Effectiveness of muscle transfers in myelomeningocele hips measured by radiographic indices.

Thirty-five hips with muscle weakness, in ambulatory myelomeningocele patients, received muscle transfer surgery. In each hip, procedures were done either to augment the abductor side of the joint (Sharrard transfer or external oblique transfer) or to weaken adduction (adductor release or adductor transfer) or both. In addition, femoral osteotomy was performed in some patients. Surgery was evaluated by reviewing preoperative and follow-up radiographs. If radiography demonstrated 5 degrees of improvement in the CE angle or the acetabular index, the hip was considered improved. Best results occurred when abductor and adductor procedures were combined, which resulted in radiographic improvement in eight of nine cases. When abductor and adductor procedures were not combined, only 6 of 26 hips were improved radiographically. These procedures may be indicated in the ambulatory myelomeningocele child with unilateral hip subluxation (CE angle approximately 0 degrees) but before complete dislocation has occurred. We support the trend away from major or frequent hip surgery in these patients. Our preferred procedure is to combine external oblique transfer with adductor transfer. All patients in this study continued to walk with a weak abductor gait following surgery.