Coracoclavicular bursal changes on MRI: a diagnostic consideration in patients with shoulder pain and reduced coracoclavicular distance.

Objective: To describe MRI changes of the coracoclavicular bursa in patients presenting with shoulder pain and examine whether there is an association with coracoclavicular distance measurements.

Methods: Retrospective analysis of 198 shoulder 3T MRI scans for patients with shoulder pain was performed. Two musculoskeletal trained radiologists read all MRI scans. Inter-reader and intra-reader agreements for the bursal changes were assessed using the Kappa coefficient. The coracoclavicular distance was stratified into three intervals: < 5 mm, 5-10 mm, and > 10 mm. Statistical analysis for the coracoclavicular bursal changes and coracoclavicular distance was conducted using Fisher's exact test.

Results: Coracoclavicular bursal changes were detected in 9% (n = 18/198) of patients. There was a statistically significant association between coracoclavicular distance (< 5 mm) and the presence of coracoclavicular bursal changes (p-value = 0.011). All patients (100%, n = 18/18) with coracoclavicular bursal fluid presented with shoulder pain with 44.5% of the patients (n = 8/18) describing anterior shoulder pain. A statistically significant association was detected between coracoclavicular bursal changes and anterior shoulder pain (p-value = 0.0011). Kappa coefficient for the bursal changes inter-reader agreement was moderate (0.67) and the intra-reader agreement was almost perfect (0.91).

Conclusion: Coracoclavicular bursal changes were detected in 9% of shoulder MRI scans and were associated with reduced coracoclavicular distance (< 5 mm) suggesting an underlying mechanical disorder such as a friction or an impingement process. Documenting coracoclavicular bursal changes in the MRI report could help address patients' concerns and guide further management particularly in the context of shoulder pain and coracoclavicular distance of less than 5 mm.