Evaluation of Component Positioning in Primary Total Hip Arthroplasty Using an Imageless Navigation Device Compared With Traditional Methods

Acetabular orientation affects the success of total hip arthroplasty. Computer-assisted navigation systems may reduce positional errors. Total hip arthroplasty results were analyzed using an imageless navigation system. We hypothesized that reliability and accuracy would improve. One hundred forty-nine total hip arthroplasties were performed using minimally invasive surgical techniques in 3 cohorts: manual (n = 53), initial navigation cases (n = 49), navigation second series (n = 47). Manual patients' cup orientation variation from desired range was −19° to +18° anteversion (SD, 9.1°), −11° to +25° abduction (SD, 6.7°). Navigation variation from desired was −18° to +15° (SD, 7.3°) in group 1 and −15° to +9° (SD, 5.9°) in group 2 in anteversion and −15° to +13° (SD, 6.1°) in group 1 and −15° to +11° (SD, 4.7°) in group 2 in abduction. Results were statistically significant. There were significant differences for operating room time and estimated blood loss, but not incision size or body mass index. Navigation provided controlled, reproducible acetabular alignment; but a learning curve existed in terms of accuracy, estimated blood loss, and operating room time.