Risk Factors for Ipsilateral Versus Contralateral Reinjury After ACL Reconstruction in Athletes: A Systematic Review and Meta-analysis

Han Gao; Haichen Hu; Dandan Sheng; Luyi Sun; Jun Chen; Tianwu Chen; Shiyi Chen

doi:10.1177/23259671231214298

Risk Factors for Ipsilateral Versus Contralateral Reinjury After ACL Reconstruction in Athletes: A Systematic Review and Meta-analysis

Orthop J Sports Med. 2023 Dec 21;11(12):23259671231214298. doi: 10.1177/23259671231214298. eCollection 2023 Dec.

Authors

Han Gao^{1

2}, Haichen Hu^{1

2}, Dandan Sheng^{1

2}, Luyi Sun¹, Jun Chen¹, Tianwu Chen¹, Shiyi Chen¹

Affiliations

¹ Department of Sports Medicine, Huashan Hospital, Fudan University, Shanghai, China.
² H.G., H.H., and D.S. contributed equally to this study.

Abstract

Background: Anterior cruciate ligament (ACL) reinjury after ACL reconstruction (ACLR) can occur on the ipsilateral or contralateral side. Limited evidence exists regarding the difference between the incidence of reinjury to either knee, which is important in developing interventions to prevent ACL reinjury.

Purpose: To compare the reinjury rate of the ACL on the ipsilateral side versus the contralateral side in athletes after ACLR and investigate the risk factors that may cause different reinjury rates between the sides.

Study design: Systematic review; Level of evidence, 4.

Methods: A systematic review was performed based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies that involved ACL reinjury in athletes after ACLR were reviewed. Considering several risk factors, including age and sex, a comparison of ACL reinjury incidence on the ipsilateral and contralateral sides was performed using a meta-analysis.

Results: Of the 17 selected studies, 3 were found to be at high risk of bias, and thus, 14 (n = 3424 participants) studies were included in the meta-analysis. In this athletic population, the contralateral ACL had a significantly higher rupture rate than the ipsilateral graft (risk ratio [RR], 1.41; P < .0001). Female athletes were found to have a greater risk of ACL reinjury on the contralateral versus the ipsilateral side (RR, 1.65; P = .0005), but different results were found in male athletes. (RR, 0.81; P = .21). There was no statistical difference in the incidence rate of ACL reinjury to either side in adolescent athletes (RR, 1.15; P = .28).

Conclusion: The contralateral ACL was more vulnerable to reinjury than the ipsilateral side in athletes after ACLR. Female athletes were more likely to reinjure their contralateral native ACL, while the same trend was not found in their male counterparts. The reinjury rate was comparable in both knees in adolescent athletes.

Keywords: anterior cruciate ligament reinjury; athlete; contralateral; ipsilateral.

Publication types

Review