Guyon's canal refers to a potential space in the wrist between the two bones (the pisiform and hamate) and the ligament that connects them. Ulnar artery and nerve travel through this space. Entrapment of the ulnar nerve at the Guyon's canal can result in ulnar neuropathy at the wrist. There are 4 subtypes of ulnar neuropathy at the wrist, of which type II is the most common. Guyon's canal entrapment syndrome may be secondary to ganglion cyst or compression against cycling handlebar.

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