Kano Toshiya, Ishikawa Masakazu, Ogawa Yuki, Akebono Hiroyuki, Sugeta Atsushi, Ohmi Masato, Kamei Goki, Nakamae Atsuo, Adachi Nobuo
Dept. of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Dept. of Artificial Joints and Biomaterials, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Asia Pac J Sports Med Arthrosc Rehabil Technol. 2022 Jul 31;30:1-8. doi: 10.1016/j.asmart.2022.05.003. eCollection 2022 Oct.
Anterior cruciate ligament (ACL) injury is the most common traumatic injury to the knee joint. Suspensory fixation has become popular in ACL reconstruction because of its high primary stability, less invasiveness, and surgical convenience. There are two common types of suspensory fixation devices: those with fixed-length and those with adjustable-length loops. Owing to structural differences and differences in initial tensioning techniques, it is expected that mechanical property and damage to the tendons will vary from device to device; however, no literature has examined this so far. The main purpose of this study was to evaluate the damage caused to the tendon by three different suspensory fixation devices. An effective mechanical test was carried out as a prerequisite.
First, the mechanical properties of simple loop device (SLD) as fixed-length loop device, first-generation, and second-generation adjustable devices (AD1 and AD2) as adjustable-length loop devices were tested (isolated device testing). Second, each device was tested using bovine extensor tendons (specimen testing). Cyclic testing included 2000 cycles; the devices were subsequently displaced until failure, and the ultimate tensile strength was determined using isolated device testing. Six samples of 3 devices were used in each testing experiment. After specimen testing, the surface structure of the tendon was evaluated quantitatively using optical coherence tomography (OCT) and our original histological scoring system.
During isolated device testing, SLD demonstrated the least cyclic displacement, followed by AD1 and AD2. The highest ultimate tensile strength was observed in AD2, followed by SLD and AD1. In specimen testing, the least cyclic displacement was observed in SLD, followed by AD1 and AD2. Histologically, AD1 demonstrated a significantly lower score, with damaged surface morphology, than SLD and AD2. OCT values were significantly higher, with a more disturbing tendon surface structure, in AD1 than in SLD and AD2.
The first-generation adjustable loop device exhibited greatest graft tissue damage at the suspensory site in a clinically relevant setting. The thinner adjustable loop mechanism may have elevated graft damage by frictional stresses during loop adjustment or by repetitive tensioning stresses.
前交叉韧带（ACL）损伤是膝关节最常见的创伤性损伤。悬吊固定因其初始稳定性高、侵入性小和手术便利性，在ACL重建中已变得流行。悬吊固定装置有两种常见类型：固定长度型和可调节长度环型。由于结构差异和初始张紧技术的不同，预计不同装置的力学性能和对肌腱的损伤会有所不同；然而，目前尚无文献对此进行研究。本研究的主要目的是评估三种不同悬吊固定装置对肌腱造成的损伤。作为前提条件，进行了有效的力学测试。
首先，测试了作为固定长度环装置的简单环装置（SLD）以及作为可调节长度环装置的第一代和第二代可调节装置（AD1和AD2）的力学性能（孤立装置测试）。其次，使用牛伸肌腱对每个装置进行测试（样本测试）。循环测试包括2000个周期；随后将装置移位直至失效，并使用孤立装置测试确定极限拉伸强度。每个测试实验使用每种装置的六个样本。样本测试后，使用光学相干断层扫描（OCT）和我们原有的组织学评分系统对肌腱的表面结构进行定量评估。
在孤立装置测试中，SLD的循环位移最小，其次是AD1和AD2。AD2的极限拉伸强度最高，其次是SLD和AD1。在样本测试中，SLD的循环位移最小，其次是AD1和AD2。组织学上，AD1的评分明显低于SLD和AD2，其表面形态受损。AD1的OCT值明显高于SLD和AD2，肌腱表面结构更紊乱。
在临床相关环境中，第一代可调节环装置在悬吊部位对移植组织造成的损伤最大。较薄的可调节环机制可能因环调节过程中的摩擦应力或反复张紧应力而增加了移植组织的损伤。
