Sternoclavicular Joint Injury

Basics

Description

  • Sternoclavicular joint (SCJ) is the only joint that connects the upper limb to the trunk
  • Among the least frequently injured joints in the body
  • Most commonly due to athletic or vehicular injuries
  • Congenital or spontaneous dislocation and subluxation are rarely seen
  • SCJ stability depends on ligamentous attachments, primarily anterior and posterior sternoclavicular ligaments, interclavicular ligament, and costoclavicular ligament
  • Diagnosis of injury or dislocation requires a high suspicion

Etiology

  • Injury to the SCJ can be from sprains, subluxations, or dislocations of the ligamentous structure
  • In sprains, ligamentous capsule remains intact
  • Subluxation occurs when sternoclavicular ligament ruptures while costoclavicular ligament remains intact
  • Complete ligamentous disruption leads to dislocation
  • The SCJ can dislocate anteriorly or posteriorly. A large force is required. A greater force is required to displace the clavicle posteriorly
  • Dislocations may be more common in patients with hypermobility syndromes such as Ehlers–Danlos syndrome
  • Direction of dislocation depends on the shoulder position:
    • Anterior dislocation more likely when the acromion is posterior to the manubrium
    • Posterior dislocation more likely when the acromion is anterior to the manubrium
  • Anterior dislocation is more common (more than 90% of dislocations):
    • Caused by a posteriorly directed force to the anterolateral aspect of the shoulder
    • Reciprocal anterior displacement of the medial clavicle
    • May be associated with pneumothorax, hemothorax, pulmonary contusion, or rib fractures
    • Subluxation and dislocation may occur spontaneously
  • Posterior SCJ dislocation results from:
    • Anterior-to-posterior blow to the medial clavicle
    • Anteriorly directed force to the lateral aspect of the ipsilateral shoulder
    • A blow to the contralateral shoulder when the injured side is braced against an immobile object
  • Posterior dislocation is a surgical emergency:
    • Indications for immediate reduction:
      • Compression or tear of trachea, esophagus, or great vessels
      • Recurrent laryngeal nerve injury

Pediatric Considerations
  • The medial epiphyseal growth plates of the clavicles are last to ossify, and fuse between ages 22 and 25:
    • Until fusion, growth plate is the weakest part of the joint
  • Fractures through the medial epiphysis mimic SCJ dislocations:
    • Most commonly Salter–Harris type I or II fractures
    • True dislocations of the SCJ are extremely rare in children because of strong ligamentous attachments

There's more to see -- the rest of this topic is available only to subscribers.