Retinacula of the Hand and Wrist

Question 1

What are the attachments of the flexor retinaculum?

Answer 1

Medial - pisiform and hook of hamate

Lateral - scaphoid tubercle & both lips of groove of trapezium

Question 2

What is the function of the flexor retinaculum?

Answer 2

holds the long flexor tendons within the wrist to prevent bow stringing

Question 3

what is the flexor retinaculum?

Answer 3

Thickening of deep fascia forming the roof of the carpal tunnel

Question 4

What are the boundaries of the carpal tunnel?

Answer 4

Transverse osseous arch of carpal bones - form the floor

Laterally - scaphoid and trapezium

Medially - pisiform and hamate

superiorly - flexor retinaculum

Question 5

what passes through the main compartment of the carpal tunnel?

Answer 5

Laterally - flexor pollicis longus tendon
Median nerve

Medially - tendons of flexor digitorum superficialis and flexor digitorum profundus (deep)

Question 6

what passes through the small lateral compartment of the carpal tunnel?

Answer 6

tendon of flexor carpi radialis

Question 7

what is the distribution of tendon sheeths within the carpal tunnel?

Answer 7

Flexor carpi radialis - own sheeth
Flexor pollicis longus - own sheeth

Flexor digitorum profundus and flexor digitorum superficialis - common flexor sheeths around 8 tendons

Question 8

What is the role of the tendon sheath?

Answer 8

Protection

• decreases friction as tendons pass under the retincaulum

Question 9

what is the structure of the tendon sheath?

Answer 9

double walled synovial membrane extending around the tendon - visceral layer on tendon, with outer parietal layer.

cavity filled with synovial fluid

Question 10

What are the attachments of the extensor retinaculum?

Answer 10

Laterally - distal part of anterior surface of radius

Medially - distal end of ulna, ulna collateral ligament, pisiform and triquetral

Question 11

What is the extensor retinaculum?

Answer 11

an extension of the deep fascia of the back of the forearm and wrist.

Septa extend from deep surface to radius and ulna forming 6 canals

Question 12

What passes through the 1st compartment of the extensor retinaculum?

Answer 12

Tendons of abductor pollicis longus and extensor pollicis brevis (SHARED SHEATH)

Question 13

What passes through the 2nd compartment of the extensor retinaculum?

Answer 13

Tendons of extensor carpi radialis longus and extensor carpi radialis brevis
(SHARED SHEATH)

Question 14

What passes through the 3rd compartment of the extensor retinaculum?

Answer 14

Tendon of extensor pollicis longus

Question 15

What passes through the 4th compartment of the extensor retinaculum?

Answer 15

Tendons of extensor digitorum and extensor indicis

SHARED SHEATH

Question 16

What passes through the 5th compartment of the extensor retinaculum?

Answer 16

Tendon of extensor digiti minimi

Question 17

What passes through the 6th compartment of the extensor retinaculum?

Answer 17

Tendon of extensor carpi ulnaris

Question 18

What prevents ‘bowstringing’ of FDP and FDS in the phalanges?

Answer 18

fibrous sheaths form fibroosseous canals within the fingers