A morphological study of third head of biceps brachii in human cadavers with its clinical implications

Abstract

Background: Muscular variations are relatively fewer when compared to vascular variations. A few muscles show extra heads of origin apart from their original heads. One such muscle which has extra heads of origin is biceps brachii (BB). Understanding of these extra heads is significant in handling injuries of the muscle and in tendon reconstruction operations. So, the aim of this study was to look for the incidence of the third head of the biceps brachii. Materials and Methods: The study was carried out on 24 cadaveric upper limbs. Dissection of the front of arm was done and the origin and insertion of the BB was looked. Any additional head if present was particularly looked for and photographed. Results: We found the three headed BB unilaterally in three male cadavers, one belonging to the left side and two to right side. The third head of BB originated near the insertion of the CB and at the origin of the brachialis in two cases and in both cases it goes and merges with the other two heads and insert into the posterior part of radial tuberosity. In one case it originates along with the long head of BB and its tendon goes and insert into the deep fascia of the arm. Conclusion : These all variations in the study should be known to the orthopedic surgeons during treatment of the bones fractures in this region because sometime the presence of third head may cause unusual bone displacement subsequent to fracture.