Atlas

Elbow

The elbow joint is a complex joint composed of three distinct synovial articulations: the humeroulnar, humeroradial, and proximal radioulnar joints, all enclosed within a single joint capsule. This anatomical structure allows flexion and extension movements of the forearm on the arm, as well as pronation and supination of the forearm.
Joint stability is ensured by a complex ligamentous system that includes the ulnar collateral ligament, the radial collateral ligament, and the annular ligament of the radius.
The articular surfaces are covered with hyaline cartilage, which facilitates movement by reducing friction. The joint is surrounded by important tendinous structures, including the tendons of the lateral and medial epicondyles, which are frequently involved in degenerative conditions and hemophilic arthropathy.

Projections

In musculoskeletal ultrasound, images are acquired through different projections that allow visualization of the elbow structures from various angles.

Anterior

Anterior

The anterior projection allows visualization of the structures located at the front of the elbow, such as the coronoid fossa, the coronoid process of the ulna, and the anterior joint capsule. This view is particularly useful for assessing joint effusions, synovial thickening, and cartilage alterations of the humeral trochlea, which are frequently observed in hemophilic arthropathy.
Lateral

Lateral

The lateral projection focuses on the outer part of the elbow, visualizing the lateral epicondyle, the humeral capitulum, the radial head, and the radial collateral ligament. This perspective is essential for diagnosing lateral epicondylitis, assessing alterations of the radiocapitellar compartment, and detecting joint effusions or synovial thickening in the lateral region of the joint.
Medial

Medial

The medial projection provides a view of the inner part of the elbow, allowing observation of the medial epicondyle, the humeral trochlea, the coronoid process, and the ulnar collateral ligament. This projection is essential for evaluating medial epicondylitis, alterations of the ulnotrochlear compartment, and manifestations of hemophilic arthropathy, which frequently affect this region.
Posterior

Posterior

The posterior projection allows exploration of the structures located behind the joint, including the olecranon, the olecranon fossa, and the olecranon bursa. This view is crucial for identifying olecranon bursitis, posterior osteophytes, and fluid collections that characterize the acute and chronic phases of hemophilic arthropathy.