Background:Injuries of the superficial medial collateral ligament (sMCL) and anteromedial structures of the knee result in excess valgus rotation and external tibial rotation (ER) as well as tibial translation.Purpose:To evaluate a flat reconstruction of the sMCL and anteromedial structures in restoring knee kinematics in the combined MCL- and anteromedial-deficient knee.Study Design:Controlled laboratory study.Methods:Eight cadaveric knee specimens were tested in a 6 degrees of freedom robotic test setup. Force-controlled clinical laxity tests were performed with 200 N of axial compression in 0°, 30°, 60°, and 90° of flexion: 8 N·m valgus torque, 5 N·m ER torque, 89 N anterior tibial translation (ATT) force, and an anteromedial drawer test consisting of 89 N ATT force under 5 N·m ER torque. After determining the native knee kinematics, we transected the sMCL, followed by the deep medial collateral ligament (dMCL). Subsequently, a flat reconstruction of the sMCL with anteromedial limb, mimicking the function of the anteromedial corner, was performed. Mixed linear models were used for statistical analysis ( P < .05).Results:Cutting of the sMCL led to statistically significant increases in laxity regarding valgus rotation, ER, and anteromedial translation in all tested flexion angles ( P < .05). ATT was significantly increased in all flexion angles but not at 60° after cutting of the sMCL. A combined instability of the sMCL and dMCL led to further increased knee laxity in all tested kinematics and flexion angles ( P < .05). After reconstruction, the knee kinematics were not significantly different from those of the native state.Conclusion:Insufficiency of the sMCL and dMCL led to excess valgus rotation, ER, ATT, and anteromedial tibial translation. A combined flat reconstruction of the sMCL and the anteromedial aspect restored this excess laxity to values not significantly different from those of the native knee.Clinical Relevance:The presented reconstruction might lead to favorable results for patients with MCL and anteromedial injuries with an anteromedial rotatory knee instability.

中文翻译：

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内侧副韧带和内侧结构的平面重建恢复了天然膝关节运动学：生物力学机器人研究


背景： 膝关节浅表内侧副韧带 （sMCL） 和前内侧结构损伤导致过度外翻旋转和胫外旋 （ER） 以及胫骨平移。目的： 评价 sMCL 和前内侧结构的平坦重建在恢复 MCL 和前内侧联合缺损膝关节运动学方面的效果。研究设计： 对照实验室研究。方法： 在 6 自由度机器人测试装置中测试 8 例尸体膝关节标本。在 0°、30°、60° 和 90° 屈曲中以 200 N 轴向加压进行力控临床松弛度测试：8 N·m 外翻扭矩、5 N·m ER 扭矩、89 N 胫骨前平移 （ATT） 力，以及由 89 N ATT 力组成的前内侧抽屉试验在 5 N·m ER 扭矩下。在确定了天然膝关节运动学后，我们横切了 sMCL，然后横切了深内侧副韧带 （dMCL）。随后，进行了具有前内侧肢的 sMCL 平面重建，模拟前内侧角的功能。采用混合线性模型进行统计分析 （ P < .05）。结果： 在所有测试的屈曲角度中，sMCL 的切割导致外翻旋转、 ER 和前内侧平移的松弛度在统计学上显着增加 （ P < .05）。切割 sMCL 后，所有屈曲角度的 ATT 均显著增加，但在 60° 处未增加。sMCL 和 dMCL 的联合不稳定性导致所有测试的运动学和屈曲角度的膝关节松弛度进一步增加 （P < .05）。重建后，膝关节运动学与原生状态的运动学没有显著差异。结论： sMCL 和 dMCL 不足导致过度外翻旋转、 ER、ATT 和胫骨前内侧平移。 sMCL 和前内侧的联合平坦重建将这种过度松弛恢复到与天然膝关节没有显着差异的值。临床相关性： 所提出的重建可能为前内侧旋转膝关节不稳定的 MCL 和前内侧损伤患者带来良好的结果。