The Graft/Femoral Tunnel Angles in Posterior Cruciate Ligament Reconstruction – A Comparison of 3 Techniques for Femoral Tunnel Placement

ABSTRACT

This study compared the graft/femoral tunnel angle produced with the outside-in technique with the inside-out technique at 90° and 120° of flexion. Three femoral tunnels were marked with guide-wires and measured radiographically in 8 fresh-frozen cadaveric knees using both techniques. Results were analyzed. The mean graft/femoral tunnel angle was 34.4°±14.4° for the outside-in technique, 52.3°±14.1° for the inside-out technique at 120° of flexion, and 74.4°±11° for the inside-out technique at 90° of flexion. The angle was smaller for the outside-in technique versus the inside-out technique at both 120° (P = .019) and 90° of knee flexion (P < .001).

The outside-in technique for femoral tunnel placement produces the lowest graft/femoral tunnel angle in cadavers. With the inside-out technique, 120° of flexion produces smaller angles than does 90° of flexion. The outside-in technique results in lower angles and perhaps lower graft failure rates. However, additional clinical studies are needed.