Interphalangeal Joint Sonography of Symptomatic Hand Osteoarthritis: Clinical and Functional Correlation.

OBJECTIVES: To assess the correlation between inflammatory sonographic findings (grayscale synovial hypertrophy and power Doppler) and clinical and functional assessments in hand osteoarthritis (symptomatic interphalangeal joints) and to correlate the intraobserver and interobserver reliability of these findings.

METHODS: A prospective double-blind study of 60 interphalangeal joints was conducted. The joints were assessed 6 times per year by clinician and sonographer observers.

RESULTS: A total of 720 measurement recesses were included (360 palmar and 360 dorsal). Small correlations and a few associations were found. Proximal interphalangeal joint quantitative measurements of the dorsal recess showed a statistical correlation with joint swelling (P = .043) and pulp-to-pulp pinch strength (P = .043); in the palmar recess, statistical correlations were seen for joint swelling (P = .007), the Australian/Canadian (AUSCAN) Function Index (P = .044), and grip and finger strength (P = .037, .003, .019, and .017). In dorsal semiquantitative assessments, there were associations between sonographic findings and joint swelling (P = .010) and pinch strength (P = .027, .003, and .014); in the palmar recess, we found associations with the AUSCAN Index (P = .048) and grip and finger strength (P = .031, .006, and 0.041). No correlations or associations were found in distal interphalangeal joints. Power Doppler signals were found in only 1.7% of the sample, precluding statistical analysis. Excluding palmar semiquantitative assessments in distal interphalangeal joints (P = .623), sonographic findings were reliable (intraclass correlation coefficients, 0.474-0.857; κ = 0.390-0.673).

CONCLUSIONS: Joint swelling, grip and pinch strength, and the AUSCAN Index were weakly correlated and associated with sonographic findings in proximal interphalangeal joints. Intraobserver and interobserver sonographic assessments were reliable.