Abstract: Objective To explore the correlation between lumbar spine bone mineral density and the occurrence of large rotator cuff tears. Methods A total of 109 patients with arthroscopic shoulder surgery in the Department of Arthroplasty Surgery in Kunshan Hospital of Traditional Chinese Medicine from January 2018 to October 2023 were selected and divided into large rotator cuff tear group (n=27) and small rotator cuff tear group (n=82) according to the severity of the rotator cuff tears. General materials of patients were collected, and multivariate Logistic regression analysis was used to investigate the correlation between lumbar spine bone mineral density and the occurrence of large rotator cuff tears. Results The large rotator cuff tear group had significant higher age and higher proportion of patients with a history of trauma compared to the small rotator cuff tear group (P<0.05); additionally, the levels of total cholesterol, albumin, serum magnesium, total hip bone mineral density, and lumbar spine bone mineral density were significantly lower in the large rotator cuff tear group (P<0.05). The results of multivariate Logistic regression analysis indicated that lumbar spine bone mineral density was associated with the occurrence of large rotator cuff tears. The prevalence of large rotator cuff tears across the four quartile intervals of lumbar spine bone mineral density named as Q1 (<0.870 g/cm²), Q2 (0.870～<0.991 g/cm²), Q3 (0.991～1.137 g/cm²), and Q4 (>1.137 g/cm²) were 48.15%, 29.63%, 18.52% and 3.70% respectively, showing a gradual decreasing trend with significant differences (P<0.05). Conclusion There is a correlation between lumbar spine bone mineral density and large rotator cuff tears. The lower the bone density of the lumbar spine is, the higher the risk of large rotator cuff tears will be.