Background: As anterior cruciate ligament (ACL) reconstruction failures rise, there is increasing recognition of the graft bending angle (GBA) as a potential risk factor for graft failure. Purpose: This study aims to investigate the association between steeper GBA and the need for a revision ACL reconstruction. In addition, this study proposes a standardized protocol for GBA measurement using more readily accessible radiograph imaging. Methods: A retrospective analysis of ACL reconstruction revisions performed at a single institution from January 1, 2017, to July 30, 2024, was conducted. Patients were included if they had available radiographic imaging between the primary ACL reconstruction and revision. Measurements of coronal GBA, femoral tunnel incline, and tibial tunnel incline were recorded from radiographs before ACL revision. Surgical data, including graft types and femoral tunnel drilling technique, were collected. Revision patients were compared with a matched control group who did not require revision. Results: A total of 81 patients who underwent ACL revision surgery were included. The average coronal GBA was 155.4° ± 12.30°, femoral tunnel incline was 47.9° ± 14.14°, and tibial tunnel incline was 67.2° ± 7.60. Coronal GBA varied by drilling technique, with notable differences between retroreaming (RR) (147.71° ± 11.43°) and transtibial (164.96 ± 11.82°; P = 0.019). A notable difference between the coronal GBA of cases (153.43° ± 12.52°) and controls (158.35° ± 8.50°) was found ( P = 0.030). Conclusion: In this retrospective analysis, we found that RR femoral tunnel results in the most acute GBA in the coronal plane and that GBAs were more acute in cases of failed ACL reconstructions, by 5°, compared with matched controls. Our findings underscore the utility of two-dimensional radiographic imaging for measuring GBA in patients undergoing ACL revision surgery and consideration for limiting the obliquity of the femoral tunnel during primary ACL reconstruction.
Weiss et al. (Sun,) studied this question.