# Comparison of the accuracy of two guiding devices for femoral tunnel position in anterior cruciate ligament reconstruction surgery: A radiographic study

## TL;DR

This study compared two tools for placing a femoral tunnel during ACL surgery, finding that the modified tool placed the tunnel closer to the ideal anatomical position.

## Contribution

The modified locator improves femoral tunnel placement accuracy near the posterior wall in ACL reconstruction.

## Key findings

- Group B's tunnel centers were closer to the posterior region of the femoral footprint.
- The modified locator significantly reduced the distance from the tunnel's posterior edge to the posterior wall.
- Both groups had similar posterior wall rupture rates, but Group B's tunnels were more anatomically accurate.

## Abstract

This study evaluated the comparative efficacy of two guiding devices in positioning the femoral tunnel in the ‘Isometric, Direct insertion, Eccentrically located, Anatomical, Low tension’ (I.D.E.A.L.) zone during anterior cruciate ligament reconstruction.

A retrospective analysis was conducted on 64 patients. Group A (32 cases) used traditional tools, while Group B (32 cases) used the modified locator. Postoperative three‐dimensional computed tomography reconstructions of the femoral condyle were performed, and tunnel position (using the quadrant method) and the distance from the tunnel's posterior edge to the lateral condyle posterior wall were measured. Statistical analysis was performed to compare the differences between the two groups.

The mean femoral tunnel centre positions were 30.3% ± 4.5% (deep–shallow) and 25.5% ± 9.6% (high–low) in Group A, and 25.9% ± 3.9% (deep–shallow) and 26.6% ± 5.8% (high–low) in Group B. The ideal I.D.E.A.L. tunnel centre was defined at (28.4, 22.2). No significant difference in dispersion was observed between the two groups. But the tunnel centre in Group B is more concentrated near the posterior region of the femoral footprint. The distance from the posterior tunnel edge to the posterior wall was 3.5 ± 1.7 mm in Group A and 2.2 ± 1.0 mm in Group B, showing a significant difference. Each group had 1 case of the posterior wall rupture; the rupture rate did not differ significantly between the groups.

The modified locator facilitates femoral tunnel placement closer to the posterior wall, which promotes the biomechanical conditions required for optimal graft isometry and low tension.

Level IV and V, retrospective study.