Prevalence and Morphology of the Coracoclavicular Joint: An Osteological Study of 2,724 Subjects Using Univariable and Multivariable Logistic Regression Analyses

Background: The coracoclavicular joint (CCJ) is an anomalous articulation between the surfaces of the inferior clavicle and superior coracoid and its etiology is controversial. Reportedly, symptomatic patients demonstrate significant functional limitations including shoulder abduction loss and potential for brachial plexus compression and impingement.Purpose: To determine the prevalence of CCJ across age, gender and ethnicity, and to identify clinically useful morphological characteristics.Methods: 2,724 subjects with intact clavicles and scapulae from the Hamann-Todd Osteological Collection were evaluated for the presence of CCJ. Logistic regression was used to determine the effect of age, height, gender, and race on prevalence of CCJ. 354 clavicles with CCJ were measured for size and location of the CCJ facet.Results: CCJ was observed in 9% of subjects. CCJ was more prevalent in African-Americans (12%) than Caucasian-Americans (6%) (p < 0.001) and more prevalent in females (11%) than males (8%) (p = 0.055). Facet location along clavicle length was consistent (average 25%, range 15–35%). But, facet location along clavicle width varied (average 60%, range 10–90%), with males having a more posterior location. For every 10-year increase in age, facet elevation (p = 0.001) and surface area (p < 0.001) increased.Conclusions: CCJ prevalence was 9% in our large osseous population, found more commonly in African-Americans and females. Facet location is predictable with respect to clavicle length, but less so along clavicle width. The clavicular facet may develop at some point in life and continue to grow in size after its appearance.Clinical Relevance: Presence of a CCJ represents a potential overlooked source of anterior shoulder pain and supracoracoid impingement. Epidemiologic and morphological characteristics presented in our study can aid in the identification, clinical understanding, and surgical excision of a symptomatic CCJ. Level of Evidence: Level IV.

Prevalence of Coracoclavicular Joint in Patients Visiting Radio-Diagnosis Department at College of Medical Sciences, Chitwan

Introduction: Coracoclavicular joint (CCJ) is a true synovial joint between su­perior surface of coracoid process of scapula and conoid tubercle of clavicle. The radiological prevalence of CCJ in various population ranges 0.55% to 21%. The CCJ are mostly discovered incidentally and is rarely associated with any symptom. Sometimes it may present with shoulder pain, limitation of shoulder movement, upper limb paresthesia and osteoarthritis of itself or adjacent ac­romioclavicular joint. Hence, this study is aiming to determine the prevalence of anomalous CCJ in patient visiting department of Radio-diagnosis in College of Medical Sciences, Bharatpur, Chitwan, Nepal and to observe association of CCJ with laterality, sides and gender. Methods: A total of 1936 digital chest x-rays films were observed for the pres­ence of CCJ, out of which 1097 images were of male and 839 of females. Age of study population ranged from 3 to 90 years. The data obtained were analyzed using Stastical Package for Social Science version (SPSS) 16.0. The prevalence of CCJ was calculated. The cases with CCJ were further analyzed to evaluate the association of CCJ with laterality, sidedness and gender using Chi-square for one-dimensional “goodness of fit” test. Chi-square of Independence was em­ployed to compare the various parameters (laterality and side) with genders. Results: The prevalence of CCJ was 4.6%. CCJ was more frequently observed in male (67.42%) than female (32.57%). Unilateral occurrence of CCJ (55.06%) was slightly more than bilateral (44.94%). Gender difference was not signifi­cantly associated with laterality and sidedness of joint (p<0.05). The incidence of CCJ was more in second decade of life in both male and female. Conclusion: CCJ is not rare, hence, knowledge of presence of CCJ as an etiol­ogy of shoulder pain is essential for rational therapy and will prevent misdiag­nosis.