The relation between synovitis of individual finger joints and grip force over the first 5 years in early rheumatoid arthritis - a cohort study.

MCP I synovitis is the major contributor to reduced grip force in patients with early RA. This underlines the importance of the involvement of the thumb for impaired hand function in RA. MCP IV synovitis, but not PIP involvement or finger joint tenderness, also has a substantial impact on grip force.