Morphology of the bicipital aponeurosis: a cadaveric study

Abstract

The bicipital aponeurosis (BA) is a fascial expansion which arises from the tendon of biceps brachii and dissipates some of the force away from its enthesis. It helps in dual action of biceps brachii as supinator and flexor of forearm. The aim of the present work was to study the morphology of BA. Thirty cadavericupper limbs (16 right and 14 left side limbs) were dissected and dimensions ofthe BA were noted. The average width of aponeurosis at its commencement on the right was 15.74 mm while on the left it was 17.57 mm. The average angle between tendon and aponeurosis on the right was 21.16° and on the left it was 21.78°. The fibres from the short head of the biceps brachii contributed to the formation of proximal part of aponeurosis. Fascial sheath over the tendon oflong head of biceps brachii was seen to form the distal part of the aponeurosis. In 5 cases, large fat globules were present between the sheath and the tendon. Histologically: The aponeurosis showed presence of thick collagen bundles. Fascials heath covering the tendon of long head extended towards the aponeurosis and passed superficial to the tendon of biceps. Blood vessels and adipose tissue were found to be present between fascial sheath and the tendon. This morphological description of BA may be helpful 1) in elucidating the dynamic role that BA plays in normal functioning and 2) to the surgeons in the repair of ruptured biceps brachii tendon.