Contralateral ACL Rupture as an Indicator of Intrinsic Risk for Graft Failure After ACL Reconstruction: A Cohort Study of 7718 Patients From the SANTI Study Group.

Abstract

Graft failure after anterior cruciate ligament (ACL) reconstruction (ACLR) may be influenced by both extrinsic exposure and intrinsic patient susceptibility. A contralateral ACL rupture could reflect an inherent predisposition to ligament injury. To determine whether a history of bilateral native ACL ruptures increases the risk of graft failure after primary ACLR. Cohort study; Level of evidence, 2. A total of 7718 consecutive patients who underwent primary ACLR by a single surgeon (2003-2022) were included. Graft failure, defined as a clinically and magnetic resonance imaging-confirmed rupture, was compared between patients with bilateral versus unilateral native ACL ruptures. Multivariable logistic regression identified independent predictors, including age, sex, Tegner score, sport type, and a history of bilateral rupture. The cohort included 6327 patients with isolated native ACL rupture and 1391 patients with bilateral native ACL rupture. The overall graft failure rate was 6% (461-7718), with a mean follow-up of 135.9 months. Patients with bilateral ACL ruptures had a higher failure rate (9.3%) than those with unilateral injuries (5.2%) (<i>P</i> < .0001). Independent predictors included younger age (odds ratio [OR], 0.92 [95% CI, 0.90-0.93]; <i>P</i> < .0001), male sex (OR, 1.46 [95% CI, 1.10-1.96]; <i>P</i> = .0089), higher Tegner score (OR, 1.09 [95% CI, 1-1.19]; <i>P</i> = .043), and bilateral rupture (OR, 1.34 [95% CI, 1.03-1.73]; <i>P</i> = .028). Bilateral native ACL rupture independently increases the risk of graft failure after ACLR. This finding supports its use as a marker of intrinsic vulnerability that may warrant targeted preventive or surgical strategies.