Department of Orthopaedic Surgery, National University of Singapore, Singapore.
J Biomech. 2010 Jul 20;43(10):2010-6. doi: 10.1016/j.jbiomech.2010.02.036. Epub 2010 Apr 15.
Post-traumatic knee osteochondral injuries are often coupled with anterior cruciate ligament (ACL) injury mechanisms during landing. However, it is not well understood whether restraining axial tibial rotation during landing would influence the extent and distribution of osteochondral disruption. Using ski landing as an example, this study subjected knee specimens to simulated landing impact without and with axial tibial rotation restraint, and investigated the extent and distribution of osteochondral disruption at the tibial plateau. Twenty-one porcine knee specimens were randomly divided into three test conditions, namely: (1) control, (2) impact only (I), and 3) impact with restraint (IR). Simulated landing impact was applied to the specimens based on a single 10 Hz haversine. Osteochondral explants were obtained from anterior, middle and posterior regions of medial and lateral tibial compartments. The extent of cartilage and trabecular disruption in these explants was examined based on histology, SEM and microCT. Only specimens in unrestrained condition incurred ACL failure upon impact. Restraining axial tibial rotation during simulated impact generally inflicted cartilage damage and deformation, and further caused trabecular disruption. Axial tibial rotation restraint did not necessarily restrict anterior tibial translation, as indicated by the presence of relative posterior femoral translation and osteochondral disruption at anterior-posterior tibial regions. While the results obtained in the current study may not be completely translatable to human models, there is likelihood that restraining axial tibial rotation during landing may help to prevent ACL failure, but will also induce osteochondral disruption in most tibial regions.
创伤后膝关节骨软骨损伤通常与落地时前交叉韧带（ACL）损伤机制有关。然而，目前尚不清楚在落地时限制胫骨轴向旋转是否会影响骨软骨破坏的程度和分布。本研究以滑雪落地为例，对膝关节标本进行了模拟落地冲击试验，分别在有和没有胫骨轴向旋转限制的情况下进行，并研究了胫骨平台骨软骨破坏的程度和分布。21 个猪膝关节标本随机分为三组测试条件，分别为：（1）对照组；（2）仅冲击组（I）；（3）冲击加限制组（IR）。根据单个 10 Hz 正弦波，对标本施加模拟落地冲击。从前、中、后三个部位获得内侧和外侧胫骨间室的骨软骨碎片。根据组织学、SEM 和微 CT 检查这些碎片中软骨和小梁破坏的程度。只有在不受限制的情况下，冲击才会导致 ACL 失效。在模拟冲击过程中限制胫骨轴向旋转通常会造成软骨损伤和变形，并进一步导致小梁破坏。胫骨轴向旋转限制并不一定限制胫骨的前向平移，因为存在相对的股骨向后平移和胫骨前-后区域的骨软骨破坏。虽然本研究的结果可能不完全适用于人体模型，但在落地时限制胫骨轴向旋转可能有助于预防 ACL 失效，但也会导致大多数胫骨区域的骨软骨破坏。
