Assessment of joint laxity following total knee arthroplasty: A comparison of tensioner device, navigation, and robot evaluation.

Abstract

Appropriate soft-tissue balance is essential for total knee arthroplasty (TKA). Widely used techniques to evaluate soft-tissue balance are measuring the joint gap using tensioner devices, the robot and the navigation. We compared soft-tissue balance evaluated using tensioner, navigation, and robot tools. 81 patients who underwent bi-cruciate stabilized (BCS) TKA were included. 41 patients were performed using the navigation (Group N) and 40 patients were performed using the robot (Group R). After the final implantation, the joint laxities were measured using tensioner device (JLT) and navigation (JLN) in group N and measured using tensioner device and robot (JLR) in group R. The evaluations were performed at a flexion of 10°, 30°, 60° and 90°. Joint laxities evaluated by the different tools were compared in both groups. No significant between-group differences were observed for JLTs at each flexion angle in both compartments. The JLTs of were larger than JLNs at 90°. The JLTs were larger than JLRs at 30°, 60°and 90°. At a knee flexion angle of 60°, the difference between JLTs and JLRs were larger than that between JLTs and JLNs. The JLTs were smaller than JLNs at 60°and 90°in the lateral compartment. Joint laxities evaluated using the tensioner device with a distraction force of 80 N for both compartments were similar to those evaluated with the robot and the navigation in extension position. However joint laxities evaluated using the tensioner device were larger than those evaluated with robot and the navigation in flexion position.