Mae Tatsuo, Shino Konsei, Nakata Ken, Toritsuka Yukiyoshi, Otsubo Hidenori, Fujie Hiromichi
Department of Orthopaedic Surgery, Kansai Rosai Hospital, 3-1-69, Inabaso, Amagasaki, Hyogo, 660-8511, Japan.
Am J Sports Med. 2008 Jun;36(6):1087-93. doi: 10.1177/0363546508314433. Epub 2008 Feb 29.
Although anterior cruciate ligament (ACL) reconstructions are frequently performed, little is known about the effect of initial tension on an ACL graft at the time of its fixation.
The objective of this study was to evaluate the effects of initial tension on the relative position and the load between femur and tibia during passive motion.
Controlled laboratory study.
Seven cadaveric knees underwent a passive flexion-extension movement from 0 degrees to 90 degrees with a robotic system developed in the authors' laboratory under 6 degrees of freedom, while their 3-dimensional paths were recorded. A single-socket ACL reconstruction was performed with an autogenous quadrupled hamstring tendon graft, while the knees underwent the same movement as before with the initial graft tension of 22 N (group A), 44 N (group B), or 88 N (group C) at 20 degrees. The relative position between the femur and the tibia was recorded, and the load in the femorotibial joint was calculated using the principle of superposition.
The tibia in group C was most posteriorly positioned among the 3 groups (an average posterior translation of 0.6, 1.3, and 2.6 mm in groups A, B, and C, respectively). The tibia also moved proximally and laterally with external and valgus rotation with an increase in initial tension, and consequently the load in the femorotibial joint increased at all flexion angles.
With an increase in initial tension, the tibia moved posterolaterally with external and valgus rotation, and consequently the contact force in the femorotibial joint increased.
Excessive initial tension at the time of ACL reconstruction may potentially bring deleterious effects to the articular surface, leading to cartilage degeneration.
尽管前交叉韧带（ACL）重建手术经常进行，但对于ACL移植物在固定时初始张力的影响却知之甚少。
本研究的目的是评估初始张力对被动运动期间股骨和胫骨之间相对位置及负荷的影响。
对照实验室研究。
使用作者实验室开发的机器人系统，对7具尸体膝关节进行从0度到90度的被动屈伸运动，运动过程中在6个自由度下记录其三维路径。采用单隧道ACL重建术，使用自体四股绳肌腱移植物，然后膝关节进行与之前相同的运动，在20度时移植物的初始张力分别为22 N（A组）、44 N（B组）或88 N（C组）。记录股骨和胫骨之间的相对位置，并使用叠加原理计算股胫关节的负荷。
C组胫骨在三组中位置最靠后（A组、B组和C组的平均后移分别为0.6、1.3和2.6 mm）。随着初始张力增加，胫骨随着外旋和外翻旋转向近端和外侧移动，因此在所有屈曲角度下股胫关节的负荷均增加。
随着初始张力增加，胫骨随着外旋和外翻旋转向后外侧移动，因此股胫关节的接触力增加。
ACL重建时初始张力过大可能会对关节表面带来有害影响，导致软骨退变。
