Effects of flexible reamer on the femoral tunnel characteristics in anterior cruciate ligament reconstruction

To compare the femoral tunnel characteristics using a rigid versus flexible reamer during anterior cruciate ligament reconstruction. It was hypothesized that the employment of a flexible reamer along with femoral tunnel would exhibit longer tunnel length and more acute femoral graft tunnel angle compared to the case of a rigid reamer. The study population included 28 patients who underwent anatomical single-bundle anterior cruciate ligament reconstruction using transportal technique and were able to take postoperative computed tomography (CT) evaluation. Of these, the femoral tunnel of 14 cases was drilled with a flexible reamer (group I) and in another 14 cases drill was performed with a conventional rigid reamer (group II). The femoral tunnel in group I was made at 90 degrees of knee flexion. In group II, the femoral tunnel was created at 120 degrees of knee flexion. The parameters of the femoral tunnels were compared in terms of the femoral tunnel length and femoral graft tunnel angle. Special software was used to create and manipulate (3-D) 3-dimensional knee models. The difference in the mean femoral tunnel locations expressed in percentage distance between the 2 groups was not significantly different. The mean femoral tunnel length of group I was significantly longer than that of group II, (P = .03, 36.7 +/- 2.9 vs 32.9 +/- 9.0 mm). The angle formed by the femoral tunnel and the graft in group I was significantly smaller than in group II (P = .01, 109.8 degrees +/- 9.4 degrees vs 118.1 degrees +/- 7.2 degrees). Our data suggest that the flexible reamer can provide sufficient tunnel length for the suspensory fixation with a fixed loop. Whereas, the femoral graft-tunnel angle through flexible reaming at 90 degrees of knee flexion was more acute compared to rigid reaming at 120 degrees of knee flexion. Study Design: level of evidence III

Automated summary

The study compared the femoral tunnel characteristics during ACL reconstruction using rigid and flexible reamers, finding that the flexible reamer resulted in longer tunnel length and a more acute femoral graft-tunnel angle.