Implication of acetabular width on the anteroposterior pelvic radiograph of patients with developmental dysplasia of the hip.

Radiographic parameters that can help acetabular reconstruction during total hip arthroplasty (THA) for patients with developmental dysplasia of the hip (DDH) are few. The radiographs of 138 dysplastic hips that had undergone cementless THA were evaluated regarding the acetabular width above the acetabular component and the coverage of the component by native bone. The acetabular reconstruction process was simulated using 3D models from CT data, and the acetabular component coverage was calculated in 3D space based on the measurement and algorithm we proposed. Significant positive correlation between the acetabular width and the acetabular component coverage was found. Our study introduced a useful parameter, which can mark the superior reference position of the acetabular component for acetabular reconstruction in DDH patients.