Purpose The purpose of this study was to verify the eicacy of a novel technique for additional tying on the adjustable-loop device to prevent stress concentration on the graft loop end and gradual loop lengthening. Methods A total of 124 patients who underwent anterior cruciate ligament reconstruction using hamstring autografts from 2014 to 2017 were included in this retrospective study. After 1:1 propensity score matching, two groups were formed (group I: 50 patients without tying vs. group II: 50 patients with tying). Anterior laxity was evaluated using side-to-side diferences. Tunnel length, loop length, and graft-tunnel gap were measured using follow-up magnetic resonance imaging. The signal-to-noise ratio was calculated at the loop end, loop inner side, tunnel entrance, and graft mid-substance. The clinical outcomes were assessed using the International Knee Documentation Committee score, Lysholm score, pivot shift test, and Lachman test.
ResultsThe average follow-up period was 63.2 ± 4.8 and 53.8 ± 11.9 months in groups I and II, respectively. Anterior laxity showed that side-to-side diferences improved signiicantly 6 months postoperatively in both the groups. Although the anterior laxity improved in group II (2.9 ± 1.0 to 1.6 ± 0.8, p < 0.001), it deteriorated in group I (2.5 ± 1.5 to 3.3 ± 1.3 mm, p < 0.001) at the inal follow-up. The graft-tunnel gap was signiicantly larger in group I (p < 0.001). The signal-to-noise ratios of the loop end and loop inner side were signiicantly higher in group I (p < 0.001 and p = 0.020, respectively). The clinical outcomes at the inal follow-up were not signiicantly diferent between the groups. Conclusion The additional tying on the adjustable-loop device was not superior to the control group in clinical stability examination or outcome. However, it was efective in anterior laxity measured by stress radiographs, preventing stress on the adjustable-loop device, and gradual graft loop lengthening. Level of evidence Level III.