Background: To identify and quantify the factors associated with the reparability of rotator cuff tears (RCTs). Methods: PubMed, Scopus, and Web of Science databases were searched for clinical studies published in English focusing on RCT reparability by using the keywords "rotator cuff tear"and "reparability". A meta-analysis was conducted if >= 3 studies examined the same factor and provided enough data to assess RCT reparability. Quality assessment was completed using the quality assessment of diagnostic accuracy studies tool. Results: Eighteen studies (2700 patients) were enrolled and 26 factors were included in the meta-analysis. The dichotomous variables associated with irreparability were Patte stage 3 (odds ratio (OR): 8.0, 95% confidence interval [CI]: 4.3-14.9), massive tear vs. large tear (OR: 3.1, 95% CI: 1.3-7.2), Goutallier stage for each tendon, and tangent sign (OR: 11.1, 95% CI: 4.3-28.4). The continuous variables associated with irreparability were age (mean difference (MD): 3.25, 95% CI: 1.4-5.1), mediolateral tear size (MD: 12.3, 95% CI: 5.818.9), anteroposterior tear size (MD: 10.4, 95% CI: 5.2-15.6), acromiohumeral distance on X-ray (MD: 2.3, 95% CI: 3.0 to 1.6) and magnetic resonance imaging (MD: 1.8, 95% CI: 2.8 to 0.9), and inferior glenohumeral distance on magnetic resonance imaging (MD: 2.2, 95% CI: 1.4-3.0). Conclusion: This study revealed that older age, larger tear size, severe fatty infiltration, muscle atrophy, and advanced superior migration of the humeral head were strongly associated with irreparable RCTs. Conversely, clinical symptoms provided limited information for predicting reparability. Additionally, the tangent sign emerged as a powerful and simple tool for individual prediction, and several quantitative scoring systems also proved useful.