Posterior Approach to Humerus

Cadaver dissection of the posterior approach to the humerus through a triceps split — Cadaver dissection of the posterior approach to the humerus through a triceps split. The asterisk marks the radial nerve on the posterior humeral shaft and the dot marks it at the lateral intermuscular septum. Image from Suwannaphisit S, Aonsong W, Suwanno P, Chuaychoosakoon C. Location of the radial nerve along the humeral shaft between the prone and lateral decubitus positions at different elbow positions. Sci Rep. 2021, 11(1), 17215. CC BY 4.0.

Posterior Approach to Humerus, triceps brachii, from gray’s anatomy — Triceps brachii, from Gray’s Anatomy. Image by Henry Vandyke Carter, Wikimedia Commons, Public domain.

Indications

ORIF
Osteomyelitis
Exploration of radial nerve

Position

Lateral
Axillary roll
Arm over radiolucent L bar

Landmarks

Acromion
Olecranon fossa

Incision

Longitudinal midline incision
Start: 8cm below acromion
End: olecranon fossa

Internervous Plane

Triceps splitting approach
- Medial head of triceps supplied by radial nerve
- Long head supplied by branch of axillary nerve

Superficial Dissection

Deep fascia
Triceps
- Superficial
  - Lateral head
    - Lateral lip of spiral groove (above spiral groove)
  - Long head
    - Infraglenoid tubercle
- Deep
  - Medial head
    - Below spiral groove
Ligate blood vessels

Deep Dissection

Incise medial head in midline
Subperiosteal dissection

Dangers

Nerve
- Radial nerve
- Ulnar nerve
Vessels
- Profunda brachii artery

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