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Definition
By: Gregory R. Waryasz, MD
The sternoclavicular joint of the musculoskeletal system is characterized by connecting the upper extremity to the chest.
It is part of the upper extremity and consists of bone, skeletal muscle, cartilage, synovial tissue, and tendon.
Its unique structural is that it is a saddle type joint that functions as a ball and socket with synovial tissue. The joint is covered by a capsule.
The bones are the clavicle and manubrium/sternum. The articulation surface of the clavicle is larger than the sternum. Both are covered with fibrocartilage.
There is an articular disc located between the articulation surfaces.
The ligaments are the anterior and posterior sternoclavicular ligaments, interclavicular ligament, and costoclavicular ligament.
The blood supply is from the internal thoracic and the suprascapular arteries.
The innervation is from the medial supraclavicular nerve and the nerve to the subclavius.
The sternoclavicular joint’s components as well as all other bones, muscles, and ligaments of the body are derived of mesodermal origin in the embryo.
The function of the sternoclavicular joint is to be the only true articulation between the upper extremity and the axial skeleton. The articular disc helps to absorb transmitted forces from the clavicle to the sternum.
The pectoral girdle and upper limb are able to move due to the sternoclavicular joint.
With full elevation of the limb, the sternoclavicular joint allows the clavicle to be raised to about 60 degrees. The sternoclavicular joint can be moved anteriorly or posteriorly over a range of between 25 to 30 degrees.
Common diseases of the sternoclavicular joint include arthritis, fractures, and dislocation.
Fractures can occur with the claviclethat result in a change to the biomechanics of the sternoclavicular joint.
Arthritis is a condition of joint space narrowing leading to pain.
Dislocation is not common, but can occur either anteriorly or posteriorly. The anterior dislocation is more common.
Commonly used diagnostic procedures include clinical history, physical exam, x-ray, CT, and MRI.
It is usually treated with rest, NSAIDs, physical therapy, and possibly surgery. Dislocation and fractures may not respond to closed reduction and may require surgery. Arthritis can be treated with NSAIDs and physical therapy, but may require surgery to restore scapular movement.
References
Davis MF, Davis PF, Ross DS. Expert Guide to Sports Medicine. ACP Series, 2005.
Elstrom J, Virkus W, Pankovich (eds), Handbook of Fractures (3rd edition), McGraw Hill, New York, NY, 2006.
Koval K, Zuckerman J (eds), Handbook of Fractures (3rd edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Lieberman J (ed), AAOS Comprehensive Orthopaedic Review, American Academy of Orthopaedic Surgeons, 2008.
Moore K, Dalley A (eds), Clinically Oriented Anatomy (5th edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Wheeless’ Textbook of Orthopaedics: Sternoclavicular Joint Injury (http://www.wheelessonline.com/ortho/sternoclavicular_joint_injury)