Exact determinants of hip instability have not been established for fractures of the posterior wall of the acetabulum involving ≤50% of the wall. Therefore, examination of the hip under anesthesia (EUA) is routinely performed. Recently, the superior exit point of the fracture has been reported to be an important identifiable risk factor. Pre-existing adult hip dysplasia (developmental dysplasia of the hip [DDH]) is thought to have a similar role. The purpose of this study was to determine if any known radiographic measurements and signs associated with DDH, or any fracture characteristics, are independent risk factors for hip instability after fracture of the posterior wall of the acetabulum.
Consistent with previous studies, univariate analyses identified certain radiographic findings as significant risk factors for hip instability in the setting of a fracture of the posterior wall of the acetabulum. However, subsequent multivariate logistic regression modeling showed that no studied variable was an independent risk factor. Our results indicate that important factors leading to hip instability are yet to be identified or the contributions of the measured variables are relatively small. Therefore, EUA should remain the main clinical determinant of hip stability status.
Level of evidence: Prognostic Level IV. Copyright remains with the authors and publisher.
Exact determinants of hip instability have not been established for fractures of the posterior wall of the acetabulum involving ≤50% of the wall. Therefore, examination of the hip under anesthesia (EUA) is routinely performed. Recently, the superior exit point of the fracture has been reported to be an important identifiable risk factor. Pre-existing adult hip dysplasia (developmental dysplasia of the hip [DDH]) is thought to have a similar role. The purpose of this study was to determine if any known radiographic measurements and signs associated with DDH, or any fracture characteristics, are independent risk factors for hip instability after fracture of the posterior wall of the acetabulum.
Consistent with previous studies, univariate analyses identified certain radiographic findings as significant risk factors for hip instability in the setting of a fracture of the posterior wall of the acetabulum. However, subsequent multivariate logistic regression modeling showed that no studied variable was an independent risk factor. Our results indicate that important factors leading to hip instability are yet to be identified or the contributions of the measured variables are relatively small. Therefore, EUA should remain the main clinical determinant of hip stability status.
Level of evidence: Prognostic Level IV. Copyright remains with the authors and publisher.