Hypothenar hammer syndrome: An uncommon cause of secondary syndrome and digital ischemia.

Hypothenar hammer syndrome affects less than 1% of the population, but if the diagnosis is delayed, digital gangrene and critical ischemia can ensue. The condition is caused by injury to the ulnar artery at the level of the hook of hamate when the palm of the hand is repetitively used as a hammer. Injury includes segmental occlusion of the ulnar artery and aneurysmal formation with or without occlusion. Patients with hypothenar hammer syndrome often present with symptoms of secondary Raynaud syndrome; if Raynaud is unilateral, a vascular origin should be suspected and ruled out. Treatment options for hypothenar hammer syndrome include conservative treatment measures, fibrinolysis, or surgical resection and repair, and depend on the specific injury and timing of diagnosis.