors predisposing to failure of the initial open reduction were simultaneous femoral or pelvic osteotomy, inadequate inferior capsular release, and inadequate capsulorrhaphy. Avascular necrosis had developed in more than half the hips, usually before the final open reduction. At review, 11 of the hips (one-third) were in Severin grade 3 or worse; five had significant symptoms and only ten were asymptomatic and radiographically normal. Once redisplacement has occurred after primary open reduction, attempts to reduce the head by closed means or by pelvic or femoral osteotomy are usually unsuccessful and a further open reduction is necessary.