Shoulder involvement in rheumatic diseases. Sonographic findings

Area of Science:

• Musculoskeletal imaging
• Rheumatology
• Diagnostic ultrasound

Background:

• Rheumatoid arthritis (RA), polymyalgia rheumatica (PMR), and periarticular disorders (PD) can present with overlapping shoulder symptoms.
• Accurate differentiation is crucial for appropriate treatment and management of shoulder soft tissue conditions.
• Shoulder sonography offers a non-invasive method for evaluating soft tissue structures.

Purpose of the Study:

• To utilize shoulder sonography to differentiate the sonographic changes associated with RA, PMR, and PD.
• To identify specific sonographic markers for each condition to improve diagnostic accuracy.

Main Methods:

• Sonographic evaluation of 90 shoulders with RA, 32 with PMR, 122 with PD, and 108 controls using a 7.5 MHz linear probe.
• Assessment of key shoulder structures including tendons (biceps, rotator cuff), bursae, joints (glenohumeral, acromioclavicular), and presence of calcifications.
• Statistical analysis employing Student's t test and chi-squared test to compare findings between groups.

Main Results:

• Significant differences in long head of biceps tendon involvement were observed between RA and PMR, and between PD and PMR.
• Rotator cuff tendon alterations showed significant differences, particularly supraspinatus and subscapularis tendons, between PD and other groups.
• Glenohumeral joint effusion and acromioclavicular joint effusion were significantly different between RA/PMR and controls/PD, with calcifications noted primarily in PD and RA.

Conclusions:

• Shoulder sonography demonstrates characteristic findings for RA, PMR, and PD.
• RA involves all evaluated shoulder structures, PMR shows a prevalence of effusion, and PD primarily affects tendons.
• Sonographic evaluation aids in distinguishing these shoulder pathologies, supporting clinical diagnosis.