Rhomboid fossa in the clavicles of North Indians.

The incidence and size of the rhomboid fossa were studied in paired clavicles of North Indians obtained from 20 neonates, 60 children, and 789 adult bodies of known age and sex on which postmortem examinations had been performed by the senior author (except in cases of neonates). The fossa was absent in the newborns but was present bilaterally in 44% of male and 54% of female children below 18 years of age and in 16.5% of male and 20.8% of female children unilaterally. Statistically the sexual differences were not significant (P greater than 0.05). In the adults, the incidence of bilateral fossa was 58.70% in males and 54.14% in females and a unilateral fossa was seen in 13.29% of males and 16.56% of females, but the sexual difference in both cases was insignificant (P greater than 0.05). However, in unilateral cases, the incidence of the fossa was greater on the right than on the left side in both male (P less than 0.001) and female (P less than 0.001) bones. Although racial differences cannot be ruled out, no sexual or side differences in the incidence of the fossa could be found. Factors responsible for creating a deep fossa unilaterally are not understood.