Tunnel collision during simultaneous anterior cruciate ligament and posterolateral corner reconstruction.

PURPOSE

To verify the safest angle to drill femoral tunnels in simultaneous anterior cruciate ligament (ACL) and posterolateral corner (PLC) reconstructions to minimize the risk of tunnel collision and to examine the relationship between lateral femoral condyle (LFC) width and tunnel collision occurrence.

METHODS

Ten fresh-frozen cadaveric knees were used. In each knee, anatomical single-bundle ACL femoral tunnels were arthroscopically drilled at 120 and 140 degrees of flexion, and tunnels for popliteus tendon (PLT) and fibular collateral ligament (FCL) were drilled at 20° axial/20° coronal angulations and 10° axial/30° coronal angulations. Three-dimensional computed tomography exams of the knees were performed. The presence of tunnel collision was evaluated, and the minimal distance between tunnels and the LFC width was measured.

RESULTS

Risk of tunnel collision was significantly increased if FCL and PLT tunnels were drilled at 10° axial/30° coronal angulation (P < 0.05). Tunnel collision was noted in only one knee when FCL and PLT tunnels were drilled at 20° axial/20° coronal angulations. Knees with smaller LFC width had significantly higher risk for tunnel collision (P < 0.05).

CONCLUSION

Drilling PLT and FCL femoral tunnels at 20° axial/20° coronal angulation is a safe positioning for simultaneous ACL and PLC reconstructions. However, in smaller knees, the risk for tunnel collision could be greater. Surgeons should consider the possibility of tunnel collision when performing simultaneous ACL and PLC anatomical reconstruction, especially in knees with a small LFC width where the risk for tunnel collision could be greater.