eMedicine Specialties > Emergency Medicine > Trauma & Orthopedics

Sternoclavicular Joint Injury

Author: John P Rudzinski, MD, FACEP, Clinical Professor of Surgery and Internal Medicine, University of Illinois College of Medicine, Rockford; Vice Chairman, Department of Emergency Medicine, Rockford Memorial Hospital
Contributor Information and Disclosures

Updated: Jul 7, 2009

Introduction

Background

A freely moveable synovial joint links the upper extremity to the torso, with the sternoclavicular joint (SCJ) participating in all movements of the upper extremity. The SCJ is a saddle-type joint that provides free movement of the clavicle in nearly all planes. The ability to thrust the arm and shoulder forward requires sound function of the SCJ. Because only about 50% of the medial end of the clavicle articulates with the manubrium, the SCJ has little inherent stability. Most of the SCJ's strength and stability originates from the joint capsule and supporting ligaments. The capsule surrounding the joint is weakest inferiorly, while it is reinforced on the superior, anterior, and posterior aspects by the various ligaments. These include the interclavicular, anterior and posterior sternoclavicular, and costoclavicular ligaments.

Pathophysiology

Usually only through the application of significant force do the ligaments supporting the SCJ become completely disrupted, enabling dislocation of the joint. Whether the SCJ subluxes or dislocates depends on the extent of the damage to the supporting ligaments and capsule. Sternoclavicular joint injuries (SJIs) are graded into 3 types.

• A first-degree injury, or simple sprain, constitutes an incomplete tear or stretching of the sternoclavicular and costoclavicular ligaments. Discomfort is mild, and no instability is present. This is the most common type of SJI.
• With a second-degree injury, the clavicle undergoes an anterior or posterior subluxation from its manubrial attachment, signifying a complete breach of the sternoclavicular ligament but at most, only a partial tear of the costoclavicular ligament.
• With a third-degree injury, complete rupture of the sternoclavicular and costoclavicular ligaments permits the clavicle to completely dislocate from the manubrium.

A significant direct or indirect force to the shoulder region can cause a traumatic dislocation of the SCJ.¹ Anterior dislocations of the SCJ are much more common (by a 9:1 ratio), usually resulting from an indirect mechanism such as a blow to the anterior shoulder that rotates the shoulder backward and transmits the stress to the joint. Traumatic contact driving the shoulder forward can cause posterior dislocations of the SCJ, as can direct impact to the superior sternal or medial clavicular surfaces.

Frequency

United States

The ligaments and capsule of the SCJ contribute enough stability to make this one of the least dislocated joints in the body. Sternoclavicular dislocations are uncommon, accounting for only 3% of a series of 1603 shoulder girdle injuries. Posterior dislocations are considerably less common than anterior dislocations. Only 1 patient in the cited series of 1603 shoulder girdle injuries had a posterior dislocation.

Mortality/Morbidity

Mortality and significant morbidity occur infrequently with anterior dislocations of the SCJ. Problems are usually related to issues of physical appearance as well as pain and functional limitations for persons with an active lifestyle.

However, a posterior SCJ dislocation has an estimated 25% complication rate. Complications from posterior displacement of the clavicle have included pneumothorax, laceration of the superior vena cava, occlusion of the subclavian artery or vein, and disruption of the trachea. These and other complications can cause significant disability and even death.²

Sex

Overall incidence of sternoclavicular joint injury is higher in males than in females, probably because of the activities (eg, motor vehicle crash, contact sports) associated with the injury. However, recurrent atraumatic anterior subluxation of the SCJ (usually associated with overall joint laxity) though rare, occurs more frequently in young girls.

Age

Incidence is increased in young adult males, since this population is engaged more often in activities associated with SJI, such as motor vehicle crashes and contact sports.

Clinical

History

• Determine the onset of pain and the mechanism of injury.
  • Sternoclavicular joint (SCJ) dislocations may follow direct trauma to the anteromedial aspect of the clavicle that drives it backward and causes a posterior dislocation.
  • More commonly, dislocations arise from an indirect force applied to the anterolateral or posterolateral shoulder that compresses the clavicle down toward the sternum. The direction the shoulder is driven determines the type of dislocation. When overwhelming compression propels the shoulder forward, the force directed toward the clavicle produces a posterior dislocation of the sternoclavicular joint. If the shoulder is pressed and rotated backward, the force directed down the clavicle produces an anterior dislocation of the sternoclavicular joint.

• Atraumatic SCJ dislocations can occur rarely.
• Patients commonly complain of chest and shoulder pain exacerbated by arm movement or by assuming a supine position.³
• Pain tends to be more severe with posterior dislocations.
• Additional symptoms may be caused by associated injuries or by compression of adjacent structures by a posterior SCJ dislocation and may include the following:
  • Dyspnea
  • Dysphagia
  • Paresthesias

Physical

• Patients typically present with their head tilted toward the affected side, and hold the affected arm across the trunk with the uninjured arm.
• Check vital signs, especially respirations.
  • Tachypnea, stridor, and other signs of respiratory distress (posterior dislocations) may be present.
  • Verify adequacy of circulation. Venous congestion of the head, neck, and/or affected arm may result from posterior dislocations.
• The affected shoulder usually appears shortened and thrust forward.
  • Generally, edema and tenderness are present over the SCJ.
  • Pain manifests with any range of motion testing that affects the SCJ and becomes more severe when a lateral compressive force is applied to the shoulders.
• When viewed from the level of the patient's knees, anterior SCJ dislocations demonstrate a conspicuous asymmetry, with the medial aspect of the affected clavicle appearing prominent. Palpation reveals a medial protrusion.
• Physical findings at the SCJ may be more subtle with posterior SCJ dislocations, with swelling and a defect evident on inspection and palpation.⁴
  • The corner of the sternum on the affected side may be palpated more readily than on the noninjured side.
  • Palpation often reveals exquisite tenderness medially.
  • Soft tissue swelling may obscure any defect and create the false impression of an anterior dislocation.

Causes

• Motor vehicle crashes are the most common mechanism producing sternoclavicular dislocation.
• Athletic injury
  • In a "pile-on" in football, the shoulder off the ground may be rolled backward, causing an anterior dislocation, or rolled forward, causing a posterior dislocation.
  • During a sporting event, an athlete lying on his or her back may be jumped on with the knee of the jumper landing directly on the medial end of the clavicle. A kick delivered to the front of the medial clavicle can also produce dislocation.
• Falls (eg, a person falling on an outstretched abducted arm, driving the shoulder medially)
• Dislocations of the sternoclavicular joint also may result from congenital, degenerative, and inflammatory processes.
• Ligamentous laxity, more common in young girls, is associated with recurrent atraumatic anterior dislocations of the sternoclavicular joint. This tends to be a self-limited condition.

• Search for CME/CE on This Topic »