ZONE 1 FLEXOR TENDON INJURIES - OVERVIEW

Introduction

  • Zone I = area distal to the FDS insertion
  • Only the FDP is injured
  • Jersey finger: avulsion of the tendon from the distal phalanx
    • Leddy-Packer classification
      • Type I: tendon retracts into palm
      • Type II: tendon retracts to PIP joint
      • Type III: tendon entrapped at A4 pulley

Clinical Presentation

  • Symptoms
    • Loss of active flexion at DIP joint
  • Physical exam
    • Assess digital cascade and passive tenodesis effect
    • Assess skin integrity to help localize potential sites of tendon injury
    • Assess neurovascular status

Treatment

  • Impact of time
    • Acute (1-3 weeks): Direct repair
    • Chronic: repair up to 8 weeks if stuck at A4 (Type III)
    • Late: Palliative or (controversial) staged reconstruction 
      • No repair
      • DIP arthrodesis
      • Excise FDP scar
  • Surgical techniques
    • Exposure: Examine open wounds and extend as needed for visualization
    • Debride FDP insertion point on volar base of distal phalanx
    • Pass tendon through pulleys, preserving at least A2 and A4 pulleys
    • Core suture:
      • 2 strand with 2-0 prolene
      • 4 strand with 4-0 Becker sutures on side
    • Fixation/Repair
      • Primary end-to-end repair if long enough FDP stump present
      • Keith Needles on K-wire driver
        • Through distal phalanx sterile matrix and tie over button
        • Deep to stump along volar periosteum to fingertip and tie over button
        • Through P3 between nail bed and terminal extensor and tie over bone
      • Suture anchors into base of distal phalanx
    • More than 1cm of shortening increases risk of quadriga effect

Rehabilitation

  • Early passive ROM
  • Active motion and button cut off at 6 weeks
  • Full power grip at 3 months

Images

Figure1-Z1

Figure2-Z1

Figure3-Z1

Figure4-Z1

Figure5-Z1


References

Chang J, Noland S, Adams JE, Calfee R, Boyer M, Bozenta D, et al. “Tendon.”  ASSH Manual of Hand Surgery. Ed. Hammert WC. Philadelphia: Lippincott Williams & Wilkins. 2010. 93-110. 

Calfee RP. Zone I and II Flexor Tendon Repairs. Presentation at 2013 ASSH Annual Meeting.


 


Zone 1 Flexor Tendon Injuries Learning Module