Background Hand osteoarthritis (HOA) is a common and frequent cause of pain. HOA is a heterogeneous group of disorders with two main subsets including non-erosive and erosive disease. Few studies demonstrated inflammatory ultrasound changes and more severe clinical symptoms in patients with erosive compared with non-erosive disease, however the results are inconsistent.
Objectives he aim of this study was to evaluate progression of pain, stiffness, physical impairment and ultrasound features in patients with erosive and non-erosive HOA in a two years longitudinal study.
Methods Consecutive patients with symptomatic HOA fulfilling the American College of Rheumatology (ACR) criteria were included in this study. Joint pain and swelling were assessed. Patients reported joint pain on 100 mm visual analogue scale (VAS). Pain, joint stiffness and disability were assessed by the Australian/Canadian OA hand index (AUSCAN). Radiographs of both hands were examined and erosive disease was defined by at least one erosive interphalangeal joint. Synovial hypertrophy and power Doppler signal (PDS) were scored with ultrasound. Synovitis was graded on a scale of 0–3 and osteophytes were defined as cortical protrusions seen in two planes. Patients were examined at baseline and at the two years follow-up.
Results Altogether, 129 patients (12 male) with symptomatic nodal HOA were included in this study and followed between April 2012 and January 2017. Out of these patients, 72 had erosive disease. The disease duration (p<0.01) was significantly higher in patients with erosive compared with non-erosive disease.
Pain (p<0.05) and the number of clinically swollen joints (p<0.05) were significantly higher in patients with erosive compared with non-erosive disease at baseline. There were significant progression of pain (p<0.05) and the number of clinically swollen joints (p<0.01) at the two years follow up. The progression in clinically swollen joint count was about 21% higher in patients with erosive disease.
According to the AUSCAN, patients with erosive compared with non-erosive disease had more pain (p<0.05) and stiffness (p<0.01) at baseline. Pain and stiffness, but not function, got worse (p<0.01) in patients with erosive compared with non-erosive disease at the two years follow up.
US-detected pathologies such as gray-scale synovitis total score (p<0.001), intensity of PDS (p<0.01) and number of osteophytes (p<0.01) were significantly higher in patients with erosive compared with non-erosive disease at baseline. There were improvements in gray-scale synovitis total score and intensity of PDS in patients with non-erosive disease while patients with erosive disease worsened at the two years follow up. On the other hand, the progression of US-determined osteophyte formation was observed in both groups.
Conclusions The findings of this study show that pain and number of clinically swollen joints associated with US-detected synovial hypertrophy inflammatory signs and osteophyte formation is more severe in patients with erosive HOA than in patients with non-erosive disease. In addition, osteophyte formation is more likely to progress independent of synovial inflammation.
Acknowledgements This work was supported by the project (Ministry of Health, Czech Republic) for consensual development of research organization 023728.
Disclosure of Interest None declared