Effect of dominancy on severity in rheumatoid arthritis

Joint use has been felt to increase the severity of rheumatoid synovitis. Ninety-three patients with definite or classical rheumatoid arthritis (RA) were studied blind for clinical and radiological findings to see the effect of dominancy on the severity of the arthritis. The dominant side showed significantly greater total swelling scores (P less than 0.0001) and total tenderness scores (P less than 0.01). This was explained predominantly by greater severity of arthritis in dominant arms and hands. X-rays of the dominant hands and wrists showed more joint space narrowing (P less than 0.04) and erosion (P less than 0.01), but no differences in malalignment scores. There were no differences between dominant and non-dominant sides on frequency of intra-articular injections or use of splinting, but the dominant side received more surgical operations (P less than 0.02).