Kunihiko Hiramatsu1, Tatsuo Mae2, Yuta Tachibana3, Shigeto Nakagawa3, Konsei Shino3. 1. Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan. k-hiramatsu@umin.ac.jp. 2. Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan. 3. Sports Orthopaedic Center, Yukioka Hospital, 2-2-3 Ukita, Kita-ku, Osaka, Osaka, 530-0021, Japan.
Abstract
PURPOSE: The purpose of this study was to compare the femoral tunnel length, the femoral graft bending angle at the femoral tunnel aperture, and the contact area between the femoral tunnel wall and an interference screw used for fixation in anatomic rectangular tunnel anterior cruciate ligament (ACL) reconstruction (ART ACLR). METHODS: The study included 149 patients with primary ACL injury who underwent ART ACLR. Preoperatively, flexion angle of the index knee was checked under general anaesthesia. Those of less than 130° of passive flexion were assigned to the outside-in (OI) technique (78 patients), while the others to the trans-portal inside-out (TP) technique (71 patients). The patients underwent computed tomography with multiplanar reconstruction at 3-5 weeks post-operatively. Femoral tunnel length, graft bending angle, and contact ratio between the IFS and femoral tunnel were assessed. P < 0.05 was considered statistically significant. RESULTS: The femoral tunnel length in the OI technique was significantly longer than that in the TP technique (P < 0.001). The femoral graft bending angle in the OI technique was significantly more acute than that in the TP technique (P < 0.001). The contact ratio in the OI technique was significantly larger than that in the TP technique at every point in the femoral tunnel (P < 0.001). CONCLUSIONS: The OI technique resulted in a more acute femoral graft bending angle, longer mean femoral tunnel length, and larger contact ratio than the TP technique after ART ACLR. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.
PURPOSE: The purpose of this study was to compare the femoral tunnel length, the femoral graft bending angle at the femoral tunnel aperture, and the contact area between the femoral tunnel wall and an interference screw used for fixation in anatomic rectangular tunnel anterior cruciate ligament (ACL) reconstruction (ART ACLR). METHODS: The study included 149 patients with primary ACL injury who underwent ART ACLR. Preoperatively, flexion angle of the index knee was checked under general anaesthesia. Those of less than 130° of passive flexion were assigned to the outside-in (OI) technique (78 patients), while the others to the trans-portal inside-out (TP) technique (71 patients). The patients underwent computed tomography with multiplanar reconstruction at 3-5 weeks post-operatively. Femoral tunnel length, graft bending angle, and contact ratio between the IFS and femoral tunnel were assessed. P < 0.05 was considered statistically significant. RESULTS: The femoral tunnel length in the OI technique was significantly longer than that in the TP technique (P < 0.001). The femoral graft bending angle in the OI technique was significantly more acute than that in the TP technique (P < 0.001). The contact ratio in the OI technique was significantly larger than that in the TP technique at every point in the femoral tunnel (P < 0.001). CONCLUSIONS: The OI technique resulted in a more acute femoral graft bending angle, longer mean femoral tunnel length, and larger contact ratio than the TP technique after ART ACLR. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.