- Guyon (French Urologist) described this space in 1861;
- Guyon's canal is approximately 4 cm long beginning at the proximal extent of transverse carpal ligament and ends at the aponeurotic arch of hypothenar muscles;
- depression between pisiform & hook of hamate is converted into fibrosseous tunnel, the tunnel of Guyon, by pisohamate ligament;
- roof is formed by volar carpal ligament and pisohamate ligament;
- the ulnar nerve bifurcates within the canal into superficial and deep branches;
- deep branch of the ulnar nerve (more radial) and superficial branch more ulnar
- tunnel of Guyon is clinically significant because it contains ulnar nerve and artery & is site for compression injury;
- ulnar artery is immediately adjacent and radial to the ulnar nerve;
- consider anomalous muscles, ganglia, hamate fractures ect.
- zone 1 compression:
- extends from the proximal edge of the palmar carpal ligament to the bifurcation of the ulnar nerve
- compresses sensory and motor aspects of the ulnar nerve as well as the motor innervation of the hypothenar muscles
- zone 2 compression:
- extends from the bifurcation of the ulnar nerve just distal to the fibrous arch of the hypothenar muscles
- the deep motor branch of the ulnar nerve is susceptible to compression;
- zone 3 compression:
- contains the superficial sensory branch of the ulnar nerve;
- Technique of Decompression:
- the pisiform and the hamate are marked;
- a curvilinear incision is made between the pisiform and the hamate, and is extended proximally across the wrist crease and is then continued
along the medial border of the FCU;
- the ulnar nerve and artery are identified beneath the FCU;
- the deep dissection proceeds distally over the ulnar tunnel;
- incise through the palmaris brevis and palmar carpal ligament;
- examine the floor of Guyon's canal, and attempt to identify any anomalous muscles or ganglion cysts
Diagnosis of ganglion in Guyon's canal by magnetic resonance imaging.
The failed ulnar nerve transposition. Etiology and treatment.
Ulnar artery palmar to palmaris brevis: cadaveric study and three case reports.
Guyon's canal revisited: an anatomic study of the carpal ulnar neurovascular space.
General Orthopaedics: The Anatomy of the Distal Ulnar Tunnel.
Causes of ulnar tunnel syndrome: a retrospective study of 31 subjects.
Original Text by Clifford R. Wheeless, III, MD.
Last updated by Clifford R. Wheeless, III, MD on Sunday, April 26, 2015 4:09 pm