Evaluating for Tunnel Convergence in Anterior Cruciate Ligament Reconstruction With Modified Lemaire Tenodesis: What...

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiology

Background:

• Combined anterior cruciate ligament (ACL) reconstruction and anterolateral tenodesis (ALT) are common orthopedic procedures.
• Femoral fixation of the ALT graft can potentially interfere with the ACL tunnel, leading to complications.
• Understanding tunnel proximity and collision is crucial for successful surgical outcomes.

Purpose of the Study:

• To analyze postoperative computed tomography (CT) scans of patients who underwent combined ACL reconstruction and modified Lemaire ALT.
• To evaluate the spatial relationship between the ACL and ALT femoral tunnels.
• To identify factors influencing tunnel collision and proximity.

Main Methods:

• Prospective evaluation of postoperative CT scans from 52 patients.
• Measurement of tunnel convergence, shortest distance, and inclination (axial and coronal planes).
• Analysis of measurements at cortical and deeper planes within the lateral condyle.

Main Results:

• No tunnel convergence at the cortical level.
• 15.4% of cases showed tunnel collision, and 21.1% had a bone bridge <5mm at the deeper plane.
• An axial inclination <15° correlated with collision (P < .001), while >20° prevented collision (P < .001).

Conclusions:

• Drilling the ALT femoral tunnel with an inclination of at least 20° anteriorly is recommended.
• This inclination helps avoid interference with the anatomic ACL femoral tunnel.
• Optimizing tunnel placement can prevent complications in combined ACL reconstruction and ALT.