Radial head

Radial Head

The radial head is an important anatomical structure located at the proximal end of the radius, one of the two bones in the forearm. It plays a crucial role in the function of the elbow joint and forearm, allowing for a wide range of motion including flexion, extension, pronation, and supination.

Anatomy

The radial head is the disc-shaped, proximal end of the radius. It articulates with the capitulum of the humerus and the radial notch of the ulna, forming part of the elbow joint. The radial head is covered with articular cartilage, which facilitates smooth movement within the joint.

Structure

The radial head is cylindrical in shape and slightly concave on its superior surface, which articulates with the capitulum of the humerus. The circumference of the radial head is smooth and articulates with the radial notch of the ulna, forming the proximal radioulnar joint.

Ligaments

The radial head is stabilized by several ligaments:

• The annular ligament encircles the radial head and holds it in place against the ulna.
• The radial collateral ligament provides lateral stability to the elbow joint.

Function

The radial head is essential for the rotational movements of the forearm. It allows the radius to rotate around the ulna, enabling pronation and supination. This movement is critical for various daily activities, such as turning a doorknob or using a screwdriver.

Clinical Significance

Fractures

Radial head fractures are common injuries, often resulting from a fall on an outstretched hand. These fractures can lead to pain, swelling, and limited range of motion in the elbow. Treatment may involve immobilization, physical therapy, or surgical intervention, depending on the severity of the fracture.

Dislocations

Dislocation of the radial head can occur, often in conjunction with elbow dislocations or fractures. Prompt reduction and stabilization are necessary to restore function and prevent long-term complications.

Surgical Considerations

In cases of severe fracture or chronic instability, surgical options such as radial head resection or replacement may be considered. These procedures aim to restore joint function and alleviate pain.

Also see

• Radius (bone)
• Ulna
• Elbow joint
• Pronation and supination
• Annular ligament