Lecture 1: Small Animal Carpus and Forepaw

Question 1

What bones make up the carpus

Answer 1

Proximal carpal bones: ulnar, intermedioradial, accessory
Distal carpal bones: 1-4

Question 2

What are the 3 sections of metacarpal bones from proximal to distal

Answer 2

Base, body, head

Question 3

The 4th and 5th metacarpal bones articulate with which carpal bone

Answer 3

4th carpal bone

Question 4

What are the 3 phalanges from proximal to distal

Answer 4

Proximal phalanges, middle phalanges, and distal phalanges

Question 5

How many phalanges does the dewclaw have

Answer 5

2

Question 6

What is the purpose of sesamoid bones

Answer 6

Provide a smooth surface for fascia and act as levers/anchors and redistribute forces

Question 7

what bones are indicated by red box

Answer 7

Carpal bones

Question 8

what bones are indicated by the red box

Answer 8

Metacarpal bones

Question 9

What bones are indicated below the red line

Answer 9

Phalanges

Question 10

Case example: 8 month old, NM lab had box dropped on foot, immediately non-weight bearing lame. The following X-ray was took. What is causing lameness

Answer 10

Fractures to metacarpals 2-5

Question 11

What are the primary weight bearing metacarpals

Answer 11

3rd and 4th

Question 12

What are the secondary weight bearing metacarpals

Answer 12

2nd and 5th

Question 13

When assessing the prior case with fractures to metacarpals 2-5, what digits are most important to stabilize and why

Answer 13

3rd and 4th as they are the primary weight bearing metacarpals

Question 14

What can we do to treat the metacarpal fractures

Answer 14

Variety of options: pin, plate +/-splint

Question 15

What would be the best treatment option for fractures to metacarpals 2 and 5 and why

Answer 15

Can just splint as they are not weight bearing toes

Question 16

What two carpal ligaments are important for proper rotation of carpus

Answer 16

Medial and lateral collateral ligaments

Question 17

what carpal ligament is indicated by the arrow

Answer 17

Medial collateral ligament

Question 18

what carpal ligaments are indicated by arrows (red vs purple dot to distinguish sides)

Answer 18

Red: medial collateral ligament
Purple: lateral collateral ligament

Question 19

What structure prevents hyperextension of carpus and keeps paw in state of flexion

Answer 19

Palmar carpal fibrocartilage

Question 20

what is indicated by the blue arrow

Answer 20

Palmar carpal fibrocartilage

Question 21

What is indicated by blue arrow

Answer 21

Palmar carpal fibrocartilage

Question 22

Case example: 4yr, NM golden retriever jumped off 15ft sea well and acutely lame on right front. Right carpus is painful on flexion/extension and hyperextension of right carpus. X-ray shows the following. What could be the problem

Answer 22

Damage to carpometacaral joint, subluxation

Question 23

What are the three carpal joints

Answer 23

1. Antebraciocarpal (radial)
2. Intermediate (middle) carpal
3. Carpometacarpal

Question 24

Which carpal joint permits majority of the flexion and extension of carpus

Answer 24

Antebrachiocarpal joints

Question 25

What two carpal joints lack mobility

Answer 25

Intermediate (middle) Carpometacarpal

Question 26

identify the arrows most proximal to distal

Answer 26

1. Antebrachiocarpal joint 2. Intermediate (middle) carpal joint 3. Carpometacarpal joint

Question 27

How can you treat a subluxated Carpometacarpal joint

Answer 27

Can pin joint in place as it does not naturally have much mobility

Question 28

Case example: 3 month old, Great Dane, progressive forelimb lameness. The following picture represents the position of Buster’s forelimbs. What could be wrong

Answer 28

Carpal joints are hyperflexing—> carpal laxity syndrome

Question 29

In what dogs is carpal laxity syndrome most common

Answer 29

Young growing dogs who have either over or under supplemented diets, poor footing and improper exercise in growing puppies

Question 30

During carpal laxity syndrome there is weakness and irregular tension between what muscle groups

Answer 30

Extensor and flexor muscle groups

Question 31

What is the treatment of carpal laxity syndrome

Answer 31

Nutritional food, appropriate exercise, PT, generally resolves over time

Question 32

Identify 1-5 flexors of carpus

Answer 32

1. Superficial digital flexor 2. Flexor carpi ulnaris 3. Flexor carpi radialis 4. Deep digital flexor 5. Flexor retinaculum

Question 33

What nerves innervate the carpal flexors

Answer 33

Median and ulnar nerves

Question 34

identify the following extensors of carpus 1-3 and 6-7

Answer 34

1. Extensor carpi radialis 2. Common digital extensor 3. Lateral digital extensor 6. Abductor pollicus Longos 7. Extensor retinaculum

Question 35

What nerves innervate the extensors of carpus

Answer 35

Radial nerve

Question 36

What nerves must be blocked for declawing procedure

Answer 36

Radial, median and dorsal cutaneous branch of ulnar nerve

Question 37

What is the correct site of declawing

Answer 37

Removal of third phalanx

Question 38

What is polydactyly

Answer 38

Elongated 1st digit, additional digits on medial side of paw

Question 39

What is the most important food pad for weight bearing

Answer 39

Metacarpal pad

Question 40

What layer of skin is burned off and what kind of burn

Answer 40

Epidermis is burned off, dermis still present—> partial thickness burn

Question 41

What is the angular limb deformity seen in this photo

Answer 41

Carpal valgus

Question 42

what angular limb deformity is seen in this photo

Answer 42

Carpal varus

Question 43

what percent of radial and ulnar growth comes from the following growth plates

Answer 43

Humeroradial plate: 40% of radial growth Radiocarpal growth plate: 60% of radial growth Olecranon growth plate only makes olecranon longer Ulnar carpal growth plate: 85% of ulnar growth

Question 44

What happens to growth plates that can result in carpal valgus

Answer 44

Premature distal ulnar physeal closure therefore radial growth is unabated and results in angular changes

Question 45

What artery is a commonly used for blood pressure

Answer 45

Median artery

Question 46

what artery is indicated by #3

Answer 46

Median artery