Your elbow’s a joint formed where three bones come together -- your upper arm bone, called the humerus, and the ulna and the radius, the two bones that make up your forearm.
Each bone has cartilage on the end, which helps them slide against each other and absorb shocks. They’re lashed into place with tough tissues called ligaments. And your tendons connect your bones to muscles to allow you to move your arm in different ways.
Like all synovial joints, the elbow joint has a capsule enclosing the joint. This in itself is strong and fibrous, strengthening the joint. The joint capsule is thickened medially and laterally to form collateral ligaments, which stabilise the flexing and extending motion of the arm.
A bursa is a membranous sac filled with synovial fluid. It acts as a cushion to reduce friction between the moving parts of a joint, limiting degenerative damage. There are many bursae in the elbow, but only a few have clinical importance:
Intratendinous – located within the tendon of the triceps brachii.
Subtendinous – between the olecranon and the tendon of the triceps brachii, reducing friction between the two structures during extension and flexion of the arm.
Subcutaneous (olecranon) bursa – between the olecranon and the overlying connective tissue (implicated in olecranon bursitis).
The joint capsule of the elbow is strengthened by ligaments medially and laterally.
The radial collateral ligament is found on the lateral side of the joint, extending from the lateral epicondyle, and blending with the annular ligament of the radius (a ligament from the proximal radioulnar joint).
The ulnar collateral ligament originates from the medial epicondyle, and attaches to the coronoid process and olecranon of the ulna.
Nerve supply is provided by the median, musculocutaneous and radial nerves anteriorly, and the ulnar nerve posteriorly. Numbness and tingling in the hand and fingers are common symptoms of nerve compression.