Many factors can influence post-operative kinematics after total knee arthroplasty (TKA). These factors include intraoperative surgical conditions such as ligament release or quantity of bone resection as well as differences in implant design. Release of the medial collateral ligament (MCL) is commonly performed to allow correction of varus knee. Precise biomechanical knowledge of the individual components of the MCL is critical for proper MCL release during TKA. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on valgus and rotatory stability in TKA. This study used six fresh-frozen cadaveric knees with intact cruciate ligaments. All TKA procedures were performed by the same surgeon using CR-TKA with a CT-free navigation system. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of flexion. One sequential sectioning sequence was performed on each knee, beginning with femoral arthroplasty only (S1), and thereafter sequentially, medial half tibial resection with spacer (S2), ACL cut (S3), tibial arthroplasty (S4), release of the dMCL (S5), and finally, release of the POL (S6). The same examiner applied all external loads of 10 N-m valgus and 5 N-m internal and external rotation torques at each flexion angle and for each cut state. All data were analyzed statistically using two-way ANOVA and paired t-test. A significant difference was determined to be present for P < .05.Introduction
Materials and Methods
Biomechanical knowledge of the medial collateral ligament (MCL) is important for MCL release during knee arthroplasty. The purpose of this study was to define the influences of the deep medial collateral ligament (dMCL) and the posterior oblique ligament (POL) on valgus and rotatory stability in knee arthroplasty. Six cadaveric knees were divided into 2 groups with unique sequential sectioning sequences of the dMCL and the POL. Group A (n = 2) first received femoral arthroplasty only, and thereafter sequentially received medial half tibial resection with spacer, ACL cut, dMCL cut, POL cut, and finally tibial arthroplasty. Group B (n = 4) first received femoral arthroplasty only, and thereafter sequentially received medial half tibial resection with spacer, ACL cut, tibial arthroplasty, dMCL cut, and finally, POL cut. A CT-free navigation system monitored motion after application of valgus loads (10 N-m) and internal and external rotation torques (5 N-m) at 0°, 20°, 30°, 60°, and 90°of knee flexion.Purpose:
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