Proximal Femoral Screw Hemiepiphysiodesis in Children With Cerebral Palsy Improves the Radiographic Measures of Hip Subluxation

Abstract

Background: Proximal femoral screw hemiepiphysiodesis (PFSH) is a promising technique for treatment of hip subluxation in children with cerebral palsy (CP). The aim of this study is to report radiographic outcomes of PFSH and to evaluate its role in changing the natural history of hip displacement in children with CP.

Methods: This is a single center retrospective chart review of children with CP that underwent PFSH with at least 2 years of radiographic follow-up. Demographic information, surgical details, complications, additional surgical procedures, and need for screw exchange were recorded. Radiographs were assessed for migration percentage (MP), neck shaft angle (NSA), head shaft angle (HSA), and articular trochanter distance preoperatively as well as at 6 months, 1 year, 2 year, and latest follow-up postoperatively. Hips were divided into group 1 (no previous hip surgery) and group 2 (PFSH performed after hip reconstruction). Hips with 2 years of preoperative radiographic data were included in the natural history cohort.

Results: Twenty-three patients (44 hips) met inclusion criteria with an average age of 7.3±1.7 years and a mean follow-up of 33.5 months. Group 1 and group 2 had 32 and 12 hips, respectively. Group 1 had significant improvement in all parameters (ΔMP=5%, ΔNSA=13 degrees, ΔHSA=15 degrees) group 2 showed improvements in NSA and HSA (ΔNSA=4 degrees ΔHSA=8 degrees) with only HSA reaching significance and MP remaining unchanged. All radiographic measurements worsened in the 2 years before surgery (N=25, natural history group) and improved after PFSH. Screw exchange occurred in 12 hips (27.2%) at an average of 33 months (range 27 to 42 mo) with 2 hips also undergoing pelvic osteotomy at that time. Three hips had a MP >50% at follow-up with 2 hips in group 1 undergoing hip reconstruction. No complications were noted.

Conclusion: PFSH effectively alters proximal femoral growth and can improve hip subluxation in children with CP. Screws often need to be exchanged and hips should be carefully monitored.

Level of evidence: Level III-retrospective comparative study.