From the Research
The proper position of the tibial tunnel in ACL reconstruction should be placed in the center of the native ACL footprint, typically 7-8 mm anterior to the posterior cruciate ligament (PCL) and slightly medial to the midline of the intercondylar notch, as supported by the most recent study 1.
Key Considerations
- The tunnel should exit the tibial plateau at approximately a 45-55 degree angle relative to the tibial shaft in the sagittal plane.
- Anatomically, this corresponds to a position that is roughly 40-50% of the anteroposterior diameter of the tibia from the anterior edge.
- The ideal position avoids both anterior placement, which can cause graft impingement against the intercondylar roof during knee extension, and posterior placement, which can result in a vertically oriented graft with poor rotational control.
Importance of Accurate Placement
- Proper tibial tunnel positioning is critical because it directly affects graft isometry, knee kinematics, and long-term outcomes.
- If the tunnel is placed too anteriorly, it may lead to limited knee extension and graft failure, while a tunnel that is too posterior may result in inadequate rotational stability.
Recommended Techniques
- Surgeons should use anatomical landmarks, fluoroscopic guidance, or navigation systems during the procedure to ensure accurate tunnel placement, as suggested by 2 and 1.
- The use of a novel grid and biplanar stereoradiographic imaging can provide a precise and reproducible description of the tibial tunnel placement, as described in 1.
Additional Considerations
- The location of the tibial spine can influence tibial tunnel placement, and confirmation of the ACL footprint is required to create accurate anatomical tunnels during surgery, as noted in 3.
- In cases of multiligamentous reconstruction, the risk of tunnel convergence should be considered, and meniscus root repair tunnels should be reoriented to be parallel to the ACL tunnel to decrease the risk of convergence, as recommended in 4.