Anatomic Single Bundle Anterior Cruciate Ligament Reconstruction by Low Accessory Anteromedial Portal Technique: An In Vivo 3D CT Study

Lee, Kwang Won; Hwang, Yoon Sub; Chi, Yong Joo; Yang, Dae Suk; Kim, Ha Yong; Choy, Won Sik

Abstract

PURPOSE
Proper femoral tunnel position is important for anatomical reconstruction of the anterior cruciate ligament (ACL). The purpose of this study was to evaluate the positions of femoral and tibial tunnels created using an accessory anteromedial portal technique in single bundle ACL reconstruction.
MATERIALS AND METHODS
The femoral tunnel was targeted at the mid-portion of the ACL bundles. We evaluated postoperative computed tomography scans of 32 patients treated by ACL reconstruction using a free-hand low accessory anteromedial portal technique. On the tibial side, the tunnel position was evaluated using Tsukada's method. On the femoral side, the position was evaluated using 1) the quadrant method, 2) Mochizuki's method, 3) Mochizuki's method, and 4) Takahashi's method. Tunnel obliquity was also evaluated.
RESULTS
The mean tibial tunnel position was located at 44.6%+/-2.5% anterior from the anterior margin and 48.0%+/-3.0% in medial from the medial margin. The mean femoral tunnel position was located at the center between the anteromedial and posterolateral bundles: Quadrant method, 26.7%+/-2.7%/30.0%+/-2.9%; Watanabe's method, 37.7%+/-2.5%/26.6%+/-2.2%; Mochizuki's method, 38.7%+/-2.7%; Takahashi's method, 21.8%+/-2.2%. The mean femoral tunnel obliquity was 57.7degrees+/-6.2degrees in the sagittal plane and 49.9degrees+/-5.6degrees in the coronal plane.
CONCLUSIONS
In anatomic single bundle ACL reconstruction, the low anteromedial portal technique can restore accurate position of the native footprint. Accurate femoral tunnel position facilitates recovery of stability and decreases graft failure rate.