Osteoid Osteoma of the Ulnar Head―An Uncommon Cause of Ulnar Wrist Pain

Abstract

Nontraumatic ulnar-sided chronic pain can be divided into overuse injuries and chronic degenerative lesions. Osteoid osteomas represent 12% of all benign bone tumors. They are usually diagnosed in the second decade of life and show a male:female predominance of 2:1. 1 An upper limb location is less frequent, and they often mimic other typical upper limb diseases. 2 Because of this low frequency and tendency to mimicry, average diagnostic delays of 15-24 months have been described in the literature. 2,3 In this article we report on a patient with pain in the ulnar side of the wrist due to an osteoid osteoma on the head of the ulna, a cause that has never been described before. Case ReportA 52-year-old male patient, a manual worker, was referred to our institution due to chronic pain on the ulnar side of the right wrist, dominant side. The pain had gradually appeared 4 years before, with no known reason. The patient had previously been seen at another institution, where he was first treated by immobilization and nonsteroidal anti-inflammatory drugs (NSAIDs), but due to the lack of response to this treatment, which was repeated several times, and a positive radioulnar index diagnosed by plain X-ray imaging, ulnar shortening surgery was performed (►Fig. 1a,b). This intervention was also ineffective, and the symptoms persisted. A bone scan and computed tomography (CT) scan were requested, and the patient was referred to our institution.At the first visit the patient described pain on the ulnar side of the right wrist with functional limitation and loss of grip strength. The pain was worse at night and only partially relieved by NSAIDs. Physical examination showed only slight limitation of extension and ulnar deviation of the wrist, the rest of the examination being normal.On the plain X-ray image there was evidence of the ulnar shortening surgery performed, with no other finding (►Fig. 1b). Bone scan showed an area of increased uptake on the ulnar head (►Fig. 2a). CT showed exact location of the tumor and treatment plan (►Fig. 2b-d). The osteoid osteoma was located on the articular surface of the ulnar head, easily accessible in supination of the forearm (►Fig. 2c) through an anterior approach.In September 2010, a surgical procedure was performed under tourniquet using an anterior approach to the wrist on the radial border of the flexor carpi ulnaris (FCU) tendon. The AbstractBackground Osteoid osteoma of the wrist is rare and treatment is still in debate. Case Description We report on a patient with osteoid osteoma of the head of the ulna, as an unusual cause of pain on the ulnar side of the wrist. The diagnostic delay was 4 years. A previous ulna shortening surgery was performed because of misdiagnosis.The diagnosis was made with bone scan and computed tomography (CT). A surgical resection was performed. The symptoms disappeared, and full range of motion was recovered.Literature Review Osteoid osteoma on the head of the ulna had never been described before.Clinical Relevance This case demonstrates that osteoid oste...