Approach to Posterior Radius

Dorsal (Thompson) approach to the proximal radius
Dorsal (Thompson) approach to the proximal radius. The posterior interosseous nerve (B) is seen running through supinator (D), with extensor carpi radialis brevis (E) retracted and the radial shaft (A) below. Image from Kumar J, Moses A, Young P, Gitlin A. Contralateral Distal Fibula Plate for Proximal Radius Fracture, A Technical Case Report. Cureus. 2025, 17(8), e90558. CC BY 4.0.
Approach to Posterior Radius, dissection of the posterior forearm showing the extensor muscles
Dissection of the posterior forearm showing the extensor muscles. Image by Anatomist90, Wikimedia Commons, CC BY-SA 3.0.

Thompson Approach

Position

  • Supine
  • Forearm pronated

Landmarks

  • Lateral epicondyle of humerus
  • Lister’s tubercle

Incision

  • Straight longitudinal incision
  • Start anterior to lateral epicondyle
  • End just ulnar to Lister’s tubercle
  • Use whatever part that is necessary

Internervous Plane

Superficial Dissection

  • Deep fascia
  • Identify interval between ECRB & EDC distally

Deep Dissection

  • Proximal 1/3
    • Radius is covered by supinator
      • PIN is between superficial & deep heads & arises 1cm proximal to distal edge
    • Identify & preserve PIN
      • Mobilise the nerve by carefully dissecting it through substance of supinator
    • Supinate forearm
      • Detach Supinator from origin subperiosteally
    • Middle 1/3 
      • Radius covered by 
        • APL
        • EPB
    • Distal 1/3
      • Identify interval between EPL and ECRB

Dangers

  • PIN

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 10 October 2026.