Computer assisted navigation in total knee arthroplasty: comparison with conventional methods.

The success of knee arthroplasty is dependent on many factors. Postoperative extremity and component alignment are important determinants of outcome and longevity. Malalignment (>3 degrees ) results in higher failure rates. Computer-assisted navigation devices were developed to improve implant positioning. This study evaluated the early outcomes of a high-volume fellowship-trained surgeon relative to component positioning and limb alignment using an image-free navigation system. The navigation group consisted of 116 consecutive patients, and the conventional group consisted of 51 consecutive patients. The postoperative mechanical axis was within 3 degrees of neutral mechanical alignment in 95% of the navigation cases vs 84% of the conventional cases (P < .02). The range of the alignment and component position measurements narrowed, and the undesired outliers decreased. Accuracy was improved with navigation. Navigation was a viable device to improve the outcome of total knee arthroplasty relative to limb and component alignment.