The ulnar canal or ulnar tunnel, also called Guyon's canal, is a space at the wrist between the pisiform bone and the hamate bone through which the ulnar artery

Ulnar artery

The ulnar artery is the main blood vessel, with oxygenated blood, of the medial aspect of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins with the superficial branch of the radial artery...

 and the ulnar nerve

Ulnar nerve

In human anatomy, the ulnar nerve is a nerve which runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest unprotected nerve in the human body , so injury is common...

 travel into the hand.

Eponym

Guyon's canal was named after French surgeon

Surgeon

In medicine, a surgeon is a specialist in surgery. Surgery is a broad category of invasive medical treatment that involves the cutting of a body, whether human or animal, for a specific reason such as the removal of diseased tissue or to repair a tear or breakage...

 Jean Casimir Félix Guyon

Jean Casimir Félix Guyon

Jean Casimir Félix Guyon was a French surgeon and urologist born on Ile-Bourbon .He studied medicine in Paris, receiving his doctorate in 1858. He was appointed médecin des hôpitaux in 1864, and was later a professor of surgical pathology and genitourinary surgery at the University of Paris...

 (1831–1920). It is debatable whether he actually described the canal itself.

Clinical significance

Entrapment of the ulnar nerve

Ulnar nerve

In human anatomy, the ulnar nerve is a nerve which runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest unprotected nerve in the human body , so injury is common...

 at the ulnar canal can result in ulnar neuropathy. There are four subtypes of ulnar neuropathy

Ulnar neuropathy

Ulnar neuropathy is a disorder involving the ulnar nerve. Ulnar neuropathy may be caused by entrapment of the ulnar nerve at the elbow or wrist with resultant numbness and tingling into the fourth and fifth fingers....

 at the wrist, of which type II is the most common. Guyon's canal syndrome

Guyon's canal syndrome

Guyon's canal syndrome, sometimes referred to as Handlebar palsy, is caused by entrapment of the ulnar nerve in the Guyon canal as it passes through the wrist....

 may be secondary to ganglion cyst

Ganglion cyst

A ganglion cyst, also known as a bible cyst, is a swelling that often appears on or around joints and tendons in the hand or foot. The size of the ganglion or cyst can vary over time. It is most frequently located around the dorsum of the wrist and on the fingers...

 formation, or compression against a bicycle handlebar

Bicycle handlebar

Bicycle handlebar or often bicycle handlebars refers to the steering mechanism for bicycles; the equivalent of a steering wheel. Besides steering, handlebars also often support a portion of the rider's weight, depending on their riding position, and provide a convenient mounting place for brake...

.