Kudo Toshiharu, Tohyama Harukazu, Minami Akio, Yasuda Kazunori
Department of Sports Medicine and Joint Reconstruction Surgery, Hokkaido University School of Medicine, Kita-ku Kita-15 Nishi-7, Sapporo 060-8638, Japan.
Clin Biomech (Bristol). 2005 May;20(4):414-20. doi: 10.1016/j.clinbiomech.2004.11.017. Epub 2005 Jan 25.
The Bone Mulch screw/WasherLoc fixation system has attracted notice because of its possible advantages. The purpose of the present study was to compare the biomechanical properties of this fixation system for the double-looped flexor tendon graft with those of two standard fixation techniques that had been commonly performed in anterior cruciate ligament reconstruction.
Anterior cruciate ligament reconstruction was carried out in each group using one of three different procedures (n=14 for each procedure). For each group, seven femur-graft-tibia complexes underwent submaximal cyclic displacement of 5000 cycles after an initial tension of 20N was applied. Then, tensile testing was performed for the complex at a single position, 45 degrees of knee flexion, in which the longitudinal axis of the graft coincided with the axis of the bone tunnels. The remaining seven complexes in each group were examined in the same tensile test without applying any cyclic displacement.
At the 5000th cycle of the displacement, the peak load of the complex with the Bone Mulch screw/WasherLoc system was significantly higher than that with the Endobutton technique (P<0.0001). After 5000 cycles of displacement, the initial stiffness and the linear stiffness of the complex with the Bone Mulch screw/WasherLoc system were significantly higher than those with the double-looped tendon graft and the Endobutton technique (P<0.0001 for both comparisons), while those with the Bone Mulch screw/WasherLoc system were significantly lower than those with the patellar tendon graft with interference screws (initial stiffness: P=0.0004, linear stiffness: P=0.0007).
The present study has clarified that the Bone Mulch screw/WasherLoc system provides high stiffness to the complex for the double-looped flexor tendon graft.
骨碎粒螺钉/垫圈定位固定系统因其可能具有的优势而受到关注。本研究的目的是比较这种用于双股屈肌腱移植物的固定系统与前交叉韧带重建中常用的两种标准固定技术的生物力学特性。
每组采用三种不同手术方法之一进行前交叉韧带重建（每种手术方法n = 14）。对每组而言，在施加20N的初始张力后，七个股骨-移植物-胫骨复合体进行5000次亚最大循环位移。然后，在膝关节屈曲45度的单一位置对复合体进行拉伸测试，此时移植物的纵轴与骨隧道的轴线重合。每组中其余七个复合体在相同的拉伸测试中不施加任何循环位移进行检查。
在位移的第5000个循环时，采用骨碎粒螺钉/垫圈定位系统的复合体的峰值负荷显著高于采用Endobutton技术的复合体（P < 0.0001）。在5000次循环位移后，采用骨碎粒螺钉/垫圈定位系统的复合体的初始刚度和线性刚度显著高于采用双股肌腱移植物和Endobutton技术的复合体（两种比较均为P < 0.0001），而采用骨碎粒螺钉/垫圈定位系统的复合体的初始刚度和线性刚度显著低于采用带干涉螺钉的髌腱移植物的复合体（初始刚度：P = 0.0004，线性刚度：P = 0.0007）。
本研究阐明了骨碎粒螺钉/垫圈定位系统为双股屈肌腱移植物复合体提供了高刚度。
