Tunnel Overlap Occurs 25% of the Time With Simultaneous Anterior Cruciate Ligament Reconstruction and Lateral Meniscal Root Repair.

Purpose: To assess the risk of socket-tunnel overlap for posterior medial or lateral meniscal root repair combined with anterior cruciate ligament reconstruction (ACLR) using artificial tibias and computed tomography scans for 3-dimensional modeling.

Methods: Artificial tibias (n = 27; n = 3/subgroup) were allocated to groups based on inclination of socket-tunnels (55°, 60°, 65°) created for posterior root of the medial meniscus (MMPR) and lateral meniscus posterior root (LMPR) repair, and ACLR. Three standardized socket-tunnels were created: one for the ACL and one for each posterior meniscal root insertion. Computed tomography scans were performed and sequentially processed using computer software to produce 3-dimensional models for assessment of socket-tunnel overlap. Statistical analysis was performed with Kruskal-Wallis and Mann-Whitney tests. Significance was set at < .05.

Results: The present study found no significant risk of tunnel overlap when drilling for combined ACLR and MMPR repair, whereas 7 cases of tunnel overlap occurred between ACL tunnels and LMPR (25.9% of cases). No subgroup or specific pattern of angulation consistently presented significantly safer distances than other subgroups for all distances measured.

Conclusions: This study demonstrated 25.9% rate of overlap for combined LMPR repair and ACLR, compared with 0% for MMPR repair with ACLR. Lower ACL drilling angle (55 or 60°) combined with greater lateral meniscus drilling angle (65°) produced no socket-tunnel overlap.

Clinical Relevance: Socket-tunnel overlap during meniscal root repair combined with ACLR may compromise graft integrity and lead to impaired fixation and treatment failure of either the ACL, the meniscus, or both. Despite this, risk for socket-tunnel overlap has not been well characterized.