Department of Orthopaedic Surgery, University of Minnesota Medical School, 2450 Riverside Avenue, R200, Minneapolis, MN 55454, USA.
Am J Sports Med. 2010 Mar;38(3):550-7. doi: 10.1177/0363546509348742. Epub 2010 Jan 23.
Ligament restraints to terminal knee extension are poorly understood.
(1) As with other motions of the knee, genu recurvatum is limited primarily by a named, identifiable structure. (2) As the largest static structure of the posterior knee, the oblique popliteal ligament is uniquely suited to act as a checkrein to knee hyperextension.
Descriptive laboratory study.
Twenty fresh-frozen human knees were divided into 3 groups for a ligament sectioning study. Extension moments of 14 and 27 N x m were applied before and after sectioning of each ligament, and motion changes were recorded. In group 1, the oblique popliteal ligament was sectioned first, followed by the fabellofibular ligament, ligament of Wrisberg, anterior cruciate ligament, posterolateral structures, and posterior cruciate ligament. In group 2, the order was altered to section the anterior cruciate ligament first; no other changes were made. Similarly, the cutting order for group 3 was altered to section the posterior cruciate ligament first. The sagittal tibial slope of each specimen was documented off a lateral radiograph.
The greatest increase in knee hyperextension was observed after sectioning the oblique popliteal ligament. This was independent of cutting order, consistent across groups, and statistically significant. In all groups, the increase in knee hyperextension after sectioning the oblique popliteal ligament approached or exceeded the increases seen after sectioning the anterior and posterior cruciate ligaments combined. Overall, less knee hyperextension was seen in knees with increased posterior tibial slope.
The oblique popliteal ligament was found to be the primary ligamentous restraint to knee hyperextension.
Further studies are needed to determine if surgical repair or reconstruction of the oblique popliteal ligament can restore normal motion limits in patients with symptomatic genu recurvatum. Patients with decreased posterior tibial slope would have increased recurvatum with posterior structure injury, which increases the likelihood of increased symptoms in this population.
膝关节伸直末端的韧带限制作用尚未被充分了解。
（1）与膝关节的其他运动一样，膝过伸主要受一个已命名、可识别的结构限制。（2）作为膝关节后部最大的静态结构，斜向腘韧带非常适合作为防止膝关节过伸的缰绳。
描述性实验室研究。
20 个新鲜冷冻的人膝关节被分为 3 组进行韧带切断研究。在切断每根韧带之前和之后，应用 14 和 27 N·m 的伸展力矩，并记录运动变化。在第 1 组中，首先切断斜向腘韧带，然后切断腓肠外侧副韧带、Wrisberg 韧带、前交叉韧带、后外侧结构和后交叉韧带。在第 2 组中，改变顺序，首先切断前交叉韧带；没有其他改变。同样，第 3 组的切断顺序也改为首先切断后交叉韧带。每个标本的矢状胫骨倾斜度都记录在外侧 X 线片上。
切断斜向腘韧带后，膝关节过伸的增加最大。这与切断顺序无关，在各组中一致，且具有统计学意义。在所有组中，切断斜向腘韧带后膝关节过伸的增加接近或超过了切断前交叉韧带和后交叉韧带后观察到的增加。总体而言，胫骨后斜率增加的膝关节过伸程度较小。
斜向腘韧带是膝关节过伸的主要韧带限制结构。
需要进一步研究以确定是否可以通过修复或重建斜向腘韧带来恢复有症状的膝过伸患者的正常运动限制。胫骨后斜率降低的患者在后部结构损伤时会出现更大的过伸，这增加了该人群症状加重的可能性。
