The Onset of Subtalar Joint Monoarthritis in a Patient with Rheumatoid Arthritis.

The involvement of the subtalar joint is uncommon in the early stages of rheumatoid arthritis (RA). We report a case of a 47-year-old female who had RA with isolated subtalar joint arthritis. The clinical history, magnetic resonance imaging, and pathological findings of the patient are presented. A careful evaluation of the patients for chronic ankle-to-heel pain should be conducted, and concomitant evaluation for inflammatory arthritis, including RA, should be considered.