Olecranon | pacs

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The olecranon is a large bony prominence at the proximal end of the ulna. It is palpable at the posterior aspect of the elbow.

Summary

location
- proximal end of the ulna
- articulates with the olecranon fossa of the humerus
blood supply
- deep nutrient branch of the ulnar artery
relations
- posteriorly the olecranon bursa
- anteriorly the semilunar notch
- attachments
  - triceps brachii muscle attached over the superior surface
  - posterior and oblique bands of the ulnar collateral ligament
  - ulnar part of the flexor carpi ulnaris muscle

Gross anatomy

Location

The olecranon has a beak-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.

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