The use of a mono-fluted reamer results in decreased enlargement of the tibial tunnel when using a transtibial ACL reconstruction technique

Purpose: To evaluate whether femoral tunnel preparation using a mono-fluted reamer rather than an acorn reamer would result in less tibial tunnel deformation when using a transtibial technique for anterior cruciate ligament reconstruction. Methods: Tibial and femoral tunnel preparation was performed in four matched pairs of cadaveric knees. The tibial tunnel was drilled using a standard acorn reamer. The femoral tunnel was prepared using a transtibial technique with a mono-fluted reamer, and then, the same femoral tunnel was re-reamed using an acorn reamer. The anterior-posterior (AP) and medial-lateral (ML) dimensions of the tibial tunnel were recorded after each reamer. We then compared the measurements following the use of each reamer using a paired two-sample t test. Results: There was a significantly larger degree of tibial tunnel deformation following femoral tunnel preparation with the acorn reamer when compared with the mono-fluted reamer. The initial tibial tunnel measured 10.5 and 10.1 mm in the AP and ML dimensions, respectively. The resultant AP diameter of the tibial tunnel after femoral reaming was 16.7 mm (p < 0.001) for the acorn reamer compared with 11.6 mm (p < 0.001) for the mono-fluted reamer. The ML diameters were 11.3 mm (p = 0.003) versus 10.2 mm (p = 0.07) for the acorn and mono-fluted reamer, respectively. Conclusion: The use of a mono-fluted reamer for femoral tunnel preparation results in less tibial tunnel deformation during transtibial reaming.