Effect of tunnel position for anatomic single-bundle ACL reconstruction on knee biomechanics in a porcine model

Attention has been focused on the importance of anatomical tunnel placement in anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to compare the effect of different tunnel positions for single-bundle (SB) ACL reconstruction on knee kinematics. Ten porcine knees were used for the following reconstruction techniques: three different anatomic SB [AM–AM (antero-medial), PL–PL (postero-lateral), and MID–MID] ( n = 5 for each group), conventional SB (PL–high AM) ( n = 5), and anatomic double-bundle (DB) ( n = 5). Using a robotic/universal force–moment sensor testing system, an 89 N anterior load (simulated KT1000 test) at 30, 60, and 90° of knee flexion and a combined internal rotation (4 N m) and valgus (7 N m) moment (simulated pivot-shift test) at 30 and 60° were applied. Anterior tibial translation (ATT) (mm) and in situ forces (N) of reconstructed grafts were calculated. During simulated KT1000 test at 60° of knee flexion, the PL–PL had significantly lower in situ force than the intact ACL ( P