Ulnar artery aneurysm and hypothenar hammer syndrome

Abstract

A right-hand dominant patient presented with pain and a tender mass in the hypothenar eminence, and with paraesthesia of the fourth and fifth fingers. The patient was referred for MRI of the hand, which showed thrombosed ulnar artery aneurysm and an irregularity of the superficial ulnar artery, suggesting a diagnosis of hypothenar hammer syndrome (HHS) (figures 1 and 2). Figure 1 Axial short tau inversion recovery image at the level of the hook of hamate (larger arrow) showing ulnar artery aneurysm (smaller arrow). Figure 2 Sagittal short tau inversion recovery image showing ulnar artery aneurysm (arrows). HHS results from repetitive microtrauma to the ulnar …