THE ULNAR NEUROVASCULAR BUNDLE AT THE WRIST - A TECHNICAL NOTE ON ENDOSCOPIC CARPAL-TUNNEL RELEASE

The boundaries of Guyon's canal have recently been redefined by a seri es of anatomical dissections. These showed that the confines of this s pace do not extend from the pisiform to the hook of the hamate, as cur rently accepted. The fascial roof extends radial to the hook of the ha mate, which allows the ulnar neurovascular bundle to course radial to the hamate hook. The position of the ulnar nerve and artery is of part icular significance for endoscopic carpal tunnel release. Most endosco pic devices are designed to divide the flexor retinaculum just to the radial aspect of the hamate hook. Utilizing cross-sectional analysis o f nine cadaver specimens, we found the ulnar artery to course radial t o the hamate hook in five and palmar to it in four. Therefore, the uln ar artery may be at greater risk of injury during endoscopic procedure s than previously recognized.