Incidence of joint involvement in early rheumatoid arthritis.

The frequency of joint involvement is described in 102 patients seen within one year of onset of rheumatoid arthritis. The joints most commonly affected were metacarpophalangeal, proximal interphalangeal and wrists, followed by metatarsophalangeal and shoulders. The least commonly affected were the hips and spine. Temporomandibular and cervical spine involvement often occurred even in these early stages. Where there was unilateral involvement of corresponding joints there was a marked tendency for one side of the body to be more often affected. The arthritis was predominantly peripheral. There was a marked gradation of frequency in the small joints of the hands. The patients were followed prospectively for a mean 4.5 years and outcome assessed. An eventually more severe disease was associated with early writst and metatarsophalangeal joint involvement.