Study of the anomalies associated with the human sterna in south indian population

Objectives: To study the variations in adult human sterna. Knowledge of sternal anomalies helps in understanding its importance in cardiac surgery, Radiology, genetics, Acupuncture and Medico legal fields. It helps in understanding and analyzing the level of involvement of enthesial regions in autoimmune or degenerative disorders. Materials and Methods: The study was conducted on 75 dry sterna, collected from the Medical students, in the departments of anatomy, M.S. Ramaiah Medical College, Bengaluru, IMS, MSU, Bengaluru campus, during the last seven years. The sterna were examined for the presence of anomalies like sternal foramina and synostosis. Results: Of the 75 sterna studied, 5 bones presented with sternal foramina, which were more near the lower half of the body of the sternum, 7 Manubriosternal fusions, 6 xiphisternal fusions, six bones with chondrosternal synostosis, two with sternocostal synostosis. The xiphoid process presented variations like bifid, single and pointed, quadrilateral. More than one anomaly were seen in one sternum. Conclusion: The causes of sternal foramina have been mentioned as nonfusion or incomplete fusion of the developing sternum from two cartilaginous bars. If there is complete nonfusion, there will be a midline fissure with two separate halves of sternal bone. The fusion of sternum with bones and cartilages articulating with it are probably due to degenerative disorders like DISH (Degenerative Idiopathetic Skeletal Hyperostosis), The chondrocalcinosis also has been attributed to some genetic factors like ‘ank’ gene, variant of ‘ank’ gene called ‘ANKH’ gene present in 5p and 8q chromosomes. Another gene called ENPP1 responsible for soft tissue calcification has been identified.