Guyon's Canal

Guyon’s canal is a narrow, fibro-osseous tunnel located on the anteromedial aspect of the wrist. It serves as a passageway for the ulnar nerve and ulnar artery as they enter the hand. This canal is clinically significant due to its association with ulnar nerve compression syndromes

Boundaries

Contents

• Ulnar nerve (splits into superficial and deep branches within or just distal to the canal)
• Ulnar artery (accompanies the nerve, also divides into superficial and deep branches)

Zones of Compression

Relations

• Proximal to: Ulnar nerve and artery in the forearm
• Distal to: Superficial palmar arch, digital branches, and motor innervation of intrinsic hand muscles

Function / Significance

• Provides a protected route for ulnar neurovascular structures into the palm
• Divides ulnar nerve into motor and sensory branches

Clinical Significance

• Guyon’s Canal Syndrome: Ulnar nerve compression due to ganglion cysts, repetitive pressure (e.g., cycling), fractures of the pisiform or hamate
  • Motor symptoms: Weak grip, clawing of 4th/5th fingers
  • Sensory symptoms: Numbness/tingling of ulnar 1.5 digits
• Handlebar Palsy: Common in cyclists due to prolonged pressure on hypothenar region
• Distinguishing from Cubital Tunnel Syndrome: Guyon’s canal affects hand only; no forearm muscle involvement

Comparative Anatomy

Guyon’s canal is most prominent in humans due to the increased use of tools and fine motor control. Other species with grasping limbs may have a similar passage but typically without the same clinical relevance.