Accuracy of Radiographic Assesment of acetabular component anteversion and inclination after tha in Comparision to CT based Measurement

Abstract

Introduction: Malposition of the acetabular component after total hip arthroplasty (THA) is related to dislocation of the prosthetic femoral head, increased polyethylene liner wear, and limited range of motion 1, 2, 3, 4, 5. The orientation of the acetabular component comprises inclination and anteversion. Although the inclination of the acetabular component can be easily measured on plain radiographs, calculation of the anteversion is difficult. There are several radiological methods for measuring the anteversion of the acetabular component after THA, and a single standardized method has not been established. Objectives To assess the accuracy of measurement of acetabular cup anteversion and inclination after THA using plain radiographs vs computed tomography-based measurements.To determine if plain radiograph is reliable method for determining acetabular cup anteversion and inclination. Methodology: The present descriptive observational study was carried out at Department of Orthopaedics, Sanjay Gandhi Institute of trauma and Orthopaedics, Bangalore during the period of November 2019 to October 2020 including 40 patients admitted for THA at Department of Orthopaedics, Sanjay Gandhi Institute of trauma and Orthopaedics, Bangalore with the objective to assess the accuracy of measurement of acetabular cup anteversion and inclination after THA using plain radiographs vs computed tomography based measurements and to determine if plain radiograph is reliable method for determining acetabular cup anteversion and inclination. Results: The angle of anteversion assessed on X ray and on CT, the difference was not statistically significant. It means though the anteversion angle on CT was slightly higher, but it was not significantly higher compared with X ray angle. (p>0.05). The angle of inclination assessed on X ray and on CT, the difference was not statistically significant. It means though the inclination angle on CT was slightly higher, but it was not significantly higher compared with X ray angle. (p>0.05).