2025 ISAKOS Biennial Congress ePoster
Optimal Anterolateral Ligament Tibial Tunnel Orientation to Minimize Collision with the Anterior Cruciate Ligament Tibial Tunnel and Prevent Saphenous Nerve Injury During Combined Reconstruction
Junhee Cho, MD, Seoul KOREA, REPUBLIC OF
Se-Han Jung, MD, Seoul KOREA, REPUBLIC OF
Min Jung, MD, PhD, Seoul KOREA, REPUBLIC OF
Kwangho Chung, MD, Seoul KOREA, REPUBLIC OF
Hyun-Soo Moon, MD, PhD, Seoul KOREA, REPUBLIC OF
Sung-Hwan Kim, MD, PhD, Seoul KOREA, REPUBLIC OF
Severance Hospital, Seoul, Seoul, KOREA, REPUBLIC OF
FDA Status Cleared
Summary
The optimal orientations of the ALL tibial tunnel to avoid collision with the ACL tibial tunnel and prevent saphenous nerve injury were axial 10°–coronal 30° and axial 20°–coronal 30° for surgical techniques requiring far-cortex drilling.
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Abstract
Background
Collision risks between femoral tunnels during combined anterior cruciate ligament (ACL) and anterolateral ligament (ALL) reconstruction have been reported. However, studies on collision risks between tunnels and optimal ALL tibial tunnel orientation are lacking.
Purpose
To analyze the optimal orientation of the ALL tibial tunnel to minimize collisions with the ACL tibial tunnel while preventing injury to the saphenous nerve in combined reconstruction
Study design: Descriptive Laboratory study; level of evidence IV.
Methods
Preoperative magnetic resonance imaging (MRI) and postoperative computed tomography (CT) images of patients who underwent primary ACL reconstruction were analyzed. Only patients with preoperative MRI scans including less than 1mm thickness thin-cut images were included for 3-dimensional (3D) reconstruction. Bony structures of the knee joint, including the proximal tibia with the actual ACL tibial tunnel, were reconstructed from the postoperative CT scans. The greater saphenous vein (GSV), which runs together with the saphenous vein, was reconstructed from the preoperative MRI data and subsequently transferred to the CT model, maintaining the appropriate positional relationship. Twelve different orientations of the ALL tunnel (10° intervals, ranging from 0° to 20° axially [anteriorly] and from 0° to 30° coronally [distally]) were simulated with the final 3D model to measure the distance between the ALL tunnel trajectory and other structures (ACL tibial tunnel, GSV) by each orientation.
Results
Among a total of 304 patients, thirty-five were included in this study. The minimum distance to the ACL tunnel increased with more distally oriented ALL tunnels and decreased with more anteriorly oriented ones. The minimum distance to GSV decreased with more distally oriented ALL tunnels and increased with more anteriorly oriented ones. Axial 10°–coronal 30° and axial 20°–coronal 30° were identified as optimal orientations for ALL tibial tunnels, considering both collisions with the ACL tunnel and the potential risk of injury to the saphenous nerve.
Conclusion
The optimal orientations of the ALL tibial tunnel to avoid collision with the ACL tibial tunnel and prevent saphenous nerve injury were axial 10°–coronal 30° and axial 20°–coronal 30° for surgical techniques requiring far-cortex drilling.
Key Terms: Anterior cruciate ligament reconstruction, Anterolateral ligament, Anterolateral ligament reconstruction, Tunnel collision, Saphenous nerve