Diagnostic Performance of Acromiohumeral Distance on Routine Chest Radiographs: An Opportunistic Screening Approach for Rotator Cuff Pathology

Background: Rotator cuff disorders affect 30-40% of the general population [1,2], yet many cases remain undiagnosed. The acromiohumeral distance (AHD) on chest radiographs may serve as an opportunistic screening parameter, but its diagnostic utility has not been validated. Purpose: To determine the diagnostic accuracy of AHD measurements from routine chest radiographs in detecting rotator cuff pathology and establish optimal threshold values for screening. Methods: This cross-sectional study enrolled 120 patients (60 with MRI-confirmed rotator cuff tears, 60 controls) at a tertiary care hospital from January 2023 to December 2023. Two blinded observers measured AHD bilaterally on chest radiographs. Diagnostic performance metrics, receiver operating characteristic (ROC) curve analysis [8], and inter-observer reliability were calculated. Results: Mean AHD was significantly lower in the rotator cuff tear group (6.3±1.4 mm) compared to controls (8.4±1.1 mm, P