Clinical and pathologic studies of twenty-six patients with penetrating foreign body injury to the joints, bursae, and tendon sheaths.

Foreign body synovitis has been neglected in the rheumatology literature. We describe 26 patients in whom arthritis, bursitis, or tenosynovitis appeared within 1 day to 7 years after an initial injury by a penetrating foreign body. Twenty-two patients presented with acute synovitis, which was followed by chronic or recurrent inflammation mimicking septic arthritis, osteomyelitis, monarticular juvenile rheumatoid arthritis, bone tumor, or apatite deposition disease. Foreign bodies were not seen in 5 inflammatory synovial fluids studied, but were seen in the synovium or periarticular tissues of 17 patients. Excisional biopsy was required in most patients for precise diagnosis and treatment.