The 45° and 60° of sagittal femoral tunnel placement in anterior cruciate ligament reconstruction provide similar knee stability.

Abstract

The aim of the present study was to compare 45° and 60° of sagittal femoral tunnel angles in terms of anterior tibial translation (ATT), valgus angle and graft in situ force following anterior cruciate ligament reconstruction (ACLR). Ten porcine knees were subjected to the following loading conditions: (1) 89 N anterior tibial load at 35° (full extension), 60° and 90° of knee flexion and (2) 5 N m valgus tibial moment at 35° and 45° of knee flexion. ATT and graft in situ force of the intact anterior cruciate ligament (ACL) and ACLR were collected using a robotic universal force/moment sensor (UFS) testing system for (1) ACL intact, (2) ACL-deficient (ACLD) and (3) two different ACLR using different sagittal femoral tunnel angles (coronal 45°/sagittal 45° and coronal 45°/sagittal 60°). During the anterior tibial load, the femoral tunnel angle of ACLR knees at coronal 45°/sagittal 45° and 60° had significantly higher ATT than that of the ACL-intact knees at 60° of knee flexion (p < 0.05). The femoral tunnel angle of ACLR knees at coronal 45°/sagittal 60° had significantly lower graft in situ force than that of the ACL-intact knees at 60° and 90° of knee flexion (p < 0.05). During the valgus tibial moment, the femoral tunnel angle of ACLR knees at coronal 45°/sagittal 45° and 60° had significantly lower graft in situ force than that of the ACL-intact knees at all knee flexions (p < 0.05). The femoral tunnel angle of ACLR knees at coronal 45°/sagittal 45° provided similar ATT, valgus angle and graft in situ force to that of ACLR knees at coronal 45°/sagittal 60°. Therefore, both femoral tunnel angles could be used in ACLR, as the sagittal femoral tunnel angle does not appear to be relevant in post-operative knee stability. Not applicable.