Courtesy: Prof Nabil Ebraheim, University of Toledo, Ohio, USA

Overview

Fractures of the radius and ulna shafts require precise surgical exposure to achieve anatomical reduction and stable fixation.

Key Principles

• Choice of approach depends on fracture location

• Each approach utilizes specific intermuscular planes

• Protection of neurovascular structures is critical

---

Approach to the Ulna Shaft

General Characteristics

• The ulna is subcutaneous along most of its length

• Allows direct and straightforward exposure

• Commonly approached from the dorsal aspect

---

Surgical Interval

• Between:

  • Flexor carpi ulnaris (FCU)

  • Extensor carpi ulnaris (ECU)

 Provides safe access to the ulnar shaft

---

Structure at Risk

Dorsal Cutaneous Branch of Ulnar Nerve

• Emerges ~5 cm proximal to the wrist

• Crosses toward the dorsum of the hand

 Must be protected, especially during exposure of the distal ulna

---

Surgical Approaches to the Radius Shaft

The radius can be exposed via:

• Volar (anterior) approach

• Dorsal (posterior) approach

 Selection depends on fracture location

---

Volar Approach to the Radius

---

Skin Incision

• Begins ~1 cm lateral to the biceps tendon insertion

• Extends distally toward the radial styloid

---

Intermuscular Planes

Distal Interval

• Between:

  • Flexor carpi radialis (FCR)

  • Brachioradialis (BR)

---

Proximal Interval

• Between:

  • Pronator teres (PT)

  • Brachioradialis (BR)

---

Indications

• Middle third radius fractures

• Distal third fractures

• Selected proximal fractures

---

Structures at Risk

During dissection, protect:

• Radial artery

• Superficial radial nerve

• Palmar cutaneous branch of median nerve

 Also consider structures lying beneath retractors

---

Modified Volar Approach (Distal Consideration)

• Median nerve lies between:

  • Palmaris longus

  • Flexor carpi radialis

Safer Technique

• Dissect along lateral border of FCR sheath

         Reduces risk of median nerve injury

---

Proximal Extension

• Maintains interval between:

  • Brachioradialis

  • Pronator teres

---

Structure at Risk

Posterior Interosseous Nerve (PIN)

• Must be protected during proximal dissection

---

Dorsal Approach to the Radius

---

Skin Incision

• Starts just anterior to the lateral epicondyle

• Extends distally along the dorsal forearm

---

Surgical Interval

• Between:

  • Extensor carpi radialis brevis (ECRB)

  • Extensor digitorum communis (EDC)

---

Deep Dissection

• The supinator muscle lies deep

• Must be carefully split to expose the radial shaft

---

Structure at Risk

Posterior Interosseous Nerve (PIN)

• Emerges from the supinator muscle

• Supplies extensor muscles

 Must be identified and protected

---

High-Risk Zone

• Junction of proximal and middle thirds of radius

 Area of greatest vulnerability for PIN injury

---

Summary of Surgical Intervals

Ulna

• FCU —}  ECU

---

Radius – Volar Approach

Proximal

• Brachioradialis — Pronator teres

Distal

• Brachioradialis — Flexor carpi radialis

---

Radius – Dorsal Approach

• ECRB –} EDC

---

Nerve Supply Patterns of the Forearm

---

Dorsal Compartment

• Supplied by:

  • Radial nerve

  • Posterior interosseous nerve (PIN)

---

Volar Compartment

• Primarily supplied by:

  • Median nerve

---

Important Exceptions

• Flexor carpi ulnaris (FCU) — Ulnar nerve

• Ulnar half of flexor digitorum profundus (FDP) — Ulnar nerve

---

Key Surgical Principle

Volar Approach

• Typically uses an internervous plane
   Between muscles supplied by:

• Median nerve

• Radial nerve

---

Dorsal Approach

• Most muscles share radial nerve supply

 Therefore:

• Greater emphasis on identifying and protecting the posterior interosseous nerve

---

Key Takeaways

• Ulna – subcutaneous, easy exposure

• Radius – requires careful approach selection

• Volar approach – safer internervous plane

• Dorsal approach – higher risk to PIN

• Always identify and protect:

  • Radial artery

  • Median nerve branches

  • Posterior interosseous nerve