Upper Limb Structures of the Hand

Question 1

What are the two types of joints in the hand?

Answer 1

Metacarpophalangeal joints, knuckles.

Interphalangeal joints, two in each digit apart from thumb.

Question 2

What type of joint is the metacarpophalangeal joint?

Answer 2

Condyloid joints.

Question 3

What are the two types of interphalangeal joints in the hand?

Answer 3

Proximal interphalangeal joints and distal interphalangeal joints.

Question 4

What are the six movements of the hand?

Answer 4

Flexion of digits at each MCPJ, PIPJ, and DIPJ.
Extension of digits at each MCPJ, PIPJ, and DIPJ.
Abduction of digits, moving them away from the midline.
Adduction of digits, moving them towards the midline.
Opposition of the thumb and little finger.
Reposition of the thumb and little finger.

Question 5

What is the palmar aponeurosis?

Answer 5

Fibrous connective tissue that thickens in the centre of the hand. Continuous with the palmaris longus tendon and flexor retinaculum.

Question 6

What are the fibrous digital sheaths?

Answer 6

When the palmar aponeurosis fans out distally into four digital rays.

Question 7

What is Dupuytren contracture?

Answer 7

A disease that presents with partial flexion of one or more of the fingers as a result of thickening of the palmar fascia due to fibrosis.

Question 8

How can Dupuytren contracture be treated?

Answer 8

Surgery to relive the tension in the connective tissue.

Question 9

What is the flexor retinaculum?

Answer 9

Thick strip of connective tissue that forms the roof of the carpal tunnel. It attaches medially to the pisiform and hook of hamate and laterally to the trapezium and scaphoid.

Question 10

What is the role of the extensor retinaculum?

Answer 10

Thickening of fascia ont he dorsum of the hand to keep the extensor tendons in position, to prevent bowstringing.

Question 11

What is the role of palmar/ volar plates?

Answer 11

On the palmar surface of each MCP and IP joints, they limit hyperextension of the digit and therefore enhance stability.

Question 12

How do the collateral ligaments work?

Answer 12

They are taut when the fingers are flexed to limit adduction. But they are lax when the fingers are extended to allow abduction.

Question 13

What movement of the fingers do the flexor digitorum supericialis and profundus allow?

Answer 13

Flexion of the fingers.

Question 14

How do FDS and FDP enter the hand?

Answer 14

Through the carpal tunnel.

Question 15

What are the FDS and FDP protected by in the hand?

Answer 15

The common flexor sheath.

Question 16

Where do the tendons of FDS and FDP insert?

Answer 16

FDS tendon splits near the base of the proximal phalanx and inserts into the intermediate phalanx. The FDP tendon passes through and inserts onto the distal phalanx.

Question 17

What happens to extensor tendons in the fingers as they reach the metacarpals?

Answer 17

They flatten and become extensor expansions, hoods. These fan out and wrap around the metacarpals and proximal phalanx joining onto the palmar plate.

Question 18

How do the fingers extend?

Answer 18

Contraction of the extensor digitorum muscle tightens the extensor tendons and acts on the attachments to extend the fingers.