Synovitis of the wrist joint caused by an intraarticular perforation of an osteoid osteoma of the scaphoid

Uncommon location and atypical presentation of the osteoid osteomas of the scaphoid can pose a diagnostic challenge. Because of its intraarticular location, scaphoid osteoid osteoma can present with synovitis which is the more commonly reported presentation for other intraarticular locations like in hip and elbow and only rarely reported at the wrist. We report a case of perforation of the osteoid osteoma into the wrist joint, resulting in exuberant synovitis. The clinical significance of this report is to reinforce that synovitis can be a presentation of osteoid osteoma and it should be considered in the differential diagnosis of monoarticular arthritis. Prolonged synovitis may cause damage to the other joint surfaces of the wrist and hence carpal osteoid osteoma should be considered for early surgical excision.