The ulnar canal or ulnar tunnel (also known as Guyon's canal or tunnel) is a semi-rigid longitudinal canal in the wrist that allows passage of the ulnar artery and ulnar nerve into the hand.[1] (These are named after the ulna, the long bone on the little finger side of the arm.) The roof of the canal is made up of the superficial palmar carpal ligament, while the deeper flexor retinaculum and hypothenar muscles comprise the floor. The space is medially bounded by the pisiform and pisohamate ligament more proximally, and laterally bounded by the hook of the hamate more distally.[2][3] It is approximately 4 cm long, beginning proximally at the transverse carpal ligament and ending at the aponeurotic arch of the hypothenar muscles.[4]

Ulnar canal
Transverse section across the wrist and digits.
Superficial palmar nerves.
Latincanalis ulnaris
Anatomical terminology

Eponym edit

The ulnar tunnel is named after the French surgeon Jean Casimir Félix Guyon, who originally described the canal in 1861.[5]

Clinical significance edit

Entrapment of the ulnar nerve at the ulnar canal can result in symptoms of ulnar neuropathy, including numbness or weakness of certain parts of the hand.[6] (See full article on ulnar nerve entrapment.) This is known as ulnar nerve entrapment or Guyon's canal syndrome. There are four subtypes of ulnar neuropathy at the wrist, of which type II is the most common. Guyon's canal syndrome[7] may be secondary to ganglion cyst formation, or compression against a bicycle handlebar.

See also edit

References edit

  1. ^ Stanley Hoppenfeld; Michael S. Zeide (1994). Orthopaedic Dictionary. Lippincott Williams & Wilkins. ISBN 978-0-397-51311-6.
  2. ^ Hatch, Daniel (Aug 20, 2014). "Ulnar Tunnel Syndrome". Orthobullets.
  3. ^ James R. Doyle (2003). Surgical Anatomy of the Hand and Upper Extremity. Lippincott Williams & Wilkins. pp. 682–. ISBN 978-0-397-51725-1.
  4. ^ Wheeless, III, Clifford R. (Dec 21, 2012). "Tunnel of Guyon". Wheeless' Textbook of Orthopaedics. Duke Orthopaedics.
  5. ^ Guyon, Felix (1861). "Note sur une disposition anatomique propere a la face anterieure de la region du poignet et non encore decrite". Bull Soc Anat Paris. 6: 184–186.
  6. ^ Shea, JD; McClain, EJ (1969). "Ulnar-nerve compression syndromes at and below the wrist". The Journal of Bone and Joint Surgery. American Volume. 51 (6): 1095–103. doi:10.2106/00004623-196951060-00004. PMID 5805411.
  7. ^ Aleksenko, Dmitri; Dulebohn, Scott C. (2018). StatPearls. Treasure Island (FL): StatPearls Publishing. PMID 28613717.