Positioning of the acetabular component in cemented prostheses – radiographic calculation

Abstract

Objective to assess the reliability of the inclination angle and anteversion of acetabular cup component in patients with idiopatic osteoarthritis of the hip, aseptic necrosis and hip neck fracture using trigonometric formula and plain radiographs. Methods 66 patients underwent cemented total arthroplasty of 72 hips. The inclination of acetabular component was measured using plain radiograph. The acetabular component anteversion was measured using trigonometric formula. Results it was observed that, in the osteoarthritic hips, hip neck fracture and aseptic necrosis, the degree of agreement was highly significant (p < 0.0001), in the measurements of anteversion and inclination angles, among the three assessments, from intra as well as inter-observers. All the agreement pairs were of excellent degree (ICC > 0.80). Conclusion using plain radiographs and trigonometric formula, the method resulted to be highly accurate and reliable. Besides being easy to be calculated. No significant variation was found in the anteversion and inclination angles when compared with osteoarthritis of the hip, aseptic necrosis and hip neck fracture.