CT can enhance the measurement accuracy of radiographic anteversion of acetabular cup following total hip arthroplasty

Abstract

Background This study employed a novel method to measure radiographic anteversion (RA) of acetabular cups following total hip arthroplasty (THA) and validated its accuracy in comparison to traditional methods. The new method involves measuring anatomical anteversion (AA) using CT scans and radiographic inclination (RI) from anteroposterior (AP) radiographs, followed by calculating RA through a mathematical function. Methods The imaging data of 152 patients (192 hips) post-THA were retrospectively assessed twice for RA by two independent observers, utilizing Lewinnek’s method, Pradhan’s method, and the new method. Obtaining actual values ​​of RA from patient’s 3D imaging data. The intraobserver and interobserver reliability and accuracy of each method were subsequently compared. Results When compared to Lewinnek’s and Pradhan's method, the new method demonstrated superior intraobserver and interobserver reliability. Furthermore, the values obtained through the new method were closer to the actual values for acetabular RA. Conclusion Leveraging CT data, the new method introduced in this study enhances the accuracy of acetabular radiographic anteversion measurements.