A Simple Mathematical Standardized Measurement of Acetabulum Anteversion after Total Hip Arthroplasty

We invented a standardization method to measure the cup's anteversion after total hip arthroplasty without the influence of patient's position. We measured 68 radiographs of 10 patients after total hip replacement (THR) and calculated the error of each measurement, defined as the difference with the average of the same measuring method on the same patient. We also calculated the repeatability standard deviation (RSD) of each method according to the American Society for Testing and Materials, ASTM E691.