What tendon must have a complete full-thickness tear to allow for this degree of dislocation?
Subscapularis
In normal anatomical relationships, the proximal LHBT is held in place at the rotator cuff interval by what structures?
It is held in place by a sling formed by the superior glenohumeral ligament and the coracohumeral ligament.
There is a massive full-thickness tear involving nearly the entirety of the rotator cuff with dislocation of the long head of the biceps tendon into the glenohumeral joint. There is also masseration of the glenoid labrum with extensive joint effusion mimicking a contrast arthrogram, with evolving hemorrage inferiorly and laterally to the humerus under the delotid. The humerus is superiorly subluxed with patchy marrow edema.