The posterior compartment of the forearm - extensor retinaculum (dave's notes)

Question 1

How wide is the extensor retinaculum of the wrist?

Answer 1

2.5cm

Question 2

Describe the extensor retinaculum.

Answer 2

A ribbon like band 2.5cm wide lying obliquely across the extensor surface of the wrist joint. This is a thickening of the deep fascia of the forearm.

Question 3

What is the proximal attachment of the extensor retinaculum?

Answer 3

Proximally attached to the radius above the stylohyloid process

Question 4

What is the distal attachment of the extensor retinaculum?

Answer 4

Distally attached to the pisiform and triquetral bones

Question 5

What nearby bone of significance is the extensor retinaculum of the wrist not attached to?

Answer 5

The ulna

Question 6

What is the function of the extensor retinaculum?

Answer 6

It maintains a constant tension throughout pronation and supination and holds down the extensor tendons

Question 7

What does the extensor retinaculum pass off? What does this create?

Answer 7

Firbrous septa pass to the bones of the forearm dividing the extensor tunnel into 6 compartments

Question 8

List the tendons passing under the extensor retinaculum from lateral to medial

Answer 8

Compartments from Lateral (radial):
1. APL/EPL - separate synovial sheaths usually
2. radial extensors of the wrist longus and brevis (sep sheaths)
3. EPL (own sheath)
4. The 4 tendons of ED (common synovial sheath)
5. EDMinimi (own sheath)
5. ECU (own sheath)
Medial (ulnar)