Caution required when using an intraoperative knee balancer in total knee arthroplasty.

Various knee balancers have been developed to assist surgeons in balancing the flexion and extension spaces during total knee arthroplasty. Devices typically are designed to measure the distance between spaces during total knee arthroplasty at a given force level. We analyzed the accuracy of one type of these devices. We found that the devices accurately measure distances, but are quite inaccurate at demonstrating reproducible forces.