Association between long head of the biceps tendon origin and rotator cuff tears: An Magnetic Resonance Imaging-based retrospective observational cohort study

The long head of the biceps tendon (LHBT) plays an important role in glenohumeral stability and frequently coexists with rotator cuff (RC) pathology. Although anatomical variations in the glenoid origin of the LHBT have been described, their relationship with RC tears has not been fully elucidated. This study aimed to investigate the association between LHBT origin variations and the presence of full-thickness RC tears. This retrospective single-center cross-sectional case-control design, epidemiology study included patients aged 45-70 years who underwent shoulder magnetic resonance imaging for the evaluation of chronic nontraumatic shoulder pain or suspected RC impingement syndrome between January and December 2024. LHBT origin was classified on routine magnetic resonance imaging sequences into 3 patterns: posterior supraglenoid tubercle, supraglenoid tubercle, and dual attachment. Full-thickness RC tears involving the supraspinatus and/or infraspinatus tendons were evaluated. Scapular morphologic parameters, including critical shoulder angle and glenoid version, as well as demographic variables and metabolic comorbidities, were recorded. Associations were analyzed using nonparametric tests and binary logistic regression. A total of 1,067 patients were included (mean age, 56.5 &#xb1; 7.4 years). The overall prevalence of full-thickness RC tears was 40.2%. RC tears were significantly less associated in patients with a posterior LHBT origin compared with supraglenoid tubercle and dual attachment patterns (P < .001). Multivariable logistic regression analysis demonstrated that age, gender, critical shoulder angle, glenoid version, diabetes mellitus, LHBT subluxation, subscapularis tear, and LHBT origin pattern were independently associated with RC tears. Using posterior LHBT origin as the reference category, supraglenoid tubercle origin (odds ratio, 0.27) and dual attachment (odds ratio, 0.28) were associated with lower odds of RC tears, indicating that posterior LHBT attachment was independently associated with an increased likelihood of RC tears (both P < .001). LHBT origin variations are independently associated with the presence of full-thickness RC tears. A posterior LHBT origin appears to be associated with a lower frequency of RC tears, suggesting that LHBT origin pattern may represent a potential morphologic marker of RC integrity.