Despite advances in surgical techniques and instrumentation, current intra-operative estimations of acetabular version in total hip arthroplasty are of limited accuracy. In the present study, two experienced orthopedic surgeons compared intra-operatively measured (using portable imaging) anteversions and vertical inclinations of acetabular components with those measured using standardized radiographs post-operatively in 40 patients. Of the all vertical inclinations measured from intra-operative radiographs, 72.5% (n=29) were within +/-2 degrees , and 97.5% (n=39) were within +/-5 degrees of those determined using post-operative radiographs, and for anteversion, 52.5% (n=21) were within +/-2 degrees , and 97.5% (n=39) were within +/-5 degrees . Post-operative radiographs demonstrated that 90.0% (n=36) of vertical inclinations and anteversions were within the adequate zone. Obviously, our method has its limitations, but the authors conclude that the method described in this article better allows surgeons to verify acetabular version intra-operatively. In particular, the described method is suitable in cases with a deformed acetabular anatomy and difficult revision surgery.
Keywords: Acetabular Cup; Anteversion; Arthroplasty, Replacement, Hip; Vertical Inclination.