A simple independent high-strength suture augmentation significantly improves tendon biomechanical properties in anterior cruciate ligament reconstruction

The all-inside anterior cruciate ligament reconstruction (ACLR) technique heavily depends on continuous graft stability, making graft preparation critical. Graft augmentation techniques have been proposed to enhance stability in ACLR. This biomechanical study investigated whether an independent high-strength suture augmentation, applied parallel to the tendon graft, improves construct properties. Thirty-eight specimens were allocated to three groups: Suture ( n = 10; No. 2 non-absorbable braided polyethylene), Graft ( n = 13; bovine tendon), and Graft+Suture ( n = 15; combined construct). All specimens underwent uniaxial tensile testing, including a preconditioning phase from 0 to 350 N followed by a load-to-failure test at 50 mm/min to determine elongation (mm), ultimate failure load (UFL, in N), and construct stiffness (N/mm). Statistical analysis was performed using one-way ANOVA with Bonferroni post-hoc analysis. The Graft+Suture group exhibited significantly lower elongation (2.72 ± 0.51 mm) compared with both the Graft group (4.44 ± 1.59 mm; MD -1.71 mm, 95% CI -2.86 to -0.56; p = 0.002) and the Suture group (7.77 ± 1.37 mm; MD -5.05 mm, 95% CI -6.29 to -3.81; p < 0.001). UFL was higher in the Graft+Suture group (1327.83 ± 388.13 N) than in the Graft group (925.52 ± 337.06 N; MD 664.93 N, 95% CI 335.82 to 994.04; p < 0.001). Similarly, stiffness was greater in the Graft+Suture group (229.17 ± 25.105 N/mm) compared with the Graft group (163.880 ± 31.3 N/mm; p < 0.001). In this in vitro bovine model, independent high-strength suture augmentation significantly improved tendon graft biomechanical properties, producing higher UFL and stiffness, while reducing elongation. These findings suggest a potential strategy for graft reinforcement, though a more cautious interpretation is warranted pending in vivo and clinical validation. Not applicable.