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Extensor Tendon Injuries (Hand)

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Other Names

  • Extensor tendinopathy


  • Generally a loss of ability to extend the affected digit, hand and/or wrist
  • Superficial, susceptible to injury
  • Most common finger is pointer/ index finger
  • Potential mechanisms are sharp object direct lacerations, burns, blunt trauma, bites, crush injuries, avulsions and deep abrasions


  • Can affect MCPJ and/or PIPJ or DIPJ of hand
  • Zone 1: Traumatic flexion of DIPJ
  • Zone 2: Dorsal laceration or crush injury
  • Zone 5: Fight bite

Risk Factors

  • Unknown

Differential Diagnosis

Clinical Features

  • General: Physical Examination Hand
  • Universally present with inability to extend at some point on dorsal finger, hand or wrist
  • Inspect for etiology (laceration, crush trauma, overuse, etc)
  • Zone 1: Loss of extensor mechanism at DIPJ (digits 2-4), IPJ (thumb)
  • Zone 3: Elson's Test can help confirm diagnosis



  • Zone 1: DIPJ
    • Injury to terminal extensor tendon distal to or at the DIPJ (digits 2-4) or IPJ (thumb) involving EPL
    • Sequelae: Mallet Finger
  • Zone 2: Middle Phalanx
    • Injury of tendon over middle phalanx (digits 2-4), or proximal phalanx thumb
  • Zone 3: PIPJ
  • Zone 4: Proximal Phalanx
    • Injury over the proximal phalanx (digits 2-4) or metacarpal of thumb (EPL, EPB)
  • Zone 5: MCPJ
    • Injury over MCPJ of digit (2-4) or CMCJ of thumb (EPL, EPB)
    • Sequelae: Fight Bite, Sagittal band rupture
  • Zone 6: Metacarpals
    • Injury over the metacarpal
    • Sequelae: Increased risk of neurovascular injury
  • Zone 7: Wrist
    • Injury at wrist joint
    • Surgical injury requiring repair of extensor retinaculum
  • Zone 8: Distal third of forearm
    • Disruption at the distal forearm
  • Zone 9: Muscle belly rather than tendon injury
    • Sequelae: High risk of neurologic injury, requires surgery



  • Depends on zone of injury
  • Immobilization if <50% of tendon cut and extensor tendon remains intact
  • DIPJ extension splint
    • Zone 1 (mallet finger)
  • PIPJ extension splint
    • Zone 3 (central slip if simple)
  • MCPJ extension splint
    • Zone v (closed, uncomplicated sagittal band rupture)


  • Incision & drainage: Open fracture involving joint, fite bite
  • Repair: tendon laceration >50%
  • Fixation: volar avulsion fracture
  • Reconstruction: tendon repair not possible
  • Central slip reconstruction

Return to Play

  • Needs to be updated


  • Neurovascular injury

See Also



Created by:
John Kiel on 16 August 2019 23:11:13
Last edited:
16 October 2022 00:17:41