Carpal Tunnel

Illustration of the carpal tunnel overlying an MRI of the wrist

Illustration of the carpal tunnel

Description

General

• Narrow fibro-osseous passageway found on the anterior portion of the wrist
• Houses many tendons and the median nerve as they pass into the hand

Anatomic Borders

• Radial: Scaphoid tubercle, ridge of Trapezium
• Ulnar: Hook of Hamate, Pisiform
• Floor: Proximal carpal row (as above)
  • Sometimes called deep carpal arch or carpal groove
• Roof: Transverse Carpal Ligament
  • Often called the flexor retinaculum

Contents From Superficial to Deep

• Four tendons of flexor digitorum superficialis
  • Ring, middle finger more superficial to index and little finger
• Median Nerve
  • Found somewhat lateral to midline
• The tendon of flexor pollicis longus (laterally)
• Four tendons of flexor digitorum profundus

Variant Anatomy

• Persistent median artery of the forearm
• Bifid median nerve
• Presence of the motor branch of the median nerve within the carpal tunnel
• Presence of palmaris longus tendon within the carpal tunnel

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Clinical Significance

• Carpal Tunnel Syndrome
• Carpal Tunnel Injection

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See Also

• Wrist Anatomy Main
• Wrist Pain Main
• Physical Exam Wrist

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