Treatment of internal rotation gait due to gluteus medius and minimus overactivity in cerebral palsy: anatomical rationale of a new surgical procedure and preliminary results in twelve hips.

Spastic overactivity of the anterior fibers of the gluteus medius and minimus can result in an internal rotation gait associated with excessive hip and pelvic rotation. The currently advocated operation for this problem can result in weakness of hip abduction. The anatomical features of the gluteal muscles suggest that this gait abnormality can be corrected by selectively reducing the internal rotator function of the anterior fibers of the glutei without disturbing the abductor fibers. Such an operative procedure was devised and performed on 12 hips. The gait improved in all hips without any demonstrable weakness of the hip abductor power.