SC Dislocation

Aka: SC Dislocation, Sternoclavicular Dislocation, Sternoclavicular Joint Dislocation, SC Separation, Sternoclavicular Separation, Sternoclavicular Joint Subluxation

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II. Epidemiology

  1. Uncommon injury (<1% of all dislocations)

III. Anatomy

  1. Four ligaments (in addition to a saddle-like structure) stabilize the sternoclavicular joint
    1. Anterior sternoclavicular ligament
    2. Posterior sternoclavicular ligament
    3. Interclavicular ligament
    4. Costoclavicular ligament

IV. Precautions

  1. Sternoclavicular Dislocations are associated with serious neck and chest injuries due to high force injuries
    1. Posterior Sternoclavicular Dislocations are life threatening in up to 30% of cases due to compression
    2. See Associated Conditions below

V. Mechanism

  1. High impact direct blow to chest (e.g. MVA)
    1. Results in posterior Sternoclavicular Dislocation
  2. Fall onto lateral Shoulder with compression force directed medially
    1. Causes either anterior (most common) or posterior Sternoclavicular Dislocation

VI. Grading

  1. Grade 1: Sternoclavicular Sprain
  2. Grade 2: Sternoclavicular Subluxation
  3. Grade 3: Sternoclavicular Dislocation

VII. Types: Sternoclavicular Dislocation

  1. SC Joint Subluxation
    1. Partial ligamentous tear
  2. Anterior Dislocation (More common than posterior dislocation)
    1. Routine oupatient management
    2. May occasionally occur spontaneously without Trauma
      1. Older adult presents with painless sternal mass
      2. Affects sternal end of clavicle
  3. Posterior Dislocation (uncommon, 10% of SC Dislocations)
    1. Requires emergent Consultation for reduction
    2. High risk for underlying structure (Great Vessel, trachea, esophagus) injury (30% of cases)
      1. Leads to Dyspnea and vascular compression
      2. Mortality is as high as 3-4%

VIII. Differential Diagnosis

  1. Clavicle Epiphyseal Fracture (Salter Harris Fracture) in child
    1. Medial clavicular physis is the last Growth Plate to fuse (>age 20 years)
    2. Non-surgical management as with SC Dislocation

IX. Exam

  1. See Primary Survey
  2. See Secondary Survey
  3. Airway exam
    1. Evaluate for airway compromise (including Stridor, tracheal injury)
  4. Respiratory Exam
    1. Evaluate for other Chest Injury (including Pneumothorax, Lung Contusion)
  5. Cardiovascular examination
    1. Evaluate for vascular compromise including radial pulses
  6. Gastrointestinal Exam
    1. Evaluate for esophageal injury or compression
  7. Neurologic Exam
    1. See Hand Neurovascular Exam
    2. Evaluate for Brachial Plexus Injury

X. Findings: Symptoms and Signs

  1. SC Joint Subluxation
    1. Pain and tenderness at the SC Joint
    2. However, visible deformity or prominence to the joint is uncommon
    3. Partial SC ligamentous tears
      1. In contrast, SC Dislocations are complete ligamentous tears
      2. Complete tears (dislocations) require significant force mechanism (e.g.MVA, sports collision)
  2. Anterior Sternoclavicular Dislocation (more common than posterior dislocations)
    1. Pain, tenderness and prominence at sternoclavicular Joint
    2. Sternoclavicular pain with any Shoulder Range of Motion
  3. Posterior Sternoclavicular Dislocation
    1. May be occult injury or divit seen at SC joint
    2. Underlying mediastinal injury may present in various ways
      1. Stridor, Dyspnea or hoarse voice (tracheal injury or compression)
      2. Neurologic deficits (Brachial Plexus Injury)
      3. Vascular deficits (Great Vessel injury)
      4. Dysphagia (esophageal injury)

XI. Associated Conditions

  1. Anterior Sternoclavicular Dislocations
    1. Pneumothorax
    2. Hemothorax
    3. Rib Fracture
    4. Pulmonary Contusion
  2. Posterior Sternoclavicular Dislocations
    1. Subclavian Vein Injury
    2. Brachial Plexus Injury
    3. Pneumothorax
    4. Esophageal Injury
    5. Tracheal Injury
    6. Cardiac Dysrhythmia

XII. Imaging

  1. Anterior Sternoclavicular Dislocation
    1. Sternoclavicular XRay
      1. SC Joint difficult to visualize on XRay
      2. View angled upward including uninjured side helpful (see Serendipity View as below)
    2. Sternoclavicular joint MRI may be necessary
      1. Physeal Fracture of medial clavicle may also occur and may be occult
        1. Clavicle physis is last in the body to fuse (age 23-25 years)
  2. Posterior Sternoclavicular Dislocation
    1. Chest XRay
      1. Often normal
      2. May demonstrate associated chest injuries (e.g. Pneumothorax, Hemothorax)
    2. Serendipity View XRay (oblique view of SC)
      1. Patient lies supine on bed
      2. Xray angled 40 degrees toward manubrium
      3. Allows for visualization of both sternoclavicular joints
      4. Dislocated clavicle appears inferior compared with the unaffected side
    3. CT Chest with contrast angiography (CTA)
      1. Definitive and preferred imaging modality
      2. Also evaluates neurovascular structures and mediastinal impingement
      3. MRI may be performed as alternative, but rarely done in acute evaluations
    4. Bedside Ultrasound (linear probe)
      1. Measure distance between clavicle and Sternum (and compare to unaffected side)
      2. Bengtzen (2017) J Emerg Med 52(4): 532-5 +PMID:28087089 [PubMed]

XIII. Management: Anterior Sternoclavicular Dislocation

  1. General measures
    1. Grade 1 and 2 anterior dislocations tend to be stable without significant morbidity
    2. Analgesics
      1. Expect pain resolution at 2-3 weeks after injury
    3. Immobilization with sling, figure of eight splint or velpeau bandage
    4. Orthopedic Consultation
    5. Return to activity
      1. Full Physical Activity is typically by 3 months after injury
  2. Reduction by traction and manipulation (Grade 3 dislocations)
    1. May be performed in first 7-10 days after injury
    2. Technique (under Procedural Sedation)
      1. Patient supine with towel roll between Scapulae
      2. Ipsilateral arm abducted to 90 degrees and extended 15 degrees
      3. Inline traction applied by an assistant
      4. Apply anterior to posterior pressure to medial clavicle as needed
    3. Reduction difficult to maintain and commonly recurs (50% re-dislocate)
    4. No loss of function (cosmetic only)
  3. Surgery (uncommonly indicated beyond reduction, Grade 3 dislocations)
    1. Indicated for post-Traumatic Arthritis
    2. Excise medial 1 to 2 cm of clavicle

XIV. Management: Posterior Sternoclavicular Dislocation

  1. Emergent Consultation
    1. Orthopedics
    2. Cardiothoracic surgery
  2. Emergent reduction technique
    1. Indications
      1. Airway compression (e.g. Stridor)
      2. Pulseless extremity and orthopedics not immediately available
    2. Perform under Procedural Sedation
    3. Shoulder extension
      1. Patient supine with towel roll between Scapulae
      2. Extend and abduct the affected arm while another provider applies counter-traction
        1. See reduction technique under anterior SC Dislocation above
    4. May also attempt to concurrently pull medial clavicle anteriorly
      1. Clavicle may be grasped with pointed instrument (e.g. towel clip applied through sterile skin)
  3. Open reduction by orthopedic surgery indications
    1. Dysphagia
    2. Shortness of Breath
    3. Neurovascular compromise (see Hand Neurovascular Exam)
    4. Decreased peripheral pulses

XV. References

  1. (2012) ATLS, ACOS, Chicago, p.96
  2. Jhun and Roepke in Herbert (2015) EM:Rap 15(11): 10-11
  3. Kiel and Koneru (2019) Crit Dec Emerg Med 33(9): 17-27
  4. Riekena and Huang (2021) Crit Dec Emerg Med 35(3): 12-3

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