Laprade Robert F, Engebretsen Lars, Johansen Steinar, Wentorf Fred A, Kurtenbach Chad
Department of Orthopaedic Surgery, University of Minnesota, 2450 Riverside Avenue, R200, Minneapolis, MN 55454, USA.
Am J Sports Med. 2008 May;36(5):956-60. doi: 10.1177/0363546507312380. Epub 2008 Jan 28.
Increased stability of posterolateral corner knee injuries has been observed clinically after proximal tibial medial opening wedge osteotomies.
Static varus and external rotatory stability will be significantly improved in a knee with a grade 3 posterolateral knee injury after a proximal tibial medial opening wedge osteotomy.
Controlled laboratory study.
Biomechanical testing of 10 nonpaired, cadaveric knees was performed in the intact state, after transection of the posterolateral corner (fibular collateral ligament, popliteus tendon, and popliteofibular ligament), and after a 10-mm proximal tibial medial opening wedge osteotomy. Loading conditions consisted of 12 N.m varus moments and 6 N.m external rotation torques. Six degrees of freedom motion analysis was used to assess motion changes, and a buckle transducer was used to measure the force on the superficial medial collateral ligament during applied loads.
After transection of the posterolateral corner structures, a significant increase in varus rotation was found to applied varus moments with a mean increased opening of 5.9 degrees to varus stress at 30 degrees and 5.8 degrees at 90 degrees of knee flexion. After proximal tibial medial opening wedge osteotomy, varus rotation was increased by a mean of 1.6 degrees at 30 degrees and 1.7 degrees at 90 degrees of knee flexion compared with the intact state. There was a significant decrease in varus rotation to a varus moment after osteotomy compared with the posterolateral sectioned state at both 30 degrees and 90 degrees . External rotation of the knee increased by 4.7 degrees at 30 degrees and 4.8 degrees at 90 degrees after posterolateral structure sectioning compared with the intact state. After the osteotomy, there was a significant decrease in external rotation compared with the posterolateral sectioned state, and there was no significant difference in external rotation compared with the intact state. There was a significant increase in force on the superficial medial collateral ligament after the osteotomy compared with both the intact and posterolateral corner cut state for both an applied varus moment and external rotation torque at both 30 degrees and 90 degrees .
Our results demonstrate that a proximal tibial medial opening wedge osteotomy decreased varus and external rotation laxity for posterolateral corner-deficient knees. Concurrently, an increase in force was observed on the superficial medial collateral ligament compared with the native state.
The improved stability observed in some patients with grade 3 posterolateral knee injuries after a proximal tibial medial opening wedge osteotomy appears to at least in part be due to tightening of the superficial medial collateral ligament. The long-term consequences of the increased force on the superficial medial collateral ligament on the medial compartment, and whether it elongates with time, merit further investigation.
临床上观察到，胫骨近端内侧开放楔形截骨术后，膝关节后外侧角损伤的稳定性有所提高。
胫骨近端内侧开放楔形截骨术后，三级膝关节后外侧损伤的膝关节在静态内翻和外旋稳定性方面将得到显著改善。
对照实验室研究。
对10个非配对的尸体膝关节进行生物力学测试，测试状态分别为完整状态、切断后外侧角（腓侧副韧带、腘肌腱和腘腓韧带）后以及胫骨近端内侧进行10毫米开放楔形截骨术后。加载条件包括12牛·米的内翻力矩和6牛·米的外旋扭矩。使用六自由度运动分析来评估运动变化，并使用扣式传感器测量施加负荷时浅层内侧副韧带上的力。
切断后外侧角结构后，发现施加内翻力矩时内翻旋转显著增加，在膝关节屈曲30度时内翻应力下平均开口增加5.9度，在90度时增加5.8度。与完整状态相比，胫骨近端内侧开放楔形截骨术后，膝关节屈曲30度时内翻旋转平均增加1.6度，90度时增加1.7度。与后外侧切断状态相比，截骨术后在30度和90度时对内翻力矩的内翻旋转均显著降低，但与完整状态相比，外旋无显著差异。与完整状态相比，切断后外侧结构后，膝关节在30度时外旋增加4.7度，90度时增加4.8度。截骨术后与后外侧切断状态相比，外旋显著降低，与完整状态相比，外旋无显著差异。与完整状态和后外侧角切断状态相比，在30度和90度时，施加内翻力矩和外旋扭矩时，截骨术后浅层内侧副韧带上的力均显著增加。
我们的结果表明，胫骨近端内侧开放楔形截骨术可降低后外侧角损伤膝关节的内翻和外旋松弛度。同时，与原始状态相比，浅层内侧副韧带上的力有所增加。
胫骨近端内侧开放楔形截骨术后，部分三级膝关节后外侧损伤患者观察到的稳定性改善似乎至少部分归因于浅层内侧副韧带的收紧。浅层内侧副韧带上力增加对内侧间室的长期影响以及它是否会随时间延长，值得进一步研究。
