Soft-tissue balancing in total knee arthroplasty: cruciate-retaining versus posterior-stabilised, and measured-resection versus gap technique
Matsumoto, T., Muratsu, H., Kawakami, Y. et al.Knee
Purpose
The purpose of this study was to prove the hypothesis that soft tissues are well balanced using the gap technique with a navigation system in cruciate-retaining (CR) and posterior-stabilised (PS) total knee arthroplasty (TKA), leading to better clinical outcomes compared with the measured-resection technique.
Methods
One hundred and thirty-five TKAs (90 CR and 45 PS) were performed in patients with varus-type osteoarthritis using the gap technique guided by the offset-type tensor and a navigation system. Soft-tissue balance (joint-component gap and ligament balance) were intraoperatively assessed with the tensor under 40 lb of joint-distraction force. The achievement in the equalised rectangular gap at extension and flexion was assessed and retrospectively compared with the previous series in which the measured-resection technique was used (20 CR and 100 PS TKAs). In addition, clinical outcomes, including range of motion and Knee Society Score were assessed at a minimum two year follow-up.
Results
In achieving equalised rectangular gaps at extension and flexion, CR TKAs met criteria in more cases [66.7 % (64/90) vs. 44.4 % (20/45) of PS TKA] with the gap technique, which was superior to that with the measured-resection technique [50.0 % (10/20) of CR TKA and 28.0 % (28/100) of PS TKA]. However, clinical outcomes showed no significant differences among groups at minimum two year follow-up.
Conclusions
The superiority of CR TKA with the gap technique in achieving equalised rectangular gaps at extension and flexion does not directly reflect two year postoperative clinical outcomes.
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