This retrospective cohort study asked whether any radiographic measure — fracture characteristics or hip dysplasia markers — can independently predict hip instability after posterior acetabular wall fractures involving ≤50% of the wall. 68 patients underwent EUA, and multivariate logistic regression was used to test 10 variables. The answer: none qualified as independent predictors.
The standard workflow for posterior wall acetabular fractures ≤50% has always included EUA, but there has been persistent hope that a reliable radiographic predictor could spare some patients the OR trip. Firoozabadi et al. (2015) raised optimism by reporting the superior fracture exit point as a useful marker.
This study systematically tested that claim and expanded the search to include DDH markers. When multiple variables were analyzed together, none held up as independent predictors. The univariate signals from the posterior wall sign, ischial spine sign, and exit point proximity were real but not independently actionable.
The clinical take: when you have a posterior wall fracture ≤50% on CT, no combination of plain film findings or fracture geometry reliably clears or condemns the hip. Take the patient to the OR for EUA with dynamic stress views before committing to nonoperative management.
The posterior wall sign and ischial spine sign remain useful diagnostic markers for DDH, but do not use their presence or absence to predict fracture instability in isolation.
This retrospective cohort study asked whether any radiographic measure — fracture characteristics or hip dysplasia markers — can independently predict hip instability after posterior acetabular wall fractures involving ≤50% of the wall. 68 patients underwent EUA, and multivariate logistic regression was used to test 10 variables. The answer: none qualified as independent predictors.
The standard workflow for posterior wall acetabular fractures ≤50% has always included EUA, but there has been persistent hope that a reliable radiographic predictor could spare some patients the OR trip. Firoozabadi et al. (2015) raised optimism by reporting the superior fracture exit point as a useful marker.
This study systematically tested that claim and expanded the search to include DDH markers. When multiple variables were analyzed together, none held up as independent predictors. The univariate signals from the posterior wall sign, ischial spine sign, and exit point proximity were real but not independently actionable.
The clinical take: when you have a posterior wall fracture ≤50% on CT, no combination of plain film findings or fracture geometry reliably clears or condemns the hip. Take the patient to the OR for EUA with dynamic stress views before committing to nonoperative management.
The posterior wall sign and ischial spine sign remain useful diagnostic markers for DDH, but do not use their presence or absence to predict fracture instability in isolation.