Changes in acetabular component alignment due to screw fixation in patients with hip dysplasia

Introduction:Adequate initial stability of the acetabular cup is essential for total hip arthroplasty (THA). However, changes in the alignment of the acetabular component caused by screw fixation are concerning in patients with inadequate bone stock. This study aimed to investigate the effects of screw fixation on the alignment of the acetabular component in THA patients with hip dysplasia.Methods:We retrospectively examined 256 hips (range 28–87 years) that underwent THA using a navigation system. Patients were divided into 2 groups based on the presence or absence of changes in the alignment of the intraoperative acetabular cup, and univariate and multivariate analyses were performed to identify factors that were predictive of changes in acetabular component alignment after screw fixation in 2 dimensions: inclination and anteversion.Results:Screw fixation led to a mean change in inclination of 1.6° (range 0–10°) and a mean change in anteversion of 1.4° (range 0–14°). The Crowe classification, the presen...