- Discussion:
- 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:
- compresses sensory and motor aspects of the ulnar nerve as well as the motor innervation of the hypothenar muscles
-
zone 2 compression:
- the deep motor branch of the ulnar nerve is susceptible to compression;
- 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 thru 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 3 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.
