Learning Objectives

By the end of this section, the learner should be able to:

1. Describe the location and function of the cubital fossa
2. Identify the borders, roof, and floor of the cubital fossa
3. List the contents in correct lateral-to-medial order
4. Apply anatomical knowledge to understand the clinical relevance, particularly supracondylar fractures

---

Overview

The cubital fossa (also known as the antecubital fossa) is a triangular-shaped depression located on the anterior aspect of the elbow joint.

It serves as an important transition zone between the arm and the forearm, allowing major neurovascular structures to pass between these regions.

---

Borders, Roof, and Floor

The cubital fossa is triangular in shape and is defined by three borders, a roof, and a floor:

Borders

• Lateral border: medial border of the brachioradialis muscle
• Medial border: the lateral border of the pronator teres muscle
• Superior border: an imaginary horizontal line connecting the medial and lateral epicondyles of the humerus

Roof

• Skin
• Superficial fascia and subcutaneous fat
• Bicipital aponeurosis (reinforced by deep fascia)

Floor

• Brachialis muscle (proximally)
• Supinator muscle (distally)

---

Contents

The cubital fossa functions as a passageway for structures travelling between the upper arm and forearm.

Its contents are arranged from lateral to medial as follows:

1. Radial nerve
   1. Lies along the lateral margin of the fossa
   2. Divides into superficial (sensory) and deep (motor) branches
   3. Supplies the posterior forearm and hand
2. Biceps brachii tendon
   1. Passes centrally through the fossa
   2. Inserts onto the radial tuberosity
   3. Gives rise to the bicipital aponeurosis, which contributes to the roof
3. Brachial artery
   1. Lies medial to the biceps tendon
   2. Bifurcates into the radial and ulnar arteries at the apex of the fossa
   3. The brachial pulse can be palpated just medial to the biceps tendon
4. Median nerve
   1. Most medial structure within the fossa
   2. Exits by passing between the two heads of the pronator teres
   3. Supplies the anterior forearm and hand (motor and sensory)

Superficial veins in the roof

• Includes the median cubital vein, which connects the cephalic and basilic veins
• Commonly used for venepuncture due to its size and accessibility

Mnemonic (lateral → medial): Really Need Beer To Be At My Nicest
Radial nerve → Biceps tendon → Brachial artery → Median nerve

---

Activity

---

Clinical Relevance: Supracondylar Fracture

A supracondylar fracture is a fracture of the distal humerus, most commonly caused by a fall on an outstretched hand. It is especially common in children.

Because of the proximity of vital structures within the cubital fossa, this injury may result in:

Brachial artery injury

• Can lead to Volkmann’s ischaemic contracture, caused by muscle ischemia and fibrosis of the forearm flexors

Nerve injuries, including:

• Anterior interosseous nerve (branch of the median nerve)
  • Tested by asking the patient to make an “OK” sign
• Radial nerve
• Ulnar nerve

---

Gartland Classification of Supracondylar Fractures

• Type I: Minimally displaced
• Type II: Displaced with intact posterior cortex
• Type III: Completely displaced

Management

• Type I: Conservative treatment with an above-elbow cast
• Types II and III: Surgical fixation, typically using crossed bi-cortical K-wires

---

Activity