Evaluation of Preoperative Magnetic Resonance Imaging Parameters with Arthroscopic Validation of Subscapularis Tendon Abnormalities in 187 Patients at a Single Center in Turkey

BACKGROUND: This study from a single center in Turkey aimed to evaluate preoperative magnetic resonance imaging (MRI) parameters with arthroscopic validation of subscapularis (SS) tendon abnormalities in 187 patients. MATERIAL/METHODS: Preoperative MRI scans of 187 patients who had undergone arthroscopic shoulder surgery by the senior author (all in lateral decubitus position) were evaluated by 3 researchers. Patients with arthroscopically proven SS tendon rupture (n=69) and without rupture (n=118) were divided into 2 groups and compared with various distances and angles. The following parameters were measured: coracohumeral distance (CHD), coracoid morphology, coraco-glenoid angle (CGA), coracoid angle (CA), coraco-humeral angle (CHA), coracoid overlap (CO), coracoid body-glenoid angle (CBGA), coracoid tip-glenoid angle (CTGA), coracoid tip-body angle (CTBA), coraco-scapular angle (CSA), lesser tuberosity angle (LTA), and lesser tuberosity height (LTH). RESULTS: CHD, CHA, CA, and LTA values decreased in the SS tendon rupture group; coracoid type grade and CO increased (all P<0.001, excluding LTA [P=0.022]). The cut-off values of these measurements were CHD=7.25 mm, CHA=107.25°, CA=111.5°, LTA=31.7°, and CO=16.5 mm. The differences in CGA and CBGA values were not statistically significant (P=0.11, 0.441, respectively). CTGA, CTBA, LTH, and CSA measurements were not included in the intergroup comparisons due to insufficient inter-observer reliability (κ=0.478, 0.239, 0.496, 0.309, respectively). Power (1-b) in post hoc analysis was calculated as 0.941. CONCLUSIONS: SS tendon rupture was associated with a reduction in the parameters of CHD, CHA, CA, and LTA and an increase in CO on MRI.