Functional changes of the long head of the biceps brachii (LHB) tendon with rotator cuff tears are not well known though they presents various pathological changes. Optimal treatments for pathological LHB tendons are not well established. The purpose of this study was to assess morphology and localization of the LHB tendons with rotator cuff tears. We retrospectively evaluated MR arthrographies of 47 shoulders in 46 patients with surgically treated full thickness rotator cuff tears, and 8 shoulders in 8 people without a rotator cuff tear as control. Morphology and localization of the LHB tendon were evaluated with oblique sagittal images in the 4mm lateral plane parallel to the glenoid fossa. We measured three parameters: LHBw: the width of the LHB, LHBt: the thickness of the LHB and LHBa: the anterior displacement angle of the LHB. We analysed three parameters in four groups determined by the rotator cuff tear size: No tear (N), small (S), middle (M) and large (L). The average measurements were 9.60,9.60,10.42 and 12.22 respectively in LHBw,2.10,2.93,3.49 and 4.20 respectively in LHBt; 17.58,17.52,20.94 and 25.36 respectively in LHBa. The width and thickness of LHB tendons increased with the increase of rotator cuff tear size; the LHB tendons were displaced more anteriorly in the same manner.
