Causes of anterior cruciate ligament reconstruction failure: A meta-analysis

Anterior cruciate ligament (ACL) injury is one of the most common knee injuries among athletes and during sports activities for which ligament reconstruction is the optimal therapeutic procedure. Functional instability of the knee because of ACL injury is prone to relapse. Relapse is commonly reported following surgery due to various reasons. Knowing the possible causes are major key in the management of patients with an ACL tear after reconstruction. This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. PubMed, Cochrane library, and Google Scholar were searched for eligible articles from January 1, 2010, to December 31, 2020. The articles were selected on inclusion and exclusion criteria mentioned in the study protocol. Following the screening of all the articles, the short-listed articles were subjected to full-text review by two independent reviewers. The overall search process gave us 1571 articles in total, from which 13 were selected for meta-analysis. A total of 891 patients were included in the 13 studies evaluated with respect to the factors responsible for failure of the primary ACL reconstructive procedure. Tunnel placement error and traumatic reinjury were the most reported associated factors responsible for primary ACL reconstruction failure. However, the overall summary estimate for the two major etiologies was not significant. The P-value for overall effect was 0.76, along with a Z score of 0.30 and an I2 test value of 91%, indicating high study variability. The odd’s ratio was calculated using the Mantel-Haenszel random effects model for ACL reconstruction failure, which was 0.88. Understanding the cause of primary ACL failure and developing strategies to minimize or avoid it completely will help in reducing the incidence of ACL reconstructive failure and improve patient outcomes.