Deciding whether to treat isolated mild dysplasia in infantile DDH: Identifying factors in decision making

Abstract

Purpose: There is significant variability in brace treatment indications for infantile acetabular dysplasia in the absence of hip dislocation or subluxation. This study’s purpose was to evaluate characteristics of treated and untreated patients in our practice.
Methods:  A retrospective chart review was performed of patients aged 0-12 months who were referred to orthopedics with concern for DDH. Demographic and clinical information, as well as provider and radiographic information were recorded for analysis. Five surgeons were independently asked to review de-identified radiographs and note which subjects warranted treatment. A consensus diagnosis of “dysplasia”, “no dysplasia”, or a lack of consensus were considered as independent variables. Univariate and Classification and Regression Tree (CART) analysis was performed to determine predictors of treatment.
Results:  Mean acetabular inclination (30.6º vs. 28.2º; p=0.006) and the incidence of abnormal abduction (p=0.002) were higher for the group that was treated for dysplasia. CART analysis showed that patients with a consensus diagnosis of radiographic dysplasia were more likely to receive treatment than those without consensus, or a consensus of no dysplasia (p<0.001). If consensus was not reached, then abnormal abduction on exam was the next strongest predictor of treatment (p<0.001). Radiographic impression, which was the primary determinant of treatment, exhibited only fair intrarater and interrater reliability.
Conclusions:  We studied factors that led to the diagnosis and treatment of DDH in an infant population. We observed that radiographic impression and abnormal abduction on exam were the only reliable factors predictive of treatment among our practice.