Anteromedial and posterolateral graft kinematics of a double-bundle ACL reconstruction: a 3D computer simulation

BackgroundThe posterolateral graft has been reported to fail more frequently than the anteromedial graft in double-bundle ACL reconstructions. This study investigated the graft kinematics using a 3D modelling technique. MethodsTwenty subjects performed a stair-ascending activity under dual fluoroscopy surveillance. A double-bundle ACL reconstruction was simulated on those healthy knees using an anteromedial portal technique. The graft-tunnel interaction was described using the graft-tunnel angle and the range of the graft-tunnel edge contact (GTEC). ResultsThe femoral graft-tunnel angle of the anteromedial/posterolateral graft was 97.6 7.5/100.7 +/- 7.7 degrees and the tibial graft-tunnel angle was 158.8 +/- 6.5/146.5 +/- 8.9 degrees at knee extension. The femoral GTEC ranges were 23.2 +/- 5.3-28.1 +/- 7.6 degrees for both grafts and the tibial GTEC ranges were 27.3 +/- 2.2-34.5 +/- 2.1 degrees during stair-ascending. ConclusionThe femoral graft-tunnel angle was larger than on the tibial side and the GTEC angles influenced the PL graft more, implying that grafts may experience a less optimal biomechanical environment at the femoral tunnels. Copyright (c) 2015 John Wiley & Sons, Ltd.