An osteological study of the clavicular facet of the coracoclavicular joint

The coracoclavicular joint is a rare diarthrotic synovial joint between the scapula and clavicle. Its presence has been established as an etiological factor in shoulder pain and could be associated with upper limb paraesthesia. The incidence of the joint varies in different ethnic populations. The present study aims to report the prevalence of this joint in South Indians. The descriptive study was conducted on 118 right-sided and 159 left-sided adult human dried clavicles. The conoid tubercle of the clavicles was examined for the presence of a smooth articular facet for the coracoid process of the scapula. The transverse and anteroposterior dimensions of the clavicular facet were measured using a digital Vernier caliper. The clavicular facet for the coracoclavicular joint was observed in 4.69% of the 277 bones. The shape of the facet was horizontally oval, and the transverse diameter was longer than the anteroposterior diameter. The mean transverse diameter was 8.81±1.86 mm, and the anteroposterior diameter was 6.16±2.39 mm. With a prevalence of 4.69% in this study in the South Indian population, the presence of CCJ could not be considered a rare anomaly. Although it is incidentally diagnosed, the possibility of CCJ occurrence should be considered in the differential diagnosis of unexplained shoulder pathology.