The use of a robotic system for the determination and assessment of the 3-bundle ACL reconstruction

本研究采用A6-DOF机器人系统确定和评估3束ACL重建技术。在机器人系统对人体尸体膝关节标本施加前后力的过程中，记录了膝关节标本的三维运动和受力/力矩。在前交叉韧带（ACL）的前内侧束被切除后，记录的三维运动被复制到膝关节标本上，同时记录施加在解剖膝关节上的力/力矩。在分离中间束和后外侧束后重复同样的步骤。根据叠加原理，确定了三束所受的力。然后采用腘绳肌腱移植模拟三束前交叉韧带重建技术，对截断的前交叉韧带进行手术重建。通过将三个力传感器连接到移植物上，确定前交叉韧带移植物所承受的力对膝关节标本的外部载荷的响应。此外，确定了acl重建膝关节的三维运动。采用2束前交叉韧带重建技术的膝关节标本重复相同的步骤。结果显示，当总移植物的初始张力为12N时，三束和双束重建膝关节的AP松弛度与完整的AP松弛度相匹配。当初始张力为12N时，三束重建膝关节屈曲角度大于60度时，AP松弛度更接近于完整水平。此外，与双束重建膝关节相比，三束重建膝关节的全移植物所承受的力更小。提示三束ACL重建可能优于传统的单束ACL重建和双束ACL重建。

A6-DOF robotic system was utilized for the determination and assessment of the 3-bundle ACL reconstruction technique in the present study. During the anterior and posterior force was applied to the human cadaveric knee specimens using the robotic system, the 3-dimensional motion, and force/moment applied to, the knee specimen were recorded. After the anteromedial bundle of the anterior cruciate ligament (ACL) was fransected the recorded 3-dimensional motion was reproduced to the knee specimen while the force/moment applied to the dissected knee were recorded. The same procedure was repeated after the dissection of the intermediate bundle and then the dissection of the posterolateral bundle. Under the principle of superposition, the forces carried by the three bundles were determined. Then the transected ACL was surgically reconstructed by simulating the 3-bundle ACL reconstruction technique using hamstring tendon grafts. Using three force transducers attached to the grafts, the forces carried by the ACL grafts were determined in response to externally applied loads to the knee specimen. In addition, the 3-dimensional motion of the ACL-reconstructed knee was determined. The same procedure was repeated for the knee specimen subjected to the 2-bundle ACL reconstruction technique. Results revealed that the AP laxity of both the triple bundle-and double bundle-reconstructed knee were matched to the intact AP laxity when the initial tension of the total grafts was set 12N. When the initial tension was 12N, the AP laxity was closer to intact level in the triple bundle-reconstructed knee in flexion angles higher than 60 degree. Moreoveg the force carried by the total grafts was lower in the triple bundle-reconstructed knee as compared with double bundle-reconstructed knee. It was suggested that the triple bundle ACL reconstruction may be superior to the traditional single bundle ACL reconstruction as well as the double bundle ACL reconstruction.