We would like to highlight on the importance of a coracoclavicular joint being a rare synovial anomalous diarthrosis formed between the conoid tubercle of the clavicle and the superior surface of the horizontal part of the coracoid process of the scapula. It was first described in 1861 by Gruber. Kaur & Jit have studied the presence of a coracoclavicular joint in paired clavicles obtained from 1,000 adult subjects of northwest Indian population [1]. The coracoclavicular joint has been recognized as an uncommon osteological feature [2]. The incidence of coracoclavicular joint is more common in Asians than in Europeans or Africans [3,4]. It usually become symptomatic in adulthood and the probable etiology could be an underlying arthrosis of this synovial diarthrosis with advancing age. Surgical excision of a symptomatic congenital coracoclavicular joint in a patient has been described in the literature in a resistant case not responding to a conservative management [5]. Clinical symptoms usually are limited to pain around the shoulder joint mainly with hyperabduction. Very rarely it may present as thoracic outlet syndrome. The differential diagnosis includes an osteochondroma, post traumatic myositis ossificans. The recognition of a synovial joint between the conoid tubercle of clavicle and coracoid process of scapula indicates coracoclavicular joint and differentiates from osteochondroma and post traumatic myositis ossificans (Figures 1-3).

Figure 1: X-ray shows right coracoclavicular joint.

Figure 2: CT scan (MPR) showing right coracoclavicular joint.

Figure 3: T1Weighted Coronal image showing synovial right coracoclavicular joint.

We wish to emphasize that both the clinicians and radiologist should be aware of the entity to properly diagnose it and accordingly treat the patient who comes with undiagnosed shoulder pain.