Sternoclavicular joint

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Sternoclavicular articulation. Anterior view.

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Carnegie stage
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Precursor
Gives rise to
Part of

The sternoclavicular joint (SC joint) is a synovial joint between the sternum and the clavicle. It is one of the four joints that compose the shoulder complex, which also includes the acromioclavicular joint, the glenohumeral joint, and the scapulothoracic joint.

Anatomy

The sternoclavicular joint is a saddle joint but functions as a ball-and-socket joint due to the presence of an articular disc. The joint is formed by the articulation of the medial end of the clavicle with the manubrium of the sternum and the first costal cartilage.

Ligaments

The stability of the sternoclavicular joint is maintained by several ligaments:

• The anterior sternoclavicular ligament and posterior sternoclavicular ligament reinforce the joint capsule.
• The interclavicular ligament connects the two clavicles across the top of the sternum.
• The costoclavicular ligament anchors the clavicle to the first rib.

Muscles

Several muscles contribute to the movement and stability of the sternoclavicular joint, including:

• The sternocleidomastoid muscle
• The subclavius muscle
• The pectoralis major muscle

Function

The sternoclavicular joint allows for a wide range of movements, including:

• Elevation and depression of the clavicle
• Protraction and retraction of the clavicle
• Rotation of the clavicle around its longitudinal axis

These movements are essential for the full range of motion of the shoulder.

Clinical significance

Injuries to the sternoclavicular joint are relatively rare but can occur due to trauma, such as a direct blow to the shoulder or a fall onto an outstretched hand. Conditions affecting the SC joint include:

• Sternoclavicular dislocation
• Osteoarthritis
• Rheumatoid arthritis

Imaging

The sternoclavicular joint can be evaluated using various imaging techniques, including:

• X-ray
• CT scan
• MRI

See also

• Acromioclavicular joint
• Glenohumeral joint
• Scapulothoracic joint
• Shoulder