Femoral tunnel placement in anterior cruciate ligament reconstruction: rationale of the two incision technique

Abstract

Endoscopic anterior cruciate ligament (ACL) reconstruction can be performed through oneincision or two-incision technique. The current one-incision endoscopic ACL single bundle reconstruction techniques attempt to perform an isometric repair placing the graft along the roof of the intercondylar notch, anterior and superior to the native ACL insertion. However the ACL isometry is a theoretical condition, and has not stood up to detailed testing and investigation. Moreover this type of reconstruction results in a vertically oriented non-anatomic graft, which is able to control anterior tibial translation but not the rotational component of the instability. Femoral tunnel obliquity has a great effect on rotational stability. To improve the obliquity of graft, an anatomical ACL reconstruction should be attempt. Anatomical insertion of ACL on the femur lies very low in the notch, spreading between 11 and 9-8 o'clock position and the center lies lower than at 11 o'clock position. Femoral aiming devices through the tibial tunnel aim at an isometric placement, and they do not aim at an anatomic position of the graft. Also, a placement of tunnel in a position of 11 o'clock is unable to restore rotational stability. The two-incision technique, with the possibility to position femoral tunnel independently by tibial tunnel, allows us to place femoral tunnel entrance in a position of 10 'clock that can most accurately reproduce the anatomic behaviour of the ACL and can potentially improve the response of the graft to rotatory loads. This positioning results in a more oblique graft placement, avoiding problem related to PCL impingement during knee flexion. Further studies are required to understand if this kind of reconstruction can ameliorate proprioception as well as clinical outcome at a long-term follow-up.

Biomechanical Evaluation of Pediatric Anterior Cruciate Ligament Reconstruction Techniques

“…Multiple studies have evaluated pediatric patients who were treated nonoperatively after intrasubstance ACL injuries. 8,9,21 These findings were consistent and included decreased levels of activity, recurrent episodes of instability, subsequent meniscal tears, and degenerative changes. Similar studies compared outcomes in nonsurgically versus surgically treated patients and found higher functional outcome scores, fewer episodes of instability, and decreased secondary meniscal tears in the surgically treated groups.…”

Comparison of In Situ Forces and Knee Kinematics in Anteromedial and High Anteromedial Bundle Augmentation for Partially Ruptured Anterior Cruciate Ligament

“…This finding is in accordance with previous studies indicating that the lower graft could better control the rotational stability in single-bundle ACL reconstructions. 15,21,23,26 In this study, the deficient AM knee manifested significant laxity in AP and rotatory stability, when compared with the intact knee, so even with an intact PL bundle the knee's kinematics would still be significantly affected. The AM and PL bundles both function to maintain the knee stability, and one cannot compensate for the loss of the other.…”

The effects of femoral graft placement on in vivo knee kinematics after anterior cruciate ligament reconstruction

“…Achieving anatomic graft placement remains a concern in ACL reconstruction (Bedi 2009; Scanlan 2009; Steiner 2009; Kopf 2010; Scanlan 2010), with studies often citing anterior and proximal placement on the femur as a problem (Kohn 1998; Arnold 2001; Garofalo 2007; Harner 2008; Kaseta 2008; Abebe 2009). This study used biplanar fluoroscopy and MR imaging to compare the effect of graft placement on the ability of ACL reconstruction to restore normal knee motion during a quasi-static lunge.…”