Anatomy of cubital fossa and contents of cubital fossa

 

WHAT IS THE CUBITAL FOSSA?

Cubital (Latin cubitus, elbow) fossa is a triangular shaped situated on the front of the elbow between the forearm and the arm on the anterior surface of the elbow, with the apex of the triangle  pointing distally.

It is homologous with the popliteal fossa of the lower  limb situated on the back of the knee.

Features

Cubital (Latin cubitus, elbow) fossa is a triangular hollow situated on the front of the elbow (it is homologous with the popliteal fossa of the lower limb situated on the back of the knee.)

Boundaries

Laterally - Medial border of the brachioradialis

Medially -  Lateral border of the pronator teres. 

Base - It is directed upwards, and is represented by an imaginary line joining the front of two epicondyles humerus. 

Apex - It is directed downwards, and is formed by the area where brachioradialis crosses the pronator teres muscle.

Roof

The roof of the cubital fossa is formed by:

a. Skin.

b. Superficial fascia containing the median cubital vein joining the cephalic and basilic veins. The lateral cutaneous nerve of the forearm lies along with cephalic vein and the medial cutaneous nerve of the forearm along with basilic vein.

C. Deep fascia. 

d. Bicipital aponeurosis.

The main contents of the cubital fossa

The fossa is actually very narrow. The contents described are seen after retracting the boundaries. From  medial to the lateral side, the contents are as follow:

1.The median nerve:

 It gives branches to flexor carpi radialis, palmaris longus, flexor digitorum Superficialis and leaves the fossa by passing between two heads of pronator teres. 

2. brachial artery

 The termination of the brachial artery, and the beginning of the radial and ulnar arteries lie in the fossa.
The radial artery is smaller and more superficial than ulnar artery. It gives off the radial recurrent branch. The ulnar artery goes deep to both heads of pronator teres and runs downwards and medially, being separated from the median nerve by the deep head of the pronator teres. 
 Ulnar artery gives off the anterior ulnar recurrent, the posterior ulnar recurrent, and the common interosseous branches.

The common interosseous branch divides into the anterior and posterior interosseous arteries, and latter gives off the interosseous recurrent branch. 

3. biceps brachii

 The tendon of the biceps brachii, With the bicipital aponeurosis.

4.The radial nerve: 

It desends medial to lateral epicondyle to enter cubital fossa. In the fossa it gives off the posterior interosseous nerve or deep branch of the radial nerve which gives branches to extensor capri radialis brevis and supinator. Then it leaves the fossa by piercing the supinator muscle. 
The remaining superficial branch runs in the front of forearm for some distance.

CLINICAL ANATOMY

The cubital region is important for the following reasons:

a. The median cubital vein is often the vein of Choice for intravenous injections.
b. The blood pressure is universally recorded by auscultating the brachial artery in front of the elbow.
The anatomy of the cubital fossa is useful while dealing with the fracture around the elbow, like the supracondylar fracture of the humerus.