Objectives: To investigate the bony morphologic characteristics of the bicipital groove and to determine their relations with the long head of the biceps tendon (LHBT) instability on magnetic resonance imaging (MRI). Methods: The depth of the bicipital groove (DBG), the medial wall angle (MWA) and the total opening angle (TOA) were measured on the shoulder MRI of 536 patients with anterior shoulder pain. 450 patients with a normally-located LHBT determined stable LHBT, 86 patients with subluxation or dislocation of the LHBT determined unstable LHBT. We assessed the relationship between measurements and LHBT stability and analyzed the cut-off values of the measurements to identify the long head of the biceps tendon instability. Results: The incidence of partial rotator cuff rupture, total rotator cuff tear, tendinosis and superior labral lesions were significantly higher in patients with unstable LHBT (p<0.05). In patients with unstable LHBT, DBG was shallower, medial wall angle was narrower and TOA was higher compared to those with stable LHBT. We recorded high sensitivity and specificities for the cut-off values of 5.65 mm for DBG 53.3° for MWA, and 87.1° for TOA to determine the presence of the unstable LHBT. Conclusion: DBG, MWA and TOA can be used as stability criteria for LHBT. Keywords: Bicipital groove, long head of the biceps tendon, magnetic resonance imaging, medial wall angle, groove depth, total opening angle
Corresponding Author: Kavak R.