Posterior condylar offset influences the intraoperative soft tissue balance during posterior-stabilized total knee arthroplasty.

PURPOSE: This study aimed to clarify the influence of the posterior condylar offset (PCO) on intraoperative soft tissue balance including the joint component gap and varus ligament balance measured by an offset-type tensor during posterior-stabilized (PS) total knee arthroplasty (TKA).

METHODS: In this study, 35 patients with osteoarthritis of the knee underwent PS TKA. Intraoperative soft tissue balance including the joint component gap and varus/valgus ligament balance were assessed at 0°, 10°, 45°, 90°, and 135° of flexion with an offset-type tensor that could be used with the femoral component placement and patellofemoral joint reduction. The correlations between the postoperative PCO and the intraoperative soft tissue balance parameters were assessed using simple regression analysis.

RESULTS: The joint component gap at 0° extension was inversely correlated with the PCO (R = -0.41, p < 0.05). The joint component gap of 10°-0° was positively correlated with the PCO (R = 0.35, p < 0.05). No other soft tissue balance parameters were correlated with the PCO.

CONCLUSIONS: A larger PCO was confirmed to reduce joint component gap in extension but not always in flexion in PS TKA.