Diagnostic and therapeutic value of ultrasonography in the detection of paralabral ganglion cysts with a curved array transducer: A case report.

Background: Paralabral cysts are a rare cause of shoulder pain. Linear ultrasound transducers are often used for musculoskeletal evaluation and intervention. However, the use of linear transducer is limited when the target structure is located deep and blocked by bony barriers, as is the case of paralabral ganglion cysts.

Objective: This case report aims to describe a beneficial role of using a convex transducer on the evaluation and ultrasonography-guided intervention of paralabral cysts below the acromion.

Case Description: Two patients visiting the outpatient clinic of Physical Medicine and Rehabilitation complained of severe pain during shoulder movement. Ultrasound scans with linear transducer detected rotator cuff lesions. Shoulder magnetic resonance imaging was done because of the persistent pain despite therapeutic interventions for the rotator cuff lesion, and confirmed paralabral cysts. Although a linear array transducer could not visualize the cystic lesion but could only perform suprascapular nerve block and intra-articular injection, the use of a convex array transducer improved the visualization of the cystic lesion which we treated using ultrasound-guided aspiration and intra-cystic injection. Visual analog scale and Shoulder Pain and Disability Index were checked to assess the treatment effect of each intervention. The intra-cystic injection with aspiration and intra-articular injection showed minimal to moderate improvement of pain score.

Conclusion: In pain related to shoulder movement, especially pain that continues despite appropriate treatment for rotator cuff lesions, ultrasound diagnosis of paralabral ganglion cysts using convex transducers will improve the diagnostic value and accuracy of intervention.