Unicompartmental knee replacement: a comparison of four techniques combining less invasive approach and navigation

We developed a nonimage-guided navigation system for unicompartmental knee replacement, suitable for both conventional and minimally invasive approaches. We performed a radiologic analysis of the accuracy of implantation with conventional nonnavigated instrumentation, conventional, open navigated instrumentation, minimally invasive navigated experimental instrumentation derived from conventional instruments, and minimally invasive navigation-dedicated instrumentation. Navigated technique allowed improving the accuracy of the radiologic implantation. Minimally invasive implantation was effective, but the accuracy may not reach that of the conventional navigated technique. Minimal invasive techniques have to be validated, because a loss of accuracy will negatively influence longterm outcomes.