Endoscopic Release of the Guyon Canal and Pisohamate Hiatus

The ulnar nerve runs in more than 1 tunnel in the wrist. Ulnar nerve entrapment in the wrist can occur at the Guyon canal and the pisohamate hiatus. Open release of these 2 tunnels requires a lengthy incision and extensive soft-tissue dissection. The purpose of this technical note was to describe the details of endoscopic release of the Guyon canal and the pisohamate hiatus. This minimally invasive approach allows release of the ulnar nerve and its motor branch at the wrist level.