In erosive hand osteoarthritis more inflammatory signs on ultrasound are found than in the rest of hand osteoarthritis.

OBJECTIVE

To compare inflammation as assessed by ultrasound between patients with the subset erosive hand osteoarthritis (EOA) versus non-EOA.

METHODS

Consecutive hand osteoarthritis (HOA) patients (fulfilling ACR criteria) were included. Eighteen interphalangeal joints were scored on radiographs using the Verbruggen-Veys anatomical phase score; E and R phases were defined as erosive. Patients were assigned to EOA when at least one joint was erosive. Effusion, synovial thickening and power Doppler signal (PDS) were scored with ultrasound on a 4-point scale. Generalised estimated equation analyses were used to compare ultrasound features between EOA and HOA, and to associate ultrasound features with.anatomical phases; OR with 95% CI were calculated with adjustments for patient effects and confounders.

RESULTS

Of 55 HOA patients (mean age 61 years, 86% women) 51% had EOA. In 94 erosive joints, synovial thickening, effusion and PDS were found in 13%, 50% and 15%, respectively; in 896 non-erosive joints in 10%, 26% and 8%, respectively. In summated scores of PDS, effusion was higher in EOA than in non-EOA. Effusion and synovial thickening were more frequent in S, J, E and R phases compared to N phase. PDS was only associated with E phase (OR 5.3, 95% CI 1.3 to 20.5) not with other phases. Non-erosive joints in EOA demonstrated more PDS (OR 3.2, 95% CI 1.6 to 6.4) and effusion (OR 2.2, 95% CI 1.2 to 3.8) in comparison to joints in non-EOA.

CONCLUSIONS

Inflammatory signs are more frequent in EOA than in non-EOA, not only in erosive joints but also in non-erosive joints, suggesting an underlying systemic cause for erosive evolution.