Updated: 10/9/2022

Distal Humerus Physeal Separation - Pediatric

Review Topic
  • summary
    • Distal Humerus Physeal Seperations are traumatic fractures usually seen in children under the age of three and are often associated with child abuse. 
    • Diagnosis can be made with plain radiographs of the elbow. 
    • Treatment is usually operative closed reduction and percutaneous pinning
  • Epidemiology
    • Demographics
      • typically seen in children under the age of 3
      • although variations can be seen in older children (see below)
  • Etiology
    • Mechanism
      • vaginal delivery (birth fracture)
        • from force of labor or obstetric maneuvers
          • shoulder dystocia and traumatic delivery are at higher risk
      • cesarean section
        • from excessive traction
      • nonaccidental trauma
        • rotational force / twisting
      • fall on outstretched hand with elbow extended
    • Pathoanatomy
      • physis is biomechanically the weakest location in distal humerus
        • it is also referred to as a transphyseal distal humerus fracture
    • Associated conditions
      • abuse or battered child syndrome (up to 50%)
  • Classification
    • Salter-Harris classification
      • older children (>3y) have Salter-Harris II injuries
        • metaphyseal fragment attached to distal fragment
      • younger children (<3y) have Salter-Harris I injuries
        • pure physeal injury
      • rare cases have intra-articular extension (Salter-Harris III or IV)
        • can be difficult to differentiate from a lateral condyle fracture
    • Displacement of the distal fragment
      • most commonly posteromedial
      • rarely can be anterior
  • Presentation
    • History
      • birthing process (see above)
      • fall from height (bed, chair, down stairs) typically onto extended elbow
      • another child jumps/falls on a child's elbow
      • nonaccidental trauma
        • unwitnessed injuries
        • inconsistent explanations
        • history of multiple injuries, burns, bites, bruising
        • skin lesions are most common findings in nonaccidental trauma
    • Physical exam
      • inspection
        • pseudoparalysis / diminished spontaneous movement
        • swelling or ecchymosis
      • neurovascular
        • rarely neurovascular compromise
  • Imaging
    • Radiographs
      • recommended views
        • AP and lateral centered on the elbow
        • "baby gram"
          • (radiograph of entire extremity) or forearm/arm radiographs can lead to missed diagnosis
        • stress radiographs
          • may be helpful to clarify the diagnosis
        • skeletal survey
          • if child abuse suspected
      • findings
        • posteromedial displacement of the radial and ulnar shafts relative to the distal humerus
          • may be the only finding in infants
        • forearm not aligned with humeral shaft
        • soft tissue swelling, joint effusion (posterior fat pad)
          • anterior fat pad may be absent
        • if capitellar ossification center is present, it will be aligned with radius shaft, making diagnosis definitive
    • Ultrasound
      • indications
        • uncertain diagnosis
      • advantage
        • no need for sedation
      • disadvantage
        • need experiences technician
      • findings
        • static exam
          • detect separation of epiphysis from metaphysis by noting lack of cartilage at distal humeral metaphysis
        • dynamic exam
          • detect instability of epiphysis relative to metaphysis
    • MRI
      • not routinely used
      • disadvantage
        • requires sedation in young children
    • Elbow arthrography
      • indications
        • uncertain diagnosis
        • often combined with CRPP in OR
      • findings
        • visualization of entire distal articular surface and proximal radius
      • technique
        • posterolateral approach or direct posterior approach
          • direct posterior into olecranon fossa recommended in young children to prevent iatrogenic damage to the articular cartilage when posterolateral portal is used
        • inject equal parts saline:contrast
        • bring elbow through range of motion
        • if pinning is needed, arthrogram aids visualization of pin starting points on capitellum
        • aids assessment of quality of reduction by seeing anterior humeral line intersecting capitellum
      • advantage
        • if performed under anesthesia in OR, can perform reduction and stabilization simultaneously if needed
  • Differential
    • Elbow dislocation
      • almost never happens in <3 yrs because distal humerus physis is weaker than bone-ligament interface, predisposing to physeal fracture rather than ligament disruption/dislocation
      • typically distal fragment is displaced posterolaterally with elbow dislocations
    • Other fractures
      • often misdiagnosed (or delayed diagnosis up to 1 week) as supracondylar, condyle, epicondyle fractures
  • Treatment
    • Nonoperative
      • posterior long arm splint then long arm casting x 2-3 weeks
        • indications
          • limited role because most fractures are displaced
          • nondisplaced fractures
          • late presenting fractures
            • treat nonoperatively initially
            • deformity will persist/develop, requiring osteotomy in future
    • Operative
      • closed reduction and pinning
        • indications
          • displaced fractures (most)
            • pinning is necessary to ensure adequate reduction, which may be lost with casting alone once the swelling subsides
        • technique
          • combined with elbow arthrogram to determine direction of initial displacement and adequate reduction
  • Technique
    • Closed Reduction and Pinning
      • approach
        • general anesthesia
        • use elbow arthrogram to determine direction of displacement
      • reduction
        • maneuver
          • gentle traction (very little force required)
            • distal fragment may sometimes be grasped between index finger and thumb and reduced to humeral shaft
          • correction of translation/malrotation
          • elbow flexion
        • acceptable parameters (similar to supracondylar humerus fractures)
          • no cubitus varus
          • anterior humeral line should bisect capitellum
          • no malrotation
      • pinning
        • 2 or 3 x 0.062inch K wires
          • these larger pins help prevent loss of reduction
        • from lateral side, retrograde fashion
        • divergent
        • engage both cortices
        • good spread at fracture site
        • then perform live fluoroscopy through range of motion and slight varus/valgus stress to ensure no loss of reduction
      • immobilization
        • bend / cut pins
        • splint the arm
      • postoperative care
        • admit overnight to observe for compartment syndrome (may not be necessary in all cases)
        • see 1 week postoperatively with radiographs to ensure no loss of reduction
        • see 3 weeks postoperatively with radiographs and remove pins in office
          • allow full active ROM at that time
          • physical therapy is rarely needed
        • typically follow patients for 2-4 years after injury to ensure there is no growth arrest, deformity, or osteonecrosis (see below)
  • Complications
    • Cubitus varus
      • up to 70% have this complication
        • more common than with supracondylar fractures
      • cause
        • AVN of medial condyle
        • malunion (common because of missed diagnosis, or loss of reduction)
        • growth arrest
      • treatment
        • lateral closing wedge osteotomy
    • Medial or lateral condyle AVN
      • may lead to fishtail deformity seen in all distal humerus fractures
    • Loss of motion
      • usually no functional limitation
    • Growth disturbance
      • progressive cubitus varus
      • joint irregularities
      • angular deformity
      • limb-length discrepancy
      • treatment
        • observe initially, undertake surgery when > 5 years old
          • larger extremity
          • child more cooperative
          • can address all deformities in one surgery.
  • Prognosis
    • Often missed diagnosis as very difficult to diagnose
      • up to 50% missed by radiologist
    • In patients with early recognition and prompt treatment, outcomes are very good

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Flashcards (60)
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Questions (7)

(OBQ18.50) An 8-month-old boy was brought in by his parents for refusing to use his right arm after a fall off of the couch earlier in the evening. The patient's hand is otherwise well-perfused. Current imaging is shown in Figure A. After immobilization of the extremity which of the following is the next best step in treatment?

QID: 212946

Magnetic resonance imaging (MRI) of the elbow



Computed tomography (CT) of the elbow



CT of the head



Emergent fixation in the operating room



Contacting child protective services



L 3 A

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(OBQ12.120) Which of the following injuries shown in Figures A-E is most commonly the result of child abuse?

QID: 4480

Figure A



Figure B



Figure C



Figure D



Figure E



L 1 B

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(OBQ05.68) A 7-month-old girl cries when the mother touches her swollen left elbow. Figure A displays a series of radiographs. In Figure A, the images labeled A and B show the painful left elbow, while C and D are of the contralateral, non-injured elbow. What is the most appropriate treatment?

QID: 954

Open reduction and internal fixation



Closed reduction and percutaneous pinning



Closed reduction and casting



Functional bracing



Closed reduction and hinged external fixation



L 3 D

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(OBQ05.54) A 10-month-old child fell off of the couch and has left elbow pain and swelling. A radiograph is shown in Figure A. All of the following are characteristics of this injury pattern EXCEPT:

QID: 940

High risk of tardy ulnar nerve palsy



Posteromedial displacement



High association with child abuse



High risk of cubitus varus deformity



High risk of subsequent avascular necrosis of the medial condyle



L 4 D

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Evidence (6)
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