Radiological changes in juvenile chronic polyarthritis

Abstract

Although chronic arthritis in childhood is uncommon, evidence is accumulating that it comprises a heterogenous group of disorders. The term juvenile chronic polyarthritis, in preference to the older terms, juvenile rheumatoid arthritis (USA), Still's disease (UK), or juvenile progressive arthritis (Europe), has been used to describe the different entities now recognised, as well as rarer conditions such as psoriatic arthritis.

The radiological changes in these conditions are largely determined by the age of onset and type and pattern of the disease process. Thus in the 10% of patients with IgM rheumatoid factor persistently present, here termed seropositive juvenile rheumatoid arthritis, erosive changes occurred early and involved particularly the metacarpal and interphalangeal joints of the hands and metatarso-phalangeal joints of the feet. Without gold therapy, activity of the disease tended to continue with progressive destruction. Among the large group of seronegative patients, some 70% constitute the group previously called Still's disease (UK) and juvenile rheumatoid arthritis (USA). Three patterns of disease were recognised: (1) systemic illness which was not associated with early radiological joint change, (2) pauci-articular disease where growth anomalies were frequent, and (3) generalised polyarthritis. In the last, osteoporosis and periostitis could occur early, but the more specific changes of loss of articular cartilage and bone erosion developed later. Persistence of active joint disease was associated with a very high incidence of hip involvement, the changes in development varying according to the age at which the hip was affected. Because of the tendency to remit, healing could occur, but, particularly in the carpus and tarsus and the apophyseal joints of the neck, bony fusion was not infrequent as a sequel. In general, radiological abnormalities of the sacro-iliac joints were difficult to interpret in the adolescent, tending to occur late, as did the typical spinal changes of ankylosing spondylitis. In this last sub-group, large calcaneal spurs occurred commonly at a relatively early stage. The psoriatics warrant further attention, as in this condition the changes were asymmetrical and, while often mild, occasionally were associated with severe destruction occurring very rapidly in one or two joints.