Introduction
  • Description
    • injury to the distal physis of the clavicle in skeletally immature patients
    • most can be treated nonoperatively with sling immobilization 
  • Epidemiology
    • rare injury, accounting for only 5%-10% of clavicle fractures in children
  • Pathophysiology
    • mechanism
      • fall onto an outstretched extremity or onto side of the shoulder.
      • direct blow
      • child abuse (rare cause)
    • pathoanatomy
      • considered a childhood equivalent to adult AC separation
      • periosteum usually remains intact with injury
      • clavicle displaces away from physis and periosteal sleeve, both of which remain attached to the AC and CC ligaments 
Anatomy
  • Clavicle osteology
    • S-shaped bone
    • medial clavicle is connected to the axial skeleton via the sternoclavicular joint
    • lateral clavicle is connected to the scapula via the acromioclavicular joint
  • Clavicle ossification
    • overview
      • first bone to ossify in the fifth week in utero
      • physes are the last to close
    • central clavicle
      • initial growth via intramembranous ossification from the ossification center in the central portion of the clavicle (<5 years)
    • distal clavicle
      • continued growth via secondary ossification at lateral physis
      • lateral epiphysis does not ossify until age 18 years
    • medial clavicle
      • approximately 80% of clavicular growth occurs at the medial physis (secondary ossification)
      • medial epiphysis does not begin to ossify until 18 to 20 years
      • last physis to close in body (20-25yrs)
        • thus sternoclavicular dislocations in teenagers/young adults are usually physeal fracture-dislocations
  • Coracoclavicular (CC) ligaments provide vertical stability
    • trapezoid ligaments
      • 2 cm from AC joint
    • conoid ligaments
      • 4 cm from AC joint
  • Acromioclavicular (AC) ligaments provide horizontal stability
Classification
 
 Classification
Type I Sprain of the AC ligaments, periosteal tube intact  
Type II Partial disruption of the periosteal tube
Type III Large split in the periosteal tube with superior displacement
Type IV
Large split in the periosteal tube with posterior displacement of the lateral clavicle through trapezius
Type V Complete disruption of the periosteal tube with displacement through the deltoid and trapezius   
Type VI Inferior dislocation of the distal clavicle below the coracoid   
 
Presentation
  • Symptoms 
    • pain
    • ecchymosis in older children
  • Physical exam
    • tenderness and deformity at the distal clavicle
    • skin tenting may be present
    • pseudo-paralysis of the affected ipsilateral extremity may be present in newborns 
      • reflexes remain intact following isolated clavicle fractures
        • can help differentiate from brachial plexus injuries
Imaging
  • Radiographs
    • initial views
      • AP +/- Zanca (for intra-articular injury) 
      • axillary lateral to define a Type-IV injury
    • later findings
      • intact periosteal sleeve forms a "new" lateral clavicle inferior to the superiorly displaced medial fragment.
Treatment
  • Nonoperative 
    • sling management 
      • indications
        • indicated in most cases, especially if periosteum is intact 
          • a new clavicle will form within the intact periosteal sleeve resulting in a Y shaped clavicle
          • the displaced clavicle will typically reabsorb with time and growth 
  • Operative
    • surgical reduction
      • absolute indications (rare)
        • open fractures
        • significant skin compromise
        • displaced intra-articular extension
        • a/w neurovascular injuries requiring surgery
      • relative
        • severely displaced fractures in older patients with nearly closed physis
        • displaced and entrapped fragment in trapezius
        • floating shoulder injuries
        • some Type III fractures in patients approaching skeletal maturity
        • types IV, V, and VI may need open reduction with repair of periosteal sleeve
Complications
  • Laceration of subclavian artery or vein
    • rare
    • suggested by rapidly expanding hematoma
    • thick periosteum usually protective
    • treatment = vascular repair
  • Nonunion
    • rare
    • seen after attempts at open reduction
    • treatment = surgical fixation with iliac crest bone grafting
  • Pin migration
    • pin fixation around the clavicle should be avoided