LAUSR

Despite its success, total hip arthroplasty (THA) remains associated with potentially significant complications associated with component malposition. Preoperative planning can mitigate some of these potential concerns; however, the accurate intraoperative delivery of preoperative targets can be challenging. Computer-assisted navigation may assist with intraoperative target delivery, although the integration of these two technologies is relatively uncommon. We retrospectively reviewed cases of THA planned with a computed tomography-based preoperative planning software and performed with the use of an imageless, computer-assisted navigation system. Postoperative acetabular component orientation from radiographs was compared with preoperative targets and intraoperative navigation measurements. A total of 76 patients were included in the analysis. The mean anteversion target (20.0°±3.1°) did not differ significantly from the mean intraoperative navigation measurement (20.5°±3.3°; P=.30; mean difference, 2.2°±2.3°). The mean radiographic measurement (26.6°±6.5°) differed from the target by a mean of 7.5°±6.1° (P<.001). The mean inclination target (38.4°±1.9°) did not differ significantly from the mean intra-operative measurement (38.0°±1.5°; P=.20; mean difference, 1.3°±1.7°) but differed from the radiographic measurement by a mean of 5.2°±4.2° (41.8°±5.6°; P<.001). No adverse events were reported in the 90-day period following the index procedure. Our study demonstrated that an imageless navigation system can accurately deliver computed tomography-derived preoperative targets for acetabular component orientation. Differences noted on radiographs may be due to the difference in patient positioning for the postoperative imaging (standing) as compared with preoperative imaging or surgery itself (supine). [Orthopedics. 202x;4x(x):xx-xx.].