Interosseous Membrane of Forearm

Description

The interosseous membrane is composed of 5 ligaments: Central band (key portion to be reconstructed in case of injury), Accessory band- Distal oblique bundle, Proximal oblique cord, and Dorsal oblique accessory cord

Interosseous membrane is a stabilizer of both forearm bones. The radius rotates around ulna during pronosupination

Names

• Interosseous Membrane of Forearm
• Syndesmosis of the forearm
• Middle Radioulnar Joint
• Intermediate Radioulnar Joint

General

• Thin, broad, fibrous membrane that joins the shaft of the ulna and radius
• Attaches to the prominent interosseous borders on the medial radius and lateral ulna
• Divides the forearm into anterior and posterior compartments

Function

• Shifts compressive loads from the distal radius to the proximal ulna
• Reduces wear and tear of individual joints of the upper arm
• Increased tension in supination, relaxed in pronation

Ligamentous Components

• Central band (key portion to be reconstructed in case of injury)
• Accessory band
• Distal oblique bundle
• Proximal oblique cord
• Dorsal oblique accessory cord

Vascular Relationships

• Oval aperture distally conducts the anterior interosseous artery from the anterior forearm to the posterior forearm
• The posterior interosseous artery passes through a gap between the proximal border and oblique cord

Muscle Attachments

• Anterior
  • Flexor pollicis longus
  • Flexor digitorum profundus
  • Pronator quadratus
• Posterior
  • Supinator
  • Abductor pollicis longus
  • Extensor pollicis brevis
  • Extensor pollicis longus
  • Extensor indicis

Interosseous Bursa of Forearm

• Not well defined in the anatomy literature
• Located between the membrane and overlying muscles

---

Clinical Significance

• Acute Compartment Syndrome
• Chronic Exertional Compartment Syndrome
• Radius Ulna Fracture

---

See Also

• Forearm Pain Main
• Physical Exam Forearm
• Forearm Anatomy Main

---