Hypothenar hammer syndrome caused by recreational sports activities and muscle anomaly in the wrist.

A 34-year-old man with digital ischemia is reported. Angiography revealed thromboembolic occlusions of the proper digital arteries of the index, middle, and ring fingers and a tortuous ulnar artery in Guyon's canal. Though hypothenar hammer syndrome was suspected, there was no relevant occupational history. Magnetic resonance imaging and magnetic resonance angiography demonstrated an anomalous muscular sling around the ulnar artery immediately adjacent to the hook of the hamate. The ulnar artery showed mural thrombi in its tortuous segment. These findings were confirmed during operative exploration. After thrombectomy and embolectomy the involved segment of the ulnar artery was replaced by an autologous vein graft. Postoperatively there was complete resolution of the symptoms. Only during convalescence did it become clear that the patient was a passionate golfer.