Inflammatory Versus Degenerative (Non Inflammatory) Ultrasound Detected Shoulder Abnormalities in Rheumatoid Arthritis Patients with Shoulder Pain

Abstract
Background: The early and definitive diagnosis of a chronic inflammatory joint disease in Rheumatoid Arthritis (RA) is crucial for initiating optimal treatment. Conventional radiography detects late changes such as joint destruction, but fails to visualize inflammation in synovial membrane.
Aim of Study: To compare type and frequency of Ultra-sound (US) abnormal findings (inflammatory versus degen-erative (non inflammatory)) detected in shoulders of RA patients with shoulder pain in relation to disease characteristics.
Patients and Methods: Musculoskeletal US (MSUS) shoulder examination and plain radiography were performed bilaterally for 45 RA patients and 45 controls with only painful shoulder and compared.
Results: Comparison between RA patients and controls in number (No) and frequency of inflammatory shoulder findings detected by MSUS (active bursitis, synovitis, teno-synovitis, erosions) revealed statistical significant difference (43 (47.8%) versus 18 (20.0%), respectively), p=0.000. There was no statistical significant difference between RA patients and controls in No. and frequency of non-inflammatory findings detected by MSUS (chronic bursitis, tendinopathy, tendon tears, osteophytes), (65 (72.2%) versus 60 (66.7%), respectively), p=0.418. In RA patients, inflammatory MSUS findings were significantly related to shoulder pain, older ages and higher ESR p<0.05. MSUS detected erosions in 42 (180) shoulders versus 6 (180) by X-ray, of the 42 MSUS detected erosions, X-ray detected only 4 (9.5%). Of the 138 MSUS-ve erosions, X-ray agreed in 136 (98.6%), kappa=0.115, p=0.01.
Conclusion: MSUS detected shoulder inflammatory ab-normalities are more frequent, symptomatic, usually bilateral in RA patients. They are related to shoulder pain, old age and disease activity. Early diagnosis of joint lesions by MSUS, proved superiority to conventional radiography, is crucial for initiating optimal treatment.