A Cadaveric study on Rectus Sternalis muscle and its clinical significance in Western part of Tamilnadu state (Kongunadu region)

Abstract

Background: Rectus sternalis is considered as an unusual accessory or supernumerary muscle which appears either unilateral or bilateral in the anterior thoracic wall of human beings. It varies in length, breadth, thickness and incidence among different races and in both sexes. Regarding its origin and insertion still a clear conclusion has not been reached because some authors says it originates and ascends for insertion while some of them opines it originates and descends for insertion. Clinically, its presence also leads to false diagnosis such as Breast tumours, lipoma etc. Aim of the study: To find out the presence of Rectus sternalis muscle in the anterior chest wall during routine dissection. Materials and Methods: 37 well embalmed and preserved cadavers of both sexes which is used for routine dissection to Phase-I MBBS students were taken into condideration. The pectoral region on either side of sternum was dissected in layers and visualised for the presence of Rectus sternalis. Results: Among 37 cadavers dissected, Rectus sternalis was found in the pectoral region of a male and a female cadaver. In male it appeared bilateral, whereas in female it is unilateral. In both the cases it lie superficial to pectoralis major. Conclusion: The incidence of Rectus sternalis reported from our study was 5.4%. In the earlier days it lead to misdiagnosis and made great challenge to radiologists and surgeons, but now-a days with advancement in imaging techniques its presence can be detected clearly thus avoiding unnecessary expenditure and invitro techniques. Clinically it is also used as pedicle flap in breast reconstructive surgeries. KEY WORDS: Cadaver, Dissection, Pectoral region, Rectus sternalis, sternocleidomastoid.