Daneshvarhashjin Nazanin, Chizari Mahmoud, Javad Mortazavi S M, Rouhi Gholamreza
Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran; Institute for Orthopaedic Research and Training, Department of Biomedical Science, Faculty of Medicine, Katholieke Universiteit Leuven, Leuven, Belgium.
Faculty of Mechanical Engineering, Sharif University of Technology, Tehran, Iran; Engineering Department, School of Physics, Engineering & Computer Sciences, University of Hertfordshire, Hatfield, UK.
J Biomech. 2022 Apr;135:111031. doi: 10.1016/j.jbiomech.2022.111031. Epub 2022 Mar 4.
Although the anterior cruciate ligament (ACL) reconstruction using interference screw is a well-accepted surgical procedure, patients still suffer graft failure in the initial rehabilitation phase. Graft fixation stability of a newly designed anatomical hybrid thread tapered interference screw (AHTTIS) was compared with a conventional standard one (CSIS) by conducting in-vitro mechanical tests. According to the CSIS manufacturer's instruction, eight tapered bone tunnels, matching AHTTIS geometry, and eight straight cylindrical tunnels were drilled in artificial bone blocks. Bovine tendon grafts were fixed using AHTTIS and CSIS in their corresponding bone tunnels. Each graft was subjected to a pre-load, a dynamic cyclic sinusoidal tensile load, and a tensile pullout load. Aggregate graft displacement relative to the bone tunnel under dynamic cyclic load, load corresponding to a 3 mm displacement; load and displacement at yield and ultimate failure of the graft; and graft-bone-screw stiffness resulted from pullout tests were recorded. There were no significant differences between recorded parameters of the two groups, except the graft displacements relative to the bone tunnel at ultimate failure load (8.35 ± 3.03 mm versus 5.28 ± 1.37 mm) and at the yield point (7.73 ± 3.02 mm versus 4.59 ± 1.25 mm) (P < 0.05), which were both significantly greater for the AHTTIS group. Considering all tests were made in the worst-case scenario of fixation of an interference screw, i.e., the employed synthetic bone just mimicked cancellous bone, graft fixation with the AHTTIS is practical. However, in the case of employing high strain rate loads on AHTTIS, further considerations are needed to reduce the side effect of slippage of the graft.
尽管使用挤压螺钉进行前交叉韧带（ACL）重建是一种广泛认可的外科手术，但患者在初始康复阶段仍会出现移植物失败的情况。通过进行体外力学测试，将一种新设计的解剖型混合螺纹锥形挤压螺钉（AHTTIS）的移植物固定稳定性与传统标准挤压螺钉（CSIS）进行了比较。根据CSIS制造商的说明，在人工骨块上钻出八个与AHTTIS几何形状匹配的锥形骨隧道和八个直圆柱形隧道。将牛肌腱移植物分别用AHTTIS和CSIS固定在相应的骨隧道中。对每个移植物施加预载荷、动态循环正弦拉伸载荷和拉伸拔出载荷。记录动态循环载荷下相对于骨隧道的总移植物位移、对应于3毫米位移的载荷、移植物屈服和最终失效时的载荷和位移，以及拔出试验产生的移植物-骨-螺钉刚度。两组记录参数之间无显著差异，但在最终失效载荷（8.35±3.03毫米对5.28±1.37毫米）和屈服点（7.73±3.02毫米对4.59±1.25毫米）时相对于骨隧道的移植物位移除外（P<0.05），AHTTIS组的这两个位移均显著更大。考虑到所有测试均在挤压螺钉固定的最坏情况下进行，即使用的合成骨仅模拟松质骨，AHTTIS固定移植物是可行的。然而，在对AHTTIS施加高应变率载荷的情况下，需要进一步考虑以减少移植物滑动的副作用。
