Long-term outcome after open reduction through an anteromedial approach for congenital dislocation of the hip

Abstract

We reviewed the long-term outcome of open reduction of ninety-three congenitally dislocated hips (in seventy-six children) through an anteromedial approach. The average age of the patients was fourteen months (range, two to fifty months) at the time of the reduction and eleven years (range, four to twenty-three years) at the time of the most recent follow-up evaluation. At the most recent follow-up evaluation, sixty-six hips (71 per cent) had an excellent or good result, twenty-four (26 per cent) had a fair result, and three (3 per cent) had a poor result, according to the Severin classification system. An inverted neolimbus at the time of the operation and postoperative growth disturbance of the femoral head were associated with a poor roentgenographic result. According to the classification of Bucholz and Ogden, twenty-two hips (24 per cent) had type-II avascular necrosis, thirteen hips (14 per cent) had type-III, three (3 per cent) had type-IV, two (2 per cent) had non-classifiable lesions, and fifty-three (57 per cent) did not have avascular necrosis. A high hip dislocation and an operation after the age of twenty-four months were associated with a higher rate of growth disturbances of the femoral head. With the numbers available for study, we did not find any association between short-term preoperative traction, ligation of the medial circumflex vessel, or the type of neolimbus and the prevalence of growth disturbances. Two hips redislocated postoperatively, and seven had transient stiffness. We consider the anteromedial approach to be useful in the management of patients with congenital dislocation of the hip who are twenty-four months old or less. The advantages of this approach include direct access to the obstacles to reduction, avoidance of damage of the iliac apophysis and the abductor muscles, minimum blood loss, the need for only a single operative session for treatment of both hips, and a cosmetically acceptable scar. The prevalence of type-II growth disturbances of the femoral head was higher than had been expected, emphasizing the need for additional investigation.