CT assessment of femoral tunnel placement after partial ACL reconstruction

Abstract

Introduction: When one of the anterior cruciate ligament (ACL) bundles is torn, it seems appropriate to preserve the remaining bundle to improve the vascularization and proprioception of the graft, and to reproduce the attachment sites of the torn bundle. After ACL reconstruction, the functional result is worse when the tunnels are positioned further away from the native ACL's isometric attachment points. The goal of this study was to use CT 3D reconstructions to analyse the position of the femoral tunnel following partial ACL reconstruction and to compare it to complete ACL reconstruction cases. We hypothesized that the femoral tunnel positioning was optimal during partial ACL reconstruction.

Methods: In this prospective single-centre study, 16 patients who underwent isolated anteromedial bundle reconstruction were evaluated during the immediate postoperative period using 3D reconstruction of CT images. During this same period, 180 patients who underwent complete ACL reconstruction in the same surgery unit served as a control group.

Results: In the partial ACL reconstruction group, 6 tunnels (37.5%) were in the optimal position and 10 tunnels (62.5%) were not. In the complete ACL reconstruction group, 124 femoral (68.9%) were in the optimal position and 56 (31.1%) were not (P<0.05).

Discussion: Femoral tunnel positioning is not always optimal in patients who undergo partial ACL reconstruction. Three-dimensional CT reconstruction is a good tool to help surgeons detect and learn from their errors.

Level of evidence: III (case-control study).

Keywords: 3D CT scan; Anterior cruciate ligament; Femoral tunnel; Partial ACL reconstruction; Partial tear.