Fracture of the ulnar sesamoid bone of the thumb with a concurrent ulnar collateral ligament tear: A case report.

While the ulnar sesamoid bone of the thumb and the ulnar collateral ligament (UCL) are in close anatomic proximity, concurrent injury to these structures has not been reported. We report a case of such an injury in a 53-year-old male after an altercation. He was treated with surgical repair of the UCL, postoperative immobilization, and a graduated rehabilitation program consisting of range of motion and strengthening exercises. After review of the literature, we recommend that clinicians consider not just a volar plate injury, but also a UCL injury, in patients presenting with radiographic evidence of a sesamoid fracture. Clinicians should have a low threshold for advanced imaging in these patients to confirm any suspected ligamentous injury.