Acetabular Dysplasia and Surgical Approaches Other Than Direct Anterior Increases Risk for Malpositioning of the Acetabular Component in Total Hip Arthroplasty

BackgroundPersistent acetabular dysplasia (AD) after periacetabular osteotomy has been hypothesized to increase the risk for malpositioning of the acetabular component. In this study, we investigate whether AD is an independent risk factor for cup malpositioning during primary total hip arthroplasty (THA).MethodsPatient demographics, surgical approach, presence of AD assessed using the lateral center-edge angle, and acetabular cup positioning determined using Martell Hip Analysis Suite were investigated in 836 primary THA patients enrolled in a prospective multicenter study.ResultsWe found that presence of AD, defined as the lateral center-edge angle of <25°, is an independent risk factor for malpositioning of the acetabular component during primary THA. Surgical approach other than direct anterior was also independently associated with malpositioned cups.ConclusionsSurgeons should therefore take special care during placement of the acetabular component in patients with AD.