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, AbPL, and Lister's tubercle.
    Note EPL, EPB, AbPL, and Lister's tubercle.
  • EPL
    EPL
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)