Erosion of the triquetrum and pisiform bones caused by a foreign body granuloma.

A 16-year-old boy had pain and swelling in the left wrist 6 months after he had fallen on a twig. Erosion of the triquetrum and pisiform was seen on x-ray films. A granulomatous process was identified at operation. Despite numerous cultures and special stains, no organisms were identified. Wood debris was seen under high-power magnification. A wooden foreign body may cause bone and joint destruction through a granulomatous process. In this case, surgical debridement and excision stopped the destructive process.