Elbow joint – Anatomy Atlas

Elbow joint (medial/lateral views)

The elbow joint is made up of three joints including the humeroulnar, humeroradial and proximal radioulnar joints. The humeroulnar joint is the joint between the trochlea on the medial aspect of the distal end of the humerus and the trochlear notch on the proximal ulna. The humeroradial joint is formed between the capitulum on the lateral aspect of the distal end of the humerus with the head of the radius. The proximal ends of the radius and ulna articulate with each other at the proximal radioulnar joint. There are four main ligaments that support the elbow joint: the ulnar collateral ligament, radial collateral ligament, annular ligament, and quadrate ligament. The medial and lateral collateral ligaments are made up of three smaller ligamentous parts: the medial collateral ligament is composed of the anterior oblique ligament, posterior oblique ligament, and the transverse ligament (Cooper’s ligament). The parts that comprise the lateral collateral ligament are the annular ligament, the lateral radial collateral ligament, and the lateral ulnar collateral ligament.

Elbow joint (sagittal section)

The elbow joint is enveloped in a joint capsule and lined with a synovial membrane. These two structures are separated from each other by fat pads that are located superficial to the primary areas of stress to the joint (olecranon, coronoid fossa and radial fossa). During movements (flexion and extension), the fat pads are pulled away by the tendinous attachments of the brachialis and triceps brachii muscles to allow space for bony processes. Extension of the elbow is facilitated by the olecranon bursa which serves as a lubricating component between the olecranon of the ulna and the distal tendon of the triceps brachii muscle.