Digital protractor as an intraoperative guide to cup anteversion in total hip arthroplasty

Abstract

Abstract Introduction To explore if digital protractor could guide the anteversion of acetabular cup during primary THA and make it consistent with preoperative. Methods We retrospectively reviewed 172 cases of primary THA with direct anterior approach (DAA) over 2 years. The anteversion of acetabular cup were measured from computed tomography (CT) scan preoperative and de-identified plain radiographs postoperative by two blinded investigators who were not involved in the surgery. The effect of the digital protractor on the anteversion was determined using regression analysis. Results The mean anteversion for the THAs in digital protractor group was 15.5°and 21.4°in control group (P 25°. The correlation coefficient for the interobserver reliability of the measurement of the two investigators was 0.94. Conclusion The digital protractor is a practical tool in the DAA for THA to determine the anteversion of the acetabular prosthesis.

Keywords

• Digital protractor
• Anteversion
• Total hip arthroplasty
• Direct anterior approach