Differences in measurement of lower limb alignment among different registration methods of navigation and radiographs in TKA using the OrthoPilot system.

The purposes of this study were (1) to compare lower limb alignment measurements between radiographs and computer-assisted surgery and (2) to evaluate the discrepancy in lower limb alignment between computer-assisted surgery with a high tibial osteotomy protocol and computer-assisted surgery with a total knee arthroplasty (TKA) protocol in the same knee. Seventy-one TKAs were performed on patients with primary osteoarthritis using computer-assisted surgery. Preoperative lower limb alignment was measured using the mechanical axis during bipedal, weight-bearing, whole-leg anteroposterior radiography (measure 1).