The ulnar (Guyon’s) canal is a fibro-osseous tunnel located at the level of the palm. It transmits the ulnar neurovascular bundle from the forearm into the hand. In this article, we shall look at the anatomy of the ulnar canal – its borders, contents, and clinical relevance. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Borders The ulnar canal is approximately 4cm in length. It extends from the proximal aspect of the pisiform bone to the origin of the hypothenar muscles at the hook of hamate. Its borders consist of: Medial (ulnar) – pisiform, flexor carpi ulnaris tendon, abductor digiti minimi muscle. Lateral (radial) – hook of hamate. Roof – palmar carpal ligament. Floor – flexor retinaculum, pisohamate ligament, and hypothenar muscles. Adobe Stock, Licensed to TeachMeSeries Ltd Fig 1The borders of the ulnar canal Pro Feature - Dissection Images Superficial dissection of the hand and wrist - demonstrating the median nerve, ulnar nerve and arterial supply. Superficial dissection of the hand and wrist - demonstrating the median nerve, ulnar nerve and arterial supply. You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More Contents The ulnar canal conveys the ulnar neurovascular bundle into the hand: Ulnar nerve – bifurcates within the canal into superficial (sensory) and deep (motor) branches. Ulnar artery – located on the radial aspect of the ulnar nerve. It gives rise to a deep palmar branch and continues laterally across the palm as the superficial palmar arch. Venae comitantes of ulnar artery Lymphatic vessels Clinical Relevance Ulnar Canal Syndrome Ulnar canal syndrome refers to compression of the ulnar nerve within the ulnar canal. The most common causes are ganglion cyst, lipoma and trauma. Its clinical features are related to compression of the ulnar nerve and its branches: Sensory – pain and paraesthesia ulnar 1 1/2 digits Motor: Weakness of thumb adduction (adductor pollicis) Weakness of finger abduction and adduction (interossei) Weakness of little finger flexion, abduction and opposition (hypothenar muscles) Initial treatment is usually conservative – analgesia, activity modification, splinting of the wrist. Surgical decompression can be considered in patient who fail conservative measures. By TeachMeSeries Ltd (2025) Fig 2Ulnar canal syndrome can cause pain and paraesthesia in the distribution of the ulnar nerve. Do you think you’re ready? Take the quiz below Pro Feature - Quiz The Ulnar (Guyon’s) Canal Question 1 of 3 Submitting... Skip Next Rate question: You scored 0% Skipped: 0/3 1800 More Questions Available Upgrade to TeachMeAnatomy Pro Challenge yourself with over 1800 multiple-choice questions to reinforce learning Learn More Print Article Rate This Article