Extensor Pollicis Longus (EPL) Anatomy

  • Origin: Ulna (posterolateral surface of middle shaft) Interosseous membrane
  • Insertion: Thumb (base of distal phalanx, dorsal side)
  • Innervation: Cervical roots: C7 and C8
  • Nerve: Radial nerve (posterior interosseous branch)
Diagrams & Photos
  • Note EPL, EPB, first dorsal interosseous, adductor pollicis, EDC, and EIP.
    Note EPL, EPB, first dorsal interosseous, adductor pollicis, EDC, and EIP.
  • Extensor Pollicis Longus (EPL)
    Extensor Pollicis Longus (EPL)
  • Extensor Pollicis Longus (EPL)
    Extensor Pollicis Longus (EPL)
Videos
EPL, EPB & APL Video
Key Points
  • The extensor pollicis longus (EPL) usually retracts vigorously after laceration proximal to its connections to the extensor hood at the thumb MP joint.
  • The retracted extensor pollicis longus (EPL) can develop a contracture of the muscle tendon complex very quickly, therefore, an early repair is essential. 
  • Late treatment for a neglected extensor pollicis longus (EPL) laceration will frequently require reconstruction with a EIP tendon transfer.
Anatomy References
Anatomic Abbreviations
Hand Surgery Resource Anatomy Diagnostic Guide (Chapter)