Abduction Bracing Following Anterior Open Reduction for Developmental Dysplasia of the Hip Does Not Improve Residual Dysplasia or Reduce Secondary Surgery

Abstract

Background: Abduction bracing is commonly used following open reduction and spica casting of developmental dysplasia of the hip. However, there is little evidence to support or refute this practice that carries associated cost and burden for families. The purpose of this study was to determine the efficacy of abduction bracing after open reduction in improving the acetabular dysplasia and reducing the rate of secondary surgery for residual dysplasia. Methods: This is a retrospective study of patients treated with open reduction at a single tertiary referral center. Demographic data, severity of dislocation [International Hip Dysplasia Institute (IHDI) class], age at reduction, and casting duration were obtained. Patients were prescribed no bracing, part-time (≤18 h/d), or full-time (≥20 h/d) brace wear based on surgeon preference. Acetabular index (AI) measurements were obtained at cast removal and at 2- and 4-year follow-up. Results: A total of 146 hips underwent open reduction with 61% (89/146) of hips treated with abduction bracing. There was no difference between braced and nonbraced cohorts with regards to sex, age at time of reduction, dislocation severity, cast duration, immediate postcasting AI, or incidence of medial open reduction. There was no difference in hips treated with or without brace following open reduction with regards to AI at 2 years postreduction (31.8±6.7 vs. 30.4±6.1 degrees, P=0.27) or at 4 years postreduction (24.9±6.5 vs. 24.7±6.5 degrees, P=0.97). However, further analysis showed lower mean AI at 2-year follow-up for braced versus nonbraced patients following medial open reduction (30.0±5.7 vs. 34.5±7.0 degrees, P=0.02). This difference was no longer present at 4-year follow-up (26.6±6.8 vs. 24.2±6.6 degrees, P=0.44). However, 4/19 (21%) nonbraced hips underwent secondary surgery for residual dysplasia and were consequently excluded from the AI measurement at 4 years postreduction (compared with 4/39 [10%] braced hips within the same time period). There was no difference in the rate of secondary surgery between braced and nonbraced hips (30% vs. 33%, respectively, P=0.70). Multivariate analysis demonstrated that neither IHDI classification, bracing, nor age at reduction predicted residual dysplasia. Conclusions: Abduction bracing following anterior open reduction for developmental dysplasia of the hip is not associated with decreased residual dysplasia at 2/4 years postreduction or with decreased secondary surgery. These results suggest that abduction bracing following anterior open reduction may not provide clinical benefit. However, abduction bracing may be beneficial following medial open reduction. A prospective study is necessary to provide more definitive recommendations. Level of Evidence: Level III—therapeutic study.