To evaluate the prevalence and clinical associations of ultrasound (US) findings of inflammatory arthritis and joint and soft tissue pathology in patients with systemic sclerosis (SSc).
The hands and wrists of 43 SSc patients and 35 age-balanced controls were evaluated by clinical exam and musculoskeletal US. Synovial and tenosynovial pathology were assessed using semi-quantitative Gray Scale (GS) and Power Doppler (PD) scoring. US evaluation for osteophytes, erosions, ulnar artery occlusion, and median nerve cross-sectional areas was performed. Tender joints (TJ), swollen joints (SJ), modified Rodnan skin score (mRSS), digital ulcers, contractures, and calcinosis were evaluated. Concordance between US and physical exam findings at each joint region were assessed, and associations between their severity were analyzed.
TJs and SJs were present in 44.2% and 62.8% of SSc patients, respectively. Inflammatory arthritis, defined as having both GS>0 and PD>0, was observed in 18.6% of SSc patients and no controls. There was a high concordance by joint region between GS synovial hypertrophy and osteophytes (κ=0.88) as well as TJs (κ=0.72). SSc patients had more osteophytes compared to controls (48.8% vs 22.9%, p = 0.018) as well as higher osteophyte severity (p = 0.033).
Despite a high percentage of tender and swollen joints, less than 20% of SSc patients met criteria for inflammatory arthritis on US. The high concordance of osteophytes with GS synovial hypertrophy and tender joints suggest that osteophytosis may be a significant contributor to joint pain in SSc patients.