Comparison between Several Ultrasound Hand Joint Scores and Conventional Radiography in Diagnosing Hand Osteoarthritis

This is the first study to investigate the usefulness of a standardized ultrasound (US) examination protocol in diagnosing hand osteoarthritis (OA). We conducted a cross-sectional study including 62 patients, ultimately diagnosed with hand OA based on imaging evidence of osteoarthritic changes with the particular distribution required for fulfilment of American College of Radiology diagnosis criteria. We compared a 32-joint US score (wrists, metacarpophalangeal [MCP], proximal interphalangeal [PIP] or distal interphalangeal [DIP] and carpometacarpal [CMC]-1 joints), with smaller, predefined joint scores, assessing 22 joints (wrists, MCPs and PIPs or PIPs, DIPs and CMC-1), 10 joints (MCP 2-3, PIP 2-3 and CMC-1 or PIP 2-3, DIP 2-3 and CMC-1) and 6 joints (DIP 2-3, CMC-1), respectively. The US findings were correlated with radiographic scores for erosions and osteophytes. Radiographic osteophyte scores correlated well with all the US scores mentioned earlier (R = 0.381 to 0.645, p < 0.05), despite low sensitivity for detection of osteophytes (43.5%) and erosions (28.9%), compared with the 32 joint US score. Both 10 joint US protocols (assessing MCP 2-3, PIP 2-3 and CMC-1 or PIP 2-3, DIP 2-3 and CMC-1 joints) performed better than conventional radiography, by identifying osteophytes in an additional 25.6% and 23.9% of patients, respectively. The conclusion of this study is that the US examination of 10 preselected hand joints is more sensitive than conventional radiography in diagnosing hand OA in patients who do not fulfill American College of Radiology clinical criteria, a finding likely to have practical implications for facilitating diagnosis of hand OA.