Usefulness of Preoperative Planning for Total Hip Arthroplasty Using a 3-Dimensional Template

Abstract

Plain X-ray images and 2-dimensional templates have previously been used for preoperative planning of total hip arthroplasty (THA). Recently, planning using CT images and 3-dimensional templates, aiming at higher accuracy, has occasionally been reported. The objective of this study was to investigate the usefulness of 3-dimensional templates for preoperative THA planning. Fifteen hips in 15 patients who underwent initial THA between April and September 2012 were investigated. The implant size determined by both 2- and 3-dimensional preoperative planning was compared with the size of the implant actually used in surgery, and the concordance rate was investigated. The concordance rate was analyzed statistically using the chi-squared test. The rate of complete concordance afforded by 2-dimensional preoperative planning (2D) cups was 40% (6 of 15 patients), whereas that for 3-dimensional preoperative planning (3D) cups was 67% (10/15). The rates of complete concordance for 2D and 3D stems were 27% (4/15) and 40% (6/15), respectively. The concordance rates for 2D cups and stems tended to be higher, but were not significantly different from those of 2D cups and stems. When cases one -size larger or smaller were included in the concordance rate, the rates for cups and stems were 93% (14/15) for both 2D and 3D. No significant difference was noted in the size concordance rate between 2D and 3D templates for preoperative THA planning. However, preoperative 3D planning has several advantageous features, and we intend to continue our investigation.