Pediatric Elbow Dislocation

HPI:  Pediatric male presents after a fall onto outstretched arm with obvious deformity to right elbow.  

PE:  Patient is unable to cross fingers and has paresthesias in the ulnar nerve distribution.  Initial radiograph showed posterior dislocation with questionable hyperdensity representing the medial epicondyle.  We were unable to reduce under fluoroscopy as the medial epicondyle was more visible and the patient eventually required ORIF.

Imaging: AP and lateral radiograph of the elbow

Image 1: Showing associated medial epicondyle fracture

How to Diagnosis: Two important lines help in making the diagnosis; radiocapitella and anterior humeral.

Radiocapitellar line:  Drawn through the center of the radial neck and should pass the center of the capitellum as shown below

Anterior humeral line:  Drawn through the lateral view of the surface of the humerus and should pass through the middle of the capitellum

Ossification: 6 sites that fuse at different ages.  Mnemonic = CRITOE

• C - Capitellum
  
• R - Radius
  
• I - Internal (medial) epicondyle
  
• T - Trochlea
  
• O - Olecranon
  
• E - External (lateral) epicondyle
  

Ossify around 1-3-4-7-9-11
 
Treatment: Nonoperative with closed reduction and early range of motion (1-2 weeks) is most common.  ORIF required for incarcerated medial epicondyle, inability to obtain close reduction, or significant instability.

Pearls:

• Most common mechanism is fall on outstretched hand
  
• Reduction technique involves gradual axial traction starting in full extension and moving towards full flexion
  
• Consider child abuse in all cases if story does not fit injury
  
• Brachial artery and median nerve most commonly injured
  
• Ulnar nerve injury more common with medial epicondyle avulsion