II. Anatomy: Dorsal Hand Zones (Extensor Hand)

  1. Zone 1: DIP Joint and Distal Phalanx (including Fingernail)
  2. Zone 2: Middle Phalanx
  3. Zone 3: PIP Joint and Proximal Phalanx
  4. Zone 4: MCP Joint
  5. Zone 5: Distal Metacarpals
  6. Zone 6: Proxmal Metacarpals
  7. Zone 7: Distal wrist and Carpal Bones
  8. Zone 8: Proximal wrist and Carpal Bones

III. Signs

  1. Variable loss of active finger extension
  2. Inspect all Lacerations for Tendon Injury
  3. Metacarpal-phalangeal joint (MCP) may be most difficult
    1. Tendon retracts most at this location
  4. Exploration may require Laceration extension
    1. Allows for tendon visualization

IV. Imaging

  1. XRay Hand Indications
    1. Evaluate for Retained Foreign Body (Radiopaque Foreign Body)
    2. Concurrent Fractures
    3. Joint injury

V. Management: Repair

  1. Open Extensor Tendon Lacerations are amenable to Emergency department repair
    1. Contrast with flexor tendon injuries which are made more complicated by anatomy (e.g. tendon sheaths)
  2. Indications: Extensor tendon repair
    1. Full tendon Laceration
    2. Partial tendon Laceration over 33% of tendon
  3. Contraindications for emergency department extensor tendon repair
    1. Neurovascular injury
    2. Thumb injury
    3. Zone 7 or 8 injury (distal wrist)
    4. Significant wound contamination or tissue destruction
    5. Closed Tendon Injury
    6. Associated Fractures
  4. Laceration evaluation
    1. Extensive Wound Irrigation
    2. Evaluate for retained Skin Foreign Body
  5. Direct end to end repair of tendon
    1. Technique: Kessler Repair
      1. Wound Irrigation and exploration as above
      2. Extend fingers to best visualize tendon segments
      3. Consider proximal penrose drain or Blood Pressure cuff inflation
        1. May improve visualization if blood obscures surgical field
      4. Use braided non-Absorbable Suture (nylon) 4-0
      5. Proximal Tendon Segment
        1. Grasp proximal tendon end in forceps
        2. Suture enters medial (radial) tendon and exits on dorsal aspect tendon
        3. Suture loops behind tendon ventrally from medial to lateral
        4. Suture enters lateral (ulnar) tendon and exits on dorsal aspect of tendon
      6. Distal Tendon Segment
        1. Grasp distal tendon end in forceps
        2. Suture enters lateral (ulnar) tendon and exits on dorsal aspect of tendon
        3. Suture loops behind tendon ventrally from lateral to medial
        4. Suture enters medial (radial) tendon and exits on dorsal aspect tendon
        5. Tie the 2 Suture ends together
        6. Attempt to bury knot and cut the Suture ends close to the knot
      7. Perform Laceration Repair
    2. Disposition
      1. Splint wrist and finger in extension for 4 weeks
      2. Follow-up with hand surgery in 5-7 days
  6. Alternative: Deferred Repair
    1. Wound Irrigation and Laceration Repair
    2. Splint wrist and fingers in extension
    3. Urgent referral to hand surgery for definitive tendon repair

VI. References

  1. Warrington, David and Deaton (2020) Crit Dec Emerg Med 34(12): 15

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