Cain E Lyle, Biggers Marcus D, Beason David P, Emblom Benton A, Dugas Jeffrey R
American Sports Medicine Institute, Birmingham, Alabama.
Andrews Sports Medicine and Orthopaedic Center, Birmingham, Alabama.
J Knee Surg. 2017 Nov;30(9):960-964. doi: 10.1055/s-0037-1599251. Epub 2017 Mar 10.
Accurate tunnel placement is important for a successful anterior cruciate ligament (ACL) reconstruction. Controversy exists concerning the preferred method of femoral tunnel preparation, with proponents of both medial portal and transtibial drilling techniques. Current ACL literature suggests that placement of the femoral ACL attachment site posterior or "low" in the ACL footprint leads to more anatomically correct ACL mechanics and better rotational control. There is limited literature focusing on ACL graft displacement through knee range of motion based on specific paired placement of femoral and tibial tunnels. Our purpose was to assess ACL isometry between multiple combinations of femoral and tibial tunnels. We hypothesized that placement of the graft at the posterior aspect of the ACL footprint on the femur would be significantly less isometric and lead to more graft displacement as compared with central or anterior placement. The ACL of matched pairs of cadaveric knees was arthroscopically debrided while leaving the soft tissue footprint on the femur and tibia intact. One knee from each pair underwent notchplasty. In all knees, three femoral and three tibial tunnels were created at the anterior, central, and posterior aspects of the ACL footprint. A suture was passed through each tunnel combination (nine potential pairs), and the change in isometry was measured throughout full knee range of motion. Placement of the femoral tunnel along the posterior aspect of the ACL footprint was less isometric compared with a central or anterior position in the femoral footprint. Placement of a posterior tibial tunnel also led to decreased isometry, but tibial tunnel placement affected isometry to a lesser extent than femoral tunnel placement. The combination of a posterior femoral and posterior tibial tunnel resulted in greater than 1 cm of graft excursion from full flexion to extension. Placement of ACL tunnels at anisometric sites may adversely affect the mechanical properties and behavior of the ACL graft, resulting in either graft laxity in flexion or overconstraint and loss of extension.
准确的隧道定位对于成功进行前交叉韧带（ACL）重建至关重要。关于股骨隧道制备的首选方法存在争议，内侧入路和经胫骨钻孔技术都有支持者。当前的ACL文献表明，将股骨ACL附着点置于ACL足迹的后方或“低位”会导致更符合解剖学的ACL力学和更好的旋转控制。基于股骨和胫骨隧道的特定配对放置，关注ACL移植物在膝关节活动范围内位移的文献有限。我们的目的是评估股骨和胫骨隧道多种组合之间的ACL等长性。我们假设，与中央或前方放置相比，将移植物置于股骨上ACL足迹的后方会明显更不等长，并导致更多的移植物位移。对配对的尸体膝关节的ACL进行关节镜清理，同时保留股骨和胫骨上的软组织足迹。每对膝关节中的一个进行髁间窝成形术。在所有膝关节中，在ACL足迹的前、中、后方面创建三个股骨隧道和三个胫骨隧道。将缝线穿过每个隧道组合（九个潜在配对），并在整个膝关节活动范围内测量等长性的变化。与股骨足迹的中央或前方位置相比，沿着ACL足迹后方面放置股骨隧道的等长性较差。胫骨后隧道的放置也会导致等长性降低，但胫骨隧道放置对等长性的影响程度小于股骨隧道放置。股骨后隧道和胫骨后隧道的组合导致移植物在从完全屈曲到伸展的过程中偏移超过1厘米。将ACL隧道置于不等长部位可能会对ACL移植物的力学性能和行为产生不利影响，导致屈曲时移植物松弛或过度约束以及伸展丧失。
