Subtalar arthralgia caused by juxtaarticular osteoid osteoma.

Juxtaarticular osteoid osteomas in the ankle are frequently misdiagnosed because their symptoms mimic arthritis and may precede roentgenographic findings. In addition, these tumors are rare compared to arthritis and other sources of ankle pain. Four cases of osteoid osteoma of the talus or calcaneus are reported, indicating some of the problems encountered with their identification, and suggestions are made for appropriate investigations to aid in the early and correct diagnosis. The use of plain tomograms, thin-section computed tomograms, and radionuclide scans aid an early and correct diagnosis. Arthroscopy and arthrotomy are often inappropriate.