[Total knee arthroplasty with the use of patient specific instruments. The VISIONAIRE system].

BACKGROUND: Accurate component positioning and correct post-operative whole-leg alignment are crucial for ensuring the optimal long-term performance of a knee replacement. Patient-specific instrumentation (PSI) was introduced in an attempt to reduce outliers in the positioning of components and in the alignment of the leg axis in comparison with conventional techniques. METHODS AND
RESULTS: A review of our own investigations and studies by other groups, it has been shown that PSI could reduce the amount of outliers in the positioning of tibial and femoral components and in whole-leg alignment. In this way, PSI differs from other procedures for improving component placement, such as navigation, for which no advantage could be demonstrated, especially with regard to rotation in comparison with conventional techniques. In this publication we focus on the VISIONAIRE PSI system (Smith&Nephew). In addition, the efficiency aspects of PSI are discussed, which differ from the conventional method because of the use of disposable instruments.