Long-term effects of intertrochanteric varus-derotation osteotomy on femur and acetabulum in spastic cerebral palsy: an 11- to 18-year follow-up study.

An intertrochanteric femoral osteotomy is carried out to correct intoeing gait and to improve hip centration in patients with spastic cerebral palsy. The long-term effect of such osteotomies on the neck-shaft angle (NSA) and anteversion angle (ATA), as well as on hip-joint centration, was evaluated in 63 hips of 45 patients with observation times of 11-18 years (mean, 15.4). The postoperative loss of correction of the NSA and ATA was the more pronounced the younger the patients were at the time of intervention. This was particularly true when the hip joint was subluxated or dislocated and when the operation was done before the age of 4 years. Patients of this age group lost 96% of the correction of the NSA and 42% of the ATA. Hip centration always improved, but corrective femoral osteotomy alone did not result in a sufficient coverage in cases of subluxation and dislocation in the short and long term.