Femoral and pelvic osteotomies for severe hip displacement in nonambulatory children with cerebral palsy: a prospective population-based study of 31 patients with 7 years’ follow-up

Background and purpose — There is no consensus regarding the optimal treatment of hip displacement in children with cerebral palsy (CP). This prospective study assessed the outcome of femoral and pelvic osteotomies for severe hip displacement in nonambulatory children and analyzed prognostic factors for outcome. Patients and methods — 31 nonambulatory children (20 boys), recruited from a population-based screening program, consecutively underwent unilateral (23) or bilateral (8) osteotomies and bilateral soft-tissue releases at a mean age of 6.1 years (2.2–9.9). The procedures were femoral varus osteotomy alone (20 hips) and combined Dega-type pelvic osteotomy and femoral osteotomy (19 hips). Final outcome was termed good if the patient had not undergone further bony surgery and migration percentage (MP) was < 50%. The mean follow-up time was 7.1 years (3.8–11). Results — The mean preoperative MP was 69% (36–100). The outcome was good in 22 patients (29 hips) and poor in 9 patients (10 hips). Mean time to failure was 3.6 years (1.0–6.0). GMFCS level V and high MP 1-year postoperatively were statistically significant risk factors for poor final outcome. There was a higher rate of good outcome after combined osteotomies compared with isolated femoral osteotomy, but the difference was not statistically significant (p = 0.2). Interpretation — Better primary correction was obtained after combined femoral and pelvic osteotomies than after isolated femoral osteotomy, indicating that combined osteotomies are the preferred method in hips with the most severe degrees of displacement. Prophylactic femoral osteotomy of the contralateral non-subluxated hip is hardly indicated.