Olecranon

The olecranon is a large bony prominence present at the proximal end of the ulna. Itis palpable overat the posterior surfaceaspect of the elbow. 

Summary

• location:
  • proximal end of the ulna.
  • articulates with the humerus with the olecranon fossa on the posterior surface of the humerus
• blood supply:: arterial supply arises via a
  • ​deep nutrient vessel arising frombranch of the ulnar artery
• relations: is closely associated with
  • posteriorly the olecranon bursa over the posterior surface,
  • anteriorly the semilunar notch over the anterior surface and forms attachment sites for the
  • attachments
    • triceps brachii muscle attached over the superior surface and the
    • posterior and oblique bands of the ulnar collateral ligament and the
    • ulnar part of the flexor carpi ulnaris muscle

Gross anatomy

Location

The olecranon has a beak like-like structure and is bent forwards into the olecranon fossa of the humerus during extension of the elbow. It is present over the posterior surface of the elbow and forms the palpable 'point' of the elbow during its full extension of the elbow. 

Articulations

The olecranon articulates with the humerus via the olecranon fossa on the humerus, which is situated over the posterior surface of the humerus.  

It is continuous with the coronoid process of the ulna via the trochlear or semilunar notch anteriorly. This forms the attachment site for the humerus over the ulnar surface. 

Relations

• olecranon bursa is situated posterior to the olecranon, in between the joint capsule and the tendon of the triceps brachii muscle
• the radial notch of the ulna articulates with the radius, located over the lateral surface of the olecranon
• anteriorly, the elbow joint capsule is attached to the olecranon surface
• ulnar collateral ligament and the flexor carpi ulnaris muscle attach to the medial surface
• distally, it attaches to the flexor digitorum profundus muscle
• laterally, it attaches to the anconeus muscle
• the ulnar nerve passes in between the olecranon and the medial epicondyle of the humerus ¹.  

Blood Supplysupply

The blood supply of the olecranon comes from a deep nutrient branch of the ulnar artery ².

Innervation

The nerve supply of the olecranon comes from the radial nerve and ulnar nerve ³.

History and etymology

The term olecranon originates from the Greek words olene meaning elbow and kranon meaning head.

Related Pathology

• olecranon fracture
• olecranon bursitis
• gout of the olecranon bursa