Carpal Joint, Metacarpal Bones and Phalanges

Question 1

What are the main bony structures of the carpus? (7)

Answer 1

Intermedioradial carpal bone;

Ulnar carpal bone;

Accessory carpal bone;

First, second, third and fourth carpal bone.

Question 2

Where is there a small sesamoid bone with the carpus?

Answer 2

There is a small sesamoid bone within the distal tendon of the abductor pollicis longus muscle proximal and medial to the first metacarpal bone.

Question 3

What joint is:
Formed between the distal radius & ulna & the radial & ulna carpal bones

Answer 3

Antebrachial joint

Question 4

What joint is formed between the radial and ulnar carpal bones and 1st, 2nd, 3rd, and 4th carpal?

Answer 4

Middle carpal joint

Question 5

What joint is formed between the 1st, 2nd, 3rd and 4th carpal & the base of MC I, II, III, IV, V?

Answer 5

Carpometacarpal joint

Question 6

Where does the accessory carpal bone lie and articulate?

Answer 6

The accessory carpal bone lies on the caudal part of the ulnar carpal bone and articulates with the ulnar carpal bone and the styloid process of the ulna.

Question 7

How is the carpal joint stabilised?

Answer 7

Extra + intra articular ligaments

Question 8

Name the short ligaments on the dorsal surface of the carpus (3)

Answer 8

Short ulnar collateral
Dorsoradial carpal
Radioulnar

Question 9

Name the major deep ligaments of the carpus. (3)

Answer 9

Short radial collateral
Palmoulnocarpal
Palmerradiocarpal

Question 10

What is the anatomical sections of the metacarpal bones?

Answer 10

proximal base, a body and a distal head.

Question 11

What are the weight bearing MC?

Answer 11

III and IV

Question 12

Which MC joint only has 1 palmar sesamoid bones (cf to 2)

Answer 12

Metacarpopharyngeal joint I

Question 13

Which metacarpophalengeal joints have 1 dorsal sesamoid bone?

Answer 13

II-V

Question 14

Proximal, middle and distal phalanxes are present in digits…?

Answer 14

II - V

Question 15

What phalanx is present in digit I

Answer 15

Proximal + distal

Question 16

What support the metacarpophalangeal, proximal and distal interphalangeal joints medially and laterally?

Answer 16

Collateral ligaments

Question 17

What are hyperextension injuries caused by?

Answer 17

excessive loading of the limb due to a fall, running or twisting motion.

Question 18

Order the carpal luxations in the order of how common:
Proximal (antebrachial), middle carpal, Distal (carpometacarpal)

Answer 18

Middle carpal - 22%
Proximal (antebrachial) - 31%
Distal (carpometacarpal) - 47%

Question 19

How often is the antebrachial joint involved in cats with carpal injuries?

Answer 19

50%

Question 20

Capral subluxation more common in cats or dogs?

Answer 20

Cats

Question 21

Which carpal ligament had the highest elastic modulus?

Answer 21

accessorometacarpal ligaments

Question 22

Which carpal ligaments prevent hyperextension?

Answer 22

accessorometacarpal

Question 23

Which of the following is NOT a ligament of the carpus?
Long ulnar collateral ligament
Radioulnar ligament
Short ulnar collateral
Dorsal radiocarpal

Answer 23

Long ulnar collateral ligament

Question 24

On the approach to the carpal joint, how is the initial incision made?

Answer 24

The skin incision is made on the dorsal surface of the carpal joint. It extends from the juncture of the cephalic and accessory cephalic veins to the middle third of the metacarpus. The incision is made lateral to the accessory cephalic vein and curves laterally at its distal end to follow the vein.

Question 25

Approach to the carpus:
The deep antebrachial fascia is incised between the tendon of the A) and the tendon of the B) from the abductor pollicis longus muscle proximally to the proximal metacarpal bones distally.

Answer 25

A) extensor carpi radialis
B) common digital extensor

Question 26

On the approach to the carpus how is the periosteum incised + elevated?

Answer 26

Medially and laterally

Question 27

What movement facilitates exposure of the various joint spaces in the carpal joint?

Answer 27

Flexion

Question 28

How are individual carpal bone exposed?

Answer 28

The joint capsule around each carpal bone has to be incised

Question 29

For pancarpal arthrodesis or distal radial fracture repair additional exposure of the distal third of the radial diaphysis is required. How is this done?

Answer 29

The skin incision is extended proximally and should be located lateral to the cephalic vein, so that the vein and accompanying superficial branches of the radial nerve are all displaced medially with the skin margin.

Question 30

What retractors for the carpus?

Answer 30

Gelpi

Question 31

When is additional exposure of the distal third of the radial diaphysis needed? (2)

Answer 31

• Pancarpal arthrodesis
• Distal radial #

Question 32

Carpus approach:
After A) retraction of the B) the origin of the C) is sharply incised from the periosteum of the radius along its lateral margin.

Answer 32

A) Lateral
B) Common digital extensor tendon
C) Abductor Pollicis Longus m.

Question 33

Carpus approach:
After A) retraction of the B) the synovial sheath surrounding the C) is incised longitudinally and displaced laterally out of the lateral sulcus on the distal end of the radius.

Answer 33

A) Medial
B) Abductor Pollicis Longus m.
C) Common digital extensor tendon

Question 34

What are used to displace the extensor carpi radialis and abductor pollicis longus tendons medially.

Answer 34

Gelpi retractors

Question 35

What tendon is released from the synovial sheath and the middle sulcus on the distal radius?

Answer 35

Extensor carpi radialis

Question 36

What is transected to achieve Greater exposure of the carpal joints?

Answer 36

The insertions of the extensor carpi radialis tendons from the base of metacarpal bones II and III, respectively.

Question 37

What is incised to expose the articular cartilage surfaces?

Answer 37

The underlying joint capsule of the antebrachiocarpal joint