Equine distal limb variations and the stay apparatus

Question 1

What aspect of the distal limb are extensor tendons located?

Answer 1

Dorsal aspect

Question 2

What aspect of the limb are flexor tendons located?

Answer 2

palmar aspect

Question 3

What type of tendons run through the carpal canal?

Answer 3

flexor tendons

Question 4

What are the boundries of the carpal canal?

Answer 4

Dorsal- palmar aspect of the carpal joint capsule
Lateral- ACB
Palmar- Palmar/ flexor retinaculum

Question 5

Whar are the contents of the carpal canal?

Answer 5

DDFT
SDFT
Blood vessels
Nerves

Question 6

What is the function of the fluid filled tendon sheath?

Answer 6

Protects tendons that pass through confined spaces

Question 7

What holds the CDE in place?

Answer 7

retinaculum

Question 8

What holds the SDFT and DDFT in place?

Answer 8

Carpal canal
Annular ligaments

Question 9

What limits the length of the SDFT and DDFT?

Answer 9

Check ligaments

Question 10

What would inflammation of the tendon sheaths result in?

Answer 10

Increased fluid volume and pressure
Bulge ges proximally and distally

Question 11

How would you be able to tell that a bulge was an inflammed tendon sheath and not a mass?

Answer 11

It would move

Question 12

Where are 3 places that swellings are normally seen in the distal limb of the horse?

Answer 12

1. splints
2. joint capsule (between suspensory ligament and MC/MT3)
3. Tendon sheath (palmar to suspensory ligament and proximal to annular ligament

Question 13

What diagnostic imaging technique would be useful for diagnosis and monitoring healing post lesion in the distal limb of a horse?

Answer 13

Ultrasound

Question 14

Where would a chestnut be located on a horse?

Answer 14

Antebrachium

Question 15

What bone of a horse is a chestnut thought to be a reminant of?

Answer 15

1st metacarpal bone

Question 16

What is a chestnut?

Answer 16

Vestigual horn pad

Question 17

What is an ergot?

Answer 17

Horny lump in skin

Question 18

Where is an ergot located?

Answer 18

Palmar aspect of MCP joint

Question 19

True/False?
Most of the weight of the horse is borne on the forelimb?|

Answer 19

True

Question 20

What is required for a limb to be kept upright?

Answer 20

Maintenance of all joints in weight-bearing extension

Question 21

What is the equine stay apparatus?

Answer 21

Structures that prevent the collapse of the joints into flexion or hyperextension

Question 22

What should be prevented in the proximal limb joint for a horse to remain in a standing position?

Answer 22

Flexion

Question 23

What should be prevented in the carpus for a horse to remain in a standing position?

Answer 23

Flexion and hyperextension

Question 24

What should be prevented in the distal limb joints of the horse for it to remain in a standing position?

Answer 24

Hyperextension

Question 25

What role does the serratus ventralis muscle play in enabling the horse to remain in standing position?

Answer 25

Suspends weight of body between forelimbs

Question 26

At the level of the shoulder what muscle plays a role in the stay apparatus and how does it do this?

Answer 26

Biceps brachii
Maintains shoudler joint in extension

Question 27

What structures/ features of the elbow play a role in the stay apparatus?

Answer 27

• Collateral ligaments
• Alignment of bones

Question 28

What plays a role in the stay appartus by preventing flexion of the carpus in the horse?

Answer 28

Lacertus fibrosis

Question 29

What prevents hyperextension of the carpus?

Answer 29

• Palmar fibrocartilage joint reinforcement
• SDFT and check ligament
• Retinaculum

Question 30

What prevents hyperextension of the MCP,PIP and DIP joints?

Answer 30

-DDFT
- SDFT
(associated check and annular ligaments)

Question 31

What prevents hyperextension of the MCP/fetlock joint?

Answer 31

• Suspensory ligament
• CDE
• Proximal sesamoids
• Distal sesamoidean ligaments (short, cruciate, oblique and straight)