Sonoarthrographic examination of posterior labrocapsular structures of the shoulder joint

Objective: To describe the posterior labral lesions and labrocapsular abnormalities of the shoulder on sonoarthrography and to compare these findings with MR arthrography results. Methods: 82 shoulders were initially evaluated with ultrasonography and MRI and then were examined with sonoarthrography and MR arthrography following intraarticular injection of diluted gadolinium solution. The ultrasonography images were prospectively evaluated for the presence of posterior labral tear, sublabral cleft, and posterior capsular abnormalities by two radiologists. The diagnostic accuracy of sonoarthrography in the detection of posterior labral tears and posterior labrocapsular variants was compared with that of MR arthrography. Results: In sonoarthrographic examinations of 82 shoulders, 5 and 6 posterior labral tears were identified by Observer 1 and 2, respectively. Moreover, 6 and 7 posterior sublabral clefts, and 2 and 3 posterior synovial folds were identified by Observer 1 and 2, respectively. All the 82 patients were examined with MR arthrography; however, only 14 patients underwent arthroscopic examination. No significant difference was found among the 82 patients with regard to age, gender, and the prevalence of posterior labral tear, posterior labral cleft, and posterior synovial fold (p > 0.05). Interobserver variability showed substantial agreement between the sonoarthrographic and MR arthrographic results of the posterior labrocapsular structures (κ = 0.71, p < 0.05). Conclusion: Posterior labral tears and posterior synovial folds of the shoulder joint can be evaluated non-invasively by sonoarthrography. Advances in knowledge: Variations and pathologies of posterior labrocapsular structures of the glenohumeral joint are relatively uncommon. Direct (MR) arthrography is the gold-standard imaging modality to evaluate of posterior labrocapsular abnormalities of the glenohumeral joint. Sonoarthrography of the glenohumeral joint may be utilized in clinical practice in patients with contraindications to (MRI).