Prevalence of various anomalies of costal element at cervico-thoracic junction in and around lucknow region of uttar pradesh: A radiological study.

Morphological diversities of the costal element at the cervico-thoracic junction adversely affect the positioning of its various neurovascular and soft tissue structures which form the etiological basis of symptoms in many cases of a non-traumatic type of Thoracic Outlet Syndrome (TOS). These rib variants represent disturbances of early organogenesis and are associated with stillbirths, childhood cancers, and several other congenital malformations. The present study aims to document the current prevalence, gender preferences, and laterality associations of various costal anomalies at the thoracic outlet in the reference population. A retrospective cross-sectional analytical study was conducted on 1474 PA skiagrams of the cervico-thoracic region, which comprised 919 males and 555 females of zero days to 73-year age. In 13.02% population, costal element exhibited anomalous development. Anomalies of the costal process of C7 vertebra showed higher(12.20%) prevalence compared to the thoracic first(0.81%). Elongation of the cervical 7 transverse process was most common(10.71%) followed by cervical rib(1.49%), rudimentary first rib (0.54%), and fusion of first and second ribs(0.27%). Cervical 7 costal anomalies showed a significant inclination towards females. No significant association with laterality and sidedness was observed for any of the anomalies. The study highlights a higher prevalence of an elongated transverse process of C7 compared to cervical rib and first rib anomalies in the reference population.