ACL graft and contralateral ACL tear risk within ten years following reconstruction a systematic review

Background: Anterior cruciate ligament (ACL) graft tear and contralateral ACL injury have devastating effects on patient outcomes following ACL reconstruction. Long-term results after ACL reconstruction are being reported with greater frequency, allowing a detailed analysis of the longterm risk of failure. Methods:Asystematic reviewof prospective studies that recorded the risk of ACL graft rupture and contralateral ACL injury following primary ACL reconstruction was performed. All studies included intra-articular ACL reconstruction with modern techniques and patellar tendon or hamstring autograft with a minimum follow-up of ten years. Results: Nine studies met the inclusion and exclusion criteria. The overall ACL graft rupture risk was 7.9% (211 ruptures in 2682 reconstructions) and ranged from 3.2% to 11.1% in the individual studies. The overall risk of ACL injury in the contralateral limb was 12.5% (335 injuries in 2682 reconstructions) and ranged from 0.6% to 22.7% in the individual studies. Among the seven homogeneous studies that were pooled, the overall risk of a contralateral ACL tearwas 1.63 (95%confidence interval [CI]: 1.30 to 2.04) times that of a graft tear during the follow-up period. Conclusions: At a minimum follow-up time of ten years, the risk of contralateral ACL tear significantly exceeds the risk of ACL graft rupture. Further work is necessary to understand and potentially reduce this risk of graft and contralateral ACL tears. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.