Blood supply in the bicipital groove: A histological analysis

The vascular anatomy in the closed bicipital groove with the long head of the biceps brachii muscle tendon (LHBT), its mesotenon and the transverse ligament intact has not been analyzed on a histological level yet. An anatomic dissection and histologic study was conducted by using 24 cadaveric formaldehyde fixated shoulders. The bicipital groove including the LHBT and its intact sheath was cut en-bloc, fixated, sliced in 7 μm sections, Azan stained and the vascular anatomy analyzed under light microscopy. Each sideward branch deriving from the main ascending branches of the anterior humeral circumflex artery (ACHA) in the mesotenon of the LHBT was identified and followed through multiple sections to identify its direction and area of supply. Per specimen, a mean of 2.71±1.85 branches could be identified running through the soft tissue of the mesotenon towards the osseous walls of the groove. Of the total 65 arterial branches in all specimens, 22 (33.8%) were running into the medial wall of the groove and 40 (61.5%) into the lateral wall (P<0.01). The results indicate that branches of the ACHA in the mesotenon of the LHBT provide blood supply not only to the tendon but to the osseous bicipital groove as well and here significantly more to the lateral than to the medial osseous wall. In addition, Pacini-like mechanoreceptors could be identified in the mesotenon in 9 (37.5%) of the specimens which has not been described up to now.