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 degrees and 120 degrees of flexion. Three femoral tunnels were marked with guidewires and measured radiographically in 8 fresh-frozen cadaveric knees using both techniques. Results were analyzed. The mean graft/femoral tunnel angle was 34.4 degrees +/- 14.4 degrees for the outside-in technique, 52.3 degrees +/- 14.1 degrees for the inside-out technique at 120 degrees of flexion, and 74.4 degrees +/- 11 degrees for the inside-out technique at 90 degrees of flexion. The angle was smaller for the outside-in technique versus the inside-out technique at both 120 degrees (P = .019) and 90 degrees 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 degrees of flexion produces smaller angles than does 90 degrees of flexion. The outside-in technique results in lower angles and perhaps lower graft failure rates. However, additional clinical studies are needed.