Rosen & Barkin's 5-Minute Emergency Medicine Consult (539 page)

DIAGNOSIS

• Mechanism of injury:
  
  • Hyperextension injuries most commonly cause ligamentous injury (e.g., “Jersey finger” which is a rupture of the flexor digitorum profundus tendon from its distal attachment) or chip fractures.
    
  • Hyperflexion injury to the tip of digits may cause “Mallet finger” injury with avulsion fracture at the insertion of the extensor tendon on the distal phalanx.
    
  • Crush injuries most commonly cause fractures and diffuse soft-tissue injury.
    
• Handedness
  
• Occupation/hobbies
  
• Other factors may affect healing (e.g., age, diabetes, immune suppression, anticoagulation)
  

• Swelling and/or deformity (e.g., amputation, rotation, shortening, or angulation)
  
• Skin changes (e.g., ecchymosis, laceration, burn, pallor) or associated nail injury
  
• Decreased range of motion or weakness
  
• Pain or change in sensation in the area of injury
  

In an infant with a painful or swollen digit, it is important to consider a deeply embedded hair tourniquet that may not be readily obvious on superficial exam.

• Special attention directed at assessing individual tendon status, neurovascular integrity, and identifying rotational deformity:
  
  • Isolate and assess each individual joint (PIP, DIP, MCP); range with passive motion and against active resistance
    
  • Normal 2-point discrimination is ∼4–5 mm
    
  • Malrotation can be evaluated by positioning the fingers with the MCP joints in flexion and the PIP and DIP in extension:
    
    • Normally, all fingers are directed toward the radius and there should be no overlap or rotation
      
• Exam conducted 1st to assess function, then under anesthesia, and finally with tourniquet if needed to allow a bloodless field for better exam of lacerated areas.
  

Consider wound culture if signs of infection present or if there is concern for flexor tenosynovitis.

• Plain radiography of involved digits should include AP, true lateral, and oblique views.
  
• US can help diagnose tendon tears.
  

Open epiphyses make radiographic interpretation less sensitive.

• Tendon laceration/rupture partial/complete
  
• Complicated open injuries may include several injuries, and the entire hand should be examined carefully.
  
• Beware of lacerations over dorsal metacarpal–phalangeal areas, which may be “fight bites” (human bites).
  

• Many fractures in children are torus (buckle) fractures of the phalanges.
  
• The growth plates are typically weaker than the surrounding ligaments, thus dislocations are commonly accompanied by Salter–Harris fractures.
  

TREATMENT

• Reduction of a phalangeal dislocation at the scene SHOULD NOT be considered UNLESS there will be an unusually long transport time or there is vascular or neurologic compromise.
  
  • Reduction may be successful but prompt the physician to miss significant ligamentous injuries.
    
• Bleeding should be treated with appropriate direct pressure dressings.
  

• Remove all rings from injured hand.
  
• Immobilize the involved areas by proximal-to-distal splinting.
  
• Intermittent ice pack application with constant elevation for the 1st 24 hr.
  
• Dislocations or severely deformed fractures producing vascular compromise should be reduced immediately to a neutral position and immobilized.
  

• Interphalangeal reduction:
  
  • Dorsal dislocation:
    
    • Provide longitudinal traction and gently hyperextend the joint while pushing the base of the dislocated phalanx into place.
      
  • Volar dislocation:
    
    • Provide longitudinal traction and gently hyperflex while pushing the base of the dislocated phalanx into place.
      
  • Lateral dislocation:
    
    • Provide longitudinal traction and gently hyperextend the joint while correcting the ulnar or radial deformity.
      
• Interphalangeal immobilization:
  
  • DIP dorsal or lateral finger dislocation:
    
    • Splint the DIP in full extension while allowing full range of motion of the PIP joint.
      
  • PIP dorsal or lateral finger dislocation:
    
    • Apply a dorsal splint with the PIP in 20–30° of flexion.
      
  • Volar finger dislocation:
    
    • Splint the PIP and DIP in full extension.
      
• Metacarpophalangeal dislocation:
  
  • Avoid excessive hyperextension or distraction. Gently distract the affected digit and apply volar pressure to the base of the dislocated proximal phalanx.
    
• Metacarpophalangeal immobilization:
  
  • Finger dislocation: Splint the digit in 90° of flexion at the MCP joint.
    
  • Thumb dislocation: Apply a thumb spica splint with the MCP joint in 20° of flexion.
    
• Open fracture:
  
  • Immediate referral to a hand surgeon for treatment within 4–6 hr after trauma.
    
  • Prophylactic antibiotics directed against gram-positive and gram-negative organisms should be administered parenterally within 6 hr.
    
• Closed fracture:
  
  • Distal phalanx:
    
    • Stable injuries may be splinted with the DIP in flexion and the PIP free; extend tip of splint beyond the end of the digit for added protection; maintain for 3–4 wk.
      
  • Middle phalanx:
    
    • Nondisplaced stable fractures can be buddy taped to an adjacent digit.
      
    • Displaced/angulated fractures may be reduced (using longitudinal traction with 3-point pressure to align the fragment) and immobilized (buddy tape and ulnar/radial gutter splint).
      
    • Splinting should be done with the wrist in 20–30° of extension, the MCP joints in 70–90° of flexion, and the PIP and DIP joints flexed 5–10°.
      
  • Proximal phalanx:
    
    • A nondisplaced, nonangulated, stable injury can be buddy taped to an adjacent finger; ulnar/radial gutter or Burkhalter splint may be added for comfort.
      
    • A displaced or angulated fracture may be reduced by flexing the MCP and PIP joints to 90°, then using a 3-point reduction technique to reduce the proximal fragment dorsally and the distal fragment volarly. Once reduced, the PIP joint should be extended (to avoid a flexion contracture), the MCP joint should remain in 70–90° of flexion and a radial or ulnar gutter splint should be placed with the fractured finger buddy taped to an adjacent finger.
      

• Evaluate tetanus status and vaccinate per immunization schedule.
  
• Digital nerve block should be done with an anesthetic that does NOT contain epinephrine.
  
• Antibiotics:
  
  • Not indicated for simple clean wounds
    
  • For grossly contaminated injury, puncture wounds, or infectious tenosynovitis therapy should be tailored to specific pathogen exposure (e.g., skin flora, fresh water, bites)
    

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