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

Abstract

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.

Figure 1.

A. Preoperative radiograph of a boy, aged 7.0 years and GMFCS level V, with severe subluxation of his right hip (MP 67%). B. 1 day after femoral osteotomy (varus, derotation and shortening), pelvic osteotomy, and bilateral soft tissue releases, showing good femoral head coverage bilaterally. The cortical bone segment removed from femur has been used as autograft in the open wedge of the pelvic osteotomy. C. 7.4 years postoperatively, at an age of 14.4 years, showing satisfactory femoral head coverage bilaterally, MP 19% (right hip) and 0% (left hip)

Figure 2.

A. Preoperative radiograph of a girl, aged 8.1 years and GMFCS level V, with severe subluxation of her left hip (MP 74%). B. 6 weeks after femoral and pelvic osteotomies of the left hip and bilateral soft tissue releases, showing good femoral head coverage. C. 2.9 years postoperatively (age 11.0 years), showing relapse of subluxation of her left hip (MP 51%).

Figure 3.

A. Preoperative radiograph of a girl, aged 5.7 years and GMFCS level V, with complete dislocation of her right hip (MP 100%) and subluxation of her left hip (MP 51%). B. 14 months after femoral and pelvic osteotomies of the right hip and bilateral soft tissue releases, showing slight subluxation of both hips (MP right hip 36% and left hip 37%). C. 7.3 years postoperatively (age 13.0 years), showing good position of right hip and deterioration of left hip (MP 64%).

Figure 4.

Kaplan–Meier survival plot (% survival with 95% confidence intervals) in all 39 hips, with time to failure (reoperation or MP ≥ 50%) as “survival”.