Intra-articular osteoid osteoma at the elbow: report of a case and review of the literature.

Osteoid osteoma is a benign tumor that may occur in almost any part of any bone. Diagnosis can be difficult, particularly when it is intra-articular. In these cases, osteoid osteoma may present initially with symptoms suggestive of inflammatory arthritis, degenerative joint disease, neoplasm, or infection. We report a case of intra-articular osteoid osteoma in a teenager who presented with a monoarthritis of the elbow. The patient did not have a typical pattern of pain, did not have the typical relief with anti-inflammatory agents, and misinterpretation of the radiographs led to a delay in the diagnosis and definitive treatment. Surgical excision confirmed the diagnosis and resulted in resolution of the monoarthritis. Intra-articular osteoid osteoma must be taken into account in cases of unexplained chronic monoarthritis, with a sterile and relatively noninflammatory synovial fluid. A definitive diagnosis depends on surgical excision and histologic confirmation. Ahigh index of suspicion is necessary to make the diagnosis.