Guided Growth of the Proximal Femur for Hip Displacement in Children With Cerebral Palsy

Background: Guided growth by 1 eccentric transphyseal screw has been used to correct lower limb deformities. Pilot animal studies showed encouraging results in producing varus deformity in the proximal femur. The purpose of this study was to report the preliminary results of guided growth surgery to treat spastic hip displacement. Methods: This case series study included consecutive patients who received soft-tissue release and guided growth at the proximal femur from January 2004 to May 2012 with minimal 2-year follow-up. Surgical indications were children with spastic cerebral palsy aged 4 to 10 years, a gross motor function classification system level IV or V, and hip displacement on 1 or both sides. Study outcomes were Reimer's migration percentage (MP) and the head-shaft angle (HSA). Results: Nine children with 13 spastic displaced hips received surgery at the age of 6.2 years and were followed up for a mean of 45.6 months. The mean MP improved significantly from 52.2% preoperatively to 45.8% at 3 months, 40.3% at 1 year, and 37.1% at 2 years after operation. HSA was unchanged in the first 3 months, and deceased from 173.3 to 166.4 degrees at 1 year (P<0.01) and to 162.7 degrees at 2 years postoperatively. The screw was usually backed out from the femoral epiphysis in the second postoperative year, and no radiologic bony bar or other surgical complications occurred. Conclusions: The immediate postoperative improvement of MP was the result of soft-tissue release. From postoperative 3 months to 2 years, the HSA was reduced by 10.6 degrees and the MP further improved by 8.7%. Less surgical dissection, faster recovery of motion, and less comorbidity than varus osteotomy make guided growth surgery a treatment option for coxa valga in spastic hip displacement in nonambulant cerebral palsy children.