Irregularities at the base of the proximal phalanges: false indicator of early rheumatoid arthritis.

Fifty posteroanterior hand radiographs from normal adults were reviewed retrospectively to assess the incidence of cortical indistinctness at the base of the proximal phalanges in a normal population. This radiographic change, reported to be an early indicator of rheumatoid arthritis, was seen in at least one site in 10% of the films reviewed. Focal areas of cortical erosion or indistinctness at the bases of the proximal phalanges are not considered to be a reliable sign of early rheumatoid arthritis in the absence of juxtaarticular osteoporosis or changes in the metacarpal heads.