King G J, Damson E L, Frank C B, Shrive N G
Joint Injury and Arthritis Research Group, University of Calgary, Alberta, Canada.
J Biomech Eng. 1995 Feb;117(1):41-7. doi: 10.1115/1.2792268.
In order to study the effect of intra-operative tensioning on the laxity and strength of healing ligament grafts in an animal model, a method of quantifying graft tension was needed. In this study a sensitive ligament tensioning device was developed to measure accurately the prefixation loads in the rabbit medial collateral ligament (MCL) graft. To verify that reproducible changes in ligament tension could be created with the tensioning device, a group of animals had their MCL grafts replaced at one of three different graft loads (tight, anatomic, or loose). The tensioning device consists of two posts which move relative to one another by means of an axial screw. The movable post, which is inserted into the tibial bone island of the MCL graft has a series of strain gauges which can measure the tension applied to the graft. The stationary post attaches to the tibial shaft, permitting the ligament graft to be tensioned relative to this fixed point. After graft tensioning and fixation, the animals were euthanized immediately postoperatively and their ligament load-deformation behavior was measured using an Instron materials testing machine. Specific measures of low load behavior was taken to quantify ligament laxity. Our results demonstrate that the tensioning device was capable of reproducibly altering prefixation graft load intra-operatively as well as MCL laxity immediately postoperatively. A baseline of laxity values was thus developed to follow changes in this laxity measure for future studies of MCL graft healing in this model.
为了在动物模型中研究术中张紧对愈合韧带移植物松弛度和强度的影响，需要一种量化移植物张力的方法。在本研究中，开发了一种灵敏的韧带张紧装置，以准确测量兔内侧副韧带（MCL）移植物的预固定负荷。为了验证使用张紧装置能否产生可重复的韧带张力变化，一组动物的MCL移植物在三种不同的移植物负荷（紧、解剖学或松）之一的情况下进行置换。张紧装置由两个通过轴向螺杆相对移动的柱组成。插入MCL移植物胫骨骨岛的可移动柱有一系列应变片，可测量施加在移植物上的张力。固定柱连接到胫骨干，使韧带移植物相对于这个固定点进行张紧。在移植物张紧和固定后，动物在术后立即安乐死，并使用英斯特朗材料试验机测量其韧带负荷-变形行为。采取低负荷行为的具体测量方法来量化韧带松弛度。我们的结果表明，张紧装置能够在术中可重复地改变预固定移植物负荷以及术后立即改变MCL松弛度。因此建立了一个松弛度值基线，以便在该模型中对MCL移植物愈合的未来研究中跟踪该松弛度测量的变化。
