Elbow Joint Anatomy

Elbow Joint

• Upper surface of head of radius articulates with capitulum and trochlear notch of ulna, which articulates with trochlea of humerus.
• Elbow joint articulates with superior radioulnar joint.

Elbow Joint Structure

• Has a capsule enclosing the joint, which is strong and fibrous, strengthening the joint.
• Joint capsule is thickened medially and laterally to form collateral ligaments, stabilizing flexing and extending motion of the arm.

Bursae

• Intratendinous olecranon: located within the tendon of the triceps brachii.
• Subtendinous olecranon: between the olecranon and the tendon of the triceps brachii, reducing friction during extension and flexion of the arm.
• Subcutaneous olecranon bursa: between the olecranon and the overlying connective tissue, implicated in olecranon bursitis.

Ligaments

• Ulnar collateral ligament (medial): originates from the medial epicondyle and attaches to the coronoid process and olecranon of the ulna.
• Radial collateral ligament (lateral): found on the lateral side of the joint, extending from the lateral epicondyle and blending with the annular ligament of the radius.
• Annular ligament: a ligament from the proximal radioulnar joint.

Blood Supply

• From anastomosis around the elbow joint, formed by branches of the brachial artery.

Nerve Supply

• Branches from:
  • Ulnar nerve.
  • Median nerve.
  • Radial nerve.
  • Musculocutaneous nerve.

Movements

• Flexion: by anterior compartment muscles (brachialis, biceps brachii, brachioradialis).
• Extension: by posterior compartment muscles.

Clinical Applications

• Venipuncture: cubital fossa is a common site for sampling and transfusion of blood, and intravenous injections.
• Blood pressure measurements: cubital fossa is a site for placement of the diaphragm of the stethoscope.

Supracondylar Fracture

• A fracture of the distal humerus, typically transverse or oblique, common in children than adults.
• Can cause Volkmann’s ischaemic contracture if not repaired.

Elbow Anatomy

• Elbow joint is a hinge-type synovial joint connecting the upper arm to the forearm.
• Composed of 3 bones, 2 joints, one capsule, and is a hinge joint.

Clinical Relevance: Injuries to the Elbow Joint

• Bursitis:
  • Subcutaneous bursitis: caused by repeated friction and pressure, can become infected.
  • Subtendinous bursitis: caused by repeated flexion and extension of the forearm.
• Dislocation:
  • Usually occurs when a young child falls on a hand with the elbow flexed.
  • Distal end of the humerus is driven through the weakest part of the joint capsule, usually tearing the ulnar collateral ligament.
• Epicondylitis (Tennis elbow or Golfer’s elbow):
  • Overuse strain of the common tendon, causing pain and inflammation around the affected epicondyle.
  • Tennis players experience pain in the lateral epicondyle, while golfers experience pain in the medial epicondyle.