Abstract:Objective To analyze the predictive value of preoperative magnetic resonance imaging (MRI) indexes in patients with full thickness rotator cuff tear (FTRCT) undergoing arthroscopic rotator cuff repair (ARCR).Methods Clinical data of 451 patients with FTRCT undergoing ARCR from January 2020 to December 2023 were retrospectively included as the study objects. All patients were followed up for 1 year after surgery. Patients were divided into the shoulder joint function improvement group (n = 415) and the shoulder joint function non-improvement group (n = 36) according to scores of disabilities of the arm shoulder and hand (DASH). The preoperative MRI indicators and clinical indicators of the two groups were compared, and the risk factors of the outcome after ARCR in patients with FTRCT were analyzed by multivariate Logistic regression, and the receiver operating characteristic curve (ROC curve) was drawn. The predictive value of preoperative MRI indexes alone and in combination in patients with FTRCT undergoing ARCR was analyzed.Results 451 patients with FTRCT after ARCR were followed up for 1 year. The incidence of shoulder joint function non-improvement was 7.98%. Compared with the shoulder joint function improvement group, the shoulder joint function non-improvement group had longer preoperative tendon tear width and tendon retraction distance, higher degree of tendon degeneration, and shorter acromial humeral space (P < 0.05). Acromial humeral space ≤7.15 mm (OR^ = 2.208, 95%CI: 1.255 ~ 3.883), tendon degeneration degree 2-3 (OR^ = 1.817, 95%CI: 1.066 ~ 3.096), tendon tear width > 2.16 cm (OR^ = 2.246, 95%CI: 1.242 ~ 4.059) and tendon retraction distance > 2.10 cm (OR^ = 2.186, 95%CI: 1.311 ~ 3.646) were risk factors for non-improvement of the shoulder joint in patients with FTRCT after ARCR (P < 0.05). Positive as shoulder joint function nonimprovement was included and negative as shoulder joint function improvement, ROC was drawn, and the predictive value of preoperative MRI indexes detection alone and combined in patients with FTRCT after ARCR was analyzed. The area under the curve (AUC) was 0.903, the sensitivity was 86.11%, and the specificity was 87.47%.Conclusion Patients with FTRCT who underwent ARCR surgery have better outcomes. Tendon tear width > 2.16 cm, tendon retraction distance > 2.10 cm, tendon degeneration degree of grade 2 to 3, acromial humeral space ≤ 7.15 mm are risk factors for poor outcomes, and the combined detection of preoperative MRI indexes has high predictive value.