Ten-year risk of graft re-rupture and contralateral anterior cruciate ligament injury after primary anterior cruciate ligament reconstruction: A systematic review and meta-analysis

IMPORTANCE: The second anterior cruciate ligament (ACL) injury after ACL reconstruction is a well-known complication. Several studies have suggested that the risk of contralateral ACL injury is comparable to that of graft re-rupture. However, this comparison is not well established in previous reviews for studies with minimum five-year follow-up and mean ten-year outcomes. OBJECTIVE: This systematic review and meta-analysis aimed to evaluate the ten-year risk of graft re-rupture and contralateral ACL injury after primary ACL reconstruction and to assess the influence of graft type, return-to-sport, and other factors on second ACL injuries. EVIDENCE REVIEW: A systematic search was conducted across the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and Cochrane from 2000 to 2025. The literature search strategy included the following keywords: "anterior cruciate ligament reconstruction," "ACL reconstruction," "graft rupture," "graft failure," "contralateral anterior cruciate ligament injury," and "contralateral ACL injury." All studies that compare the risk of re-rupture and contralateral ACL injuries after ACL reconstruction and with a follow-up of at least five years after ACL reconstruction were included. Exclusion criteria included case reports, reviews, studies using allografts or artificial ligaments, and multi-ligament injuries. FINDINGS: A total of 18 studies were included in this meta-analysis with 5,735 participants. The pooled rates of graft rupture and contralateral injuries were 11 % and 12 %, respectively, with no statistically significant difference (p = 0.421). The ipsilateral graft-rupture rate was higher in patients with hamstring tendon (HT) autografts compared with bone-patellar tendon-bone (BPTB) autografts, at 13.0 % and 7.74 %, respectively (odds ratio [OR] = 1.75, 95 % confidence interval [CI]: 1.33-2.31; p = 0.004). Younger age (