Muscle atrophy and leg length discrepancies in pauciarticular juvenile rheumatoid arthritis.

In 32 children with pauciarticular juvenile rheumatoid arthritis, we studied residual muscle atrophy and leg length discrepancy after the arthritis had entered remission. Children under the age of 3 years at disease onset had significantly more muscle atrophy and bone overgrowth than children whose disease began after the age of 3 years. These residua have cosmetic and functional significance, and new methods of treatment will be necessary to prevent or reverse the sequelae in a form of arthritis previously thought to have a benign outcome.