RESUMO
INTRODUCTION: Hip reconstruction is often necessary in children with cerebral palsy (CP) but is associated with high failure rates. Over-containment deeply seats the hip within the acetabulum at the time surgical reconstruction. The goal of this study is to evaluate the effect of over-containment on radiographic outcomes and failure rates in children with CP undergoing hip reconstruction. METHODS: This study is a retrospective chart review of children with CP that underwent hip reconstruction between 2010 and 2019 with at least 2 years of radiographic follow-up. Migration percentage (MP), acetabular index (AI), and neck shaft angle (NSA) were recorded preoperatively, postoperatively and throughout follow-up. Failures were defined as a MP at latest follow-up ≥30% or need for revision hip reconstruction. Hips were divided into groups based on postoperative MP-group 1 (over-containment group) had a MP≤0% and group 2 had an MP>0%. Radiographic parameters and failure rates were compared across Gross Motor Functional Classification Score (GMFCS) level, age at the time of surgery, and degree of preoperative subluxation. RESULTS: A cohort of 108 patients (197 hips) with an average age of 7.3±3.2 years met inclusion criteria with an average follow-up of 49.6 months (range: 24 to 118 mo). There were 147 hips in group 1 and 50 hips in group 2. At latest follow-up, group 1 demonstrated lower MP, AI, and NSA in comparison to group 2. The overall failure rate in our cohort was 8.1% (16 hips). Failure rates trended lowest in hips that were over-contained (6.1% v. 14.0%) although not statistically significant. Over-containment resulted in significantly lower failure rates in GMFCS IV/V hips, children under age 6 at the time of surgery and those with a higher degree of preoperative hip displacement (MP>50%). CONCLUSIONS: Over-containment at the time of hip reconstruction can positively affect radiographic outcomes and failure rates in children with CP. Over-containment should be considered in hips at high risk of failure, especially non ambulatory children with significant hip subluxation at an early age. LEVEL OF EVIDENCE: Level III-retrospective comparative study.
