Repeatability of a Computer-Aided Optical Tracking System for Total Knee Replacement Surgery

The success of total knee replacement surgery depends critically on the restoration of limb alignment and on proper implant positioning [1]. Even with contemporary mechanical alignment instrumentation, errors in alignment correction and implant positioning do occur [2–5]. To improve upon the accuracy of conventional mechanical instrumentation, computer-aided navigation systems have been developed for total knee replacement surgery. Clinical studies have demonstrated that use of these systems for knee replacement surgery can lead to improved limb alignment and implant positioning [6–9]. While such systems have been shown to be clinically effective, their overall accuracy and repeatability in clinical use appears to be highly technique dependent [10]. The inherent repeatability (precision) of such systems has not been closely investigated.