Endoscopic carpal tunnel release: a cadaveric study.

Endoscopic carpal tunnel release was performed on 13 fresh-frozen cadavers using the Agee 3-M "Inside Job" Endoscopic Carpal Tunnel Release System, by a surgeon specifically trained in the technique and with a large clinical experience. Independent dissections showed no inadvertent lacerations to nerves, vessels, or tendons. The superficial palmar arch, the communicating branch between the ulnar and median nerves at the palm, and the common digital nerves to the third and fourth web spaces were the structures most at risk. Measurements of the distances between external landmarks were not helpful in accurately predicting the depth of blade insertion. In five of 13 cases there was complete release of the transverse carpal ligament. In four of the remaining eight cases fine fibers of the transverse carpal ligament or fascia connecting the thenar and hypothenar muscles were left over. In the other four cases there was an incomplete release of the transverse carpal ligament. The palmar fascia and more volar structures were preserved in the majority of cases.