Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street-GRJ 1215, Boston, MA 02114, USA.
Knee Surg Sports Traumatol Arthrosc. 2011 May;19(5):712-8. doi: 10.1007/s00167-010-1319-6. Epub 2010 Nov 17.
This paper investigated the effect of graft fixation sequence on knee joint biomechanics after a double-bundle ACL reconstruction.
Two independently published biomechanical studies that investigated the biomechanics of double-bundle ACL reconstructions using similar robotic testing systems were compared. In each study, ten human cadaveric knees were tested under three different conditions: intact, ACL deficient, and ACL reconstructed using a double-bundle technique with the anteromedial (AM) graft fixed at 60° of flexion and the posterolateral (PL) graft fixed at full extension. In one study (Study A), the AM graft was fixed first; while in another study (Study B), the PL graft was fixed first. Knee kinematics, in situ forces of the ACL and the ACL grafts were measured under two loading conditions: an anterior tibial load of 134 N and a combined tibial torques (10 N·m valgus and 5 N·m internal tibial torques) in both studies.
When AM graft was fixed first, the in situ force of the AM graft was lower than the native AM bundle at all flexion angles. The in situ force in the PL graft, however, was higher than the native PL bundle at all flexion angles. When the PL graft was fixed first, the in situ force of the AM graft was higher than the native AM bundle, while the in situ forces of the PL graft were lower than the native PL bundle at all flexion angles. Both studies demonstrated that the double-bundle ACL reconstructions can closely restore the normal knee joint kinematics.
Even though the grafts were fixed using similar initial tensions and at same flexion angles, the sequence of fixing the two grafts in a double-bundle ACL reconstruction could alter the in situ forces in the grafts and affect the knee kinematics. These data imply that in clinical application of a double-bundle ACL reconstruction, the sequence of graft fixation should be an important surgical parameter.
本研究旨在探讨前交叉韧带（ACL）双束重建中移植物固定顺序对膝关节生物力学的影响。
比较了两项独立发表的生物力学研究，这两项研究均使用类似的机器人测试系统，研究了 ACL 双束重建的生物力学。在每项研究中，10 个人体尸体膝关节在三种不同条件下进行了测试：完整、ACL 缺失和 ACL 重建（使用双束技术，前内侧（AM）移植物在 60°屈曲时固定，后外侧（PL）移植物在完全伸展时固定）。在一项研究（研究 A）中，先固定 AM 移植物；而在另一项研究（研究 B）中，先固定 PL 移植物。在两种加载条件下测量膝关节运动学、ACL 和 ACL 移植物的原位力：在两项研究中，前胫骨加载 134 N 和胫骨组合扭矩（10 N·m 外翻和 5 N·m 内胫骨扭矩）。
当先固定 AM 移植物时，在所有屈曲角度下，AM 移植物的原位力均低于原生 AM 束。然而，在所有屈曲角度下，PL 移植物的原位力均高于原生 PL 束。当先固定 PL 移植物时，在所有屈曲角度下，AM 移植物的原位力均高于原生 AM 束，而 PL 移植物的原位力均低于原生 PL 束。两项研究均表明，ACL 双束重建可以很好地恢复正常膝关节运动学。
即使使用相似的初始张力和相同的屈曲角度固定两个移植物，在 ACL 双束重建中固定两个移植物的顺序也可以改变移植物的原位力并影响膝关节运动学。这些数据表明，在 ACL 双束重建的临床应用中，移植物固定的顺序应该是一个重要的手术参数。
