Supporting Structures

Question 1

Describe the capsule of the elbow joint

Answer 1

> strong and fibrous
encompasses all three joints (humero-ulnar, humero-radial, radio-ulnar)
attaches to edges of all articular surfaces incl. radio-ulnar

Question 2

Describe the ligaments of the elbow joint

Answer 2

> Ulnar collateral ligament (medial)

• thick triangular band fanning out from medial epicondyle t medial aspects of olecranon and coronoid process (anterior, posterior and intermediate bands)
• Prevents valgus strain

> Radial Collateral ligament (lateral)
- single, triangular band from lateral epicondyle to annular ligament
- Prevents varus strain
(+ lateral ulnar collateral ligament - lateral epicondyle to supinator crest)
(+ accessory collateral ligament - annular ligament to supinator crest)

Question 3

Describe the ligaments of the superior radio-ulnar joint

Answer 3

> Annular ligament

• Posterior to anterior margin of radial notch - holds radial head in place
• inferior diameter = smaller
• inner aspect has fibrocartilaginous cells for articulation with humerus

> Quadrate ligament

• small ligament from inferior border of radial notch to neck of radius
• laxity allows full range of pronation/supination

Question 4

Describe the interosseous membrane

Answer 4

• Fibrous syndesmosis
• 2 layers running in opposite directions
• hiatus’ for neurovascular bundles
• stabilises radius and ulna

Question 5

describe the capsule and ligaments of the inferior radio-ulnar joint

Answer 5

> Fibrous capsule around articular margins
anterior and posterior ligaments
triangular fibrocartilaginous ligament
- holds radius and ulna together
- from lateral ulna styloid process to inferior aspect of ulnar notch
- separates inferior radio-ulnar joint from wrist joint