Purpose: This study aimed to prospectively compare the femoral tunnel enlargement at the aperture as well as inside the tunnel after anatomic anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone (BTB) graft to that with hamstring tendon (HST) graft.
Methods: This study included 24 patients with unilateral ACL rupture. Twelve patients underwent anatomic rectangular tunnel (ART) ACL reconstruction with BTB graft and the remaining 12 underwent anatomic triple-bundle (ATB) ACL reconstruction with HST graft. Three-dimensional computer models of femur and bone tunnels were reconstructed from computed tomography images obtained at 3 weeks and 1 year postoperatively. The femoral tunnel enlargement from 3 weeks to 1 year was evaluated by comparing the cross-sectional area (CSA), and compared between the two groups.
Results: The CSA in the ART group at 1 year decreased at the aperture as well as inside the tunnel comparing that at 3 weeks. The CSAs of both tunnels in the ATB group at 1 year significantly increased at the aperture in comparison to those at 3 weeks, and gradually decreased toward the inside of the tunnel. The enlargement rate at the aperture in the ART group was -12.9%, which was significantly smaller than that of anteromedial graft (27.9%; P = 0.006) and posterolateral graft (31.3%; P = 0.003) in the ATB group. The tunnel enlargement rate at 5 mm from the aperture in the ART group was also significantly smaller than that in the ATB group. At 10 mm from the aperture, there was no significant difference between the tunnel enlargement rate in the ART group and that of anteromedial tunnel.
Conclusions: The tunnel enlargement rate around the aperture was significantly smaller after the ART procedure than that after the ATB procedure. Thus, BTB graft might be preferable as a graft material to HST graft in the femoral tunnel enlargement.
Copyright © 2018 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.