ellebogen

The elbow, or ellebogen in Dutch, is a complex hinge and pivot joint that connects the upper arm to the forearm. It involves three bones—the distal humerus, the ulna, and the radius—and encompasses three articulations: the humero-ulnar, the humero-radial, and the proximal radioulnar joints. These joints are enclosed by a common synovial capsule and stabilized by ligaments and surrounding muscles.

The distal humerus contains the trochlea and capitulum, which articulate with the ulna and radius, respectively. The ulna forms a hinge with the humerus at the humero-ulnar joint, while the radius participates in the humero-radial articulation and the proximal radioulnar joint, which allows forearm rotation. The interosseous membrane binds the radius and ulna along their lengths.

Movements at the elbow include flexion and extension primarily at the humero-ulnar joint, while pronation and supination occur around the proximal radioulnar joint and adjacent structures. Normal elbow motion enables daily activities, with typical ranges that may vary among individuals.

Stability is provided by ligaments, including the medial ulnar collateral ligament (with anterior, posterior, and transverse bands) and the lateral radial collateral ligament, along with the annular ligament that encircles the head of the radius. The joint is supported by surrounding muscles, plus the capsule and surrounding fascia. The brachial artery supplies blood, with the radial and ulnar arteries as branches; innervation comes from the median, radial, and ulnar nerves.

Common clinical issues include olecranon fractures, elbow dislocations, tennis elbow (lateral epicondylitis), golfer’s elbow (medial epicondylitis), arthritis, and nerve entrapments such as cubital tunnel syndrome. Imaging and clinical assessment guide management.