Duong JKH, , et al. - In this study, the association between preoperative and intra-operative factors and re-tear rate following rotator cuff repair was ascertained, and to formulate a predictive model based upon this relationship, including any interaction effects between tear size, patient age, and surgical experience in contributing to re-tear rate. Researchers conducted a post-hoc analysis on prospectively collected data from 1,962 consecutive patients who had undergone a primary arthroscopic single-row rotator cuff repair by the senior author from 2007 to 2018, and postoperatively returned for 6-month follow-up ultrasonography. The study found that anteroposterior tear length was the most important independent predictor of re-tear or non-healing. The Case number, patient age at surgery and hospital type were other predictive factors. According to the results, the predictive impact of anteroposterior tear length and patient age and case number in contributing to re-tear was additive. The regression equation may be applied to estimate patient rotator cuff re-tear risk at 6 months post-repair.