Gluteus maximus contracture.

Abduction contracture of the hip (frog-leg deformity) is caused by contracture of the gluteus maximus muscle. A simple operation consisting of complete detachment of involved fibrous portions of the gluteus maximus from the greater trochanter to the ischial tuberosity is sufficient to release the contracture and enable the patient to squat without abducting the hips. Possible sciatic nerve injury is avoided by a periosteal elevator inserted between the muscle and the greater trochanter before division of the muscle. All patients showed marked improvement, and complications were virtually nonexistent. The etiology is probably associated with injections, but keloidal collagen disease may be important. A small incision is desirable because skin keloid formation invariably occurred in 200 cases followed for one to eight years.