Large Animal Pelvic Limb

Question 1

How does the equine’s gluteal muscles differ from the dogs?

Answer 1

Horses have an accessory head to their middle gluteal (equivalent to canine’s Piriformis)

Question 2

Where is the Trochanteric Bursa located on an equine pelvic limb?

Answer 2

Located between the accessory head of the middle gluteal and the greater trochanter of the femur.

Question 3

What is the equivalent of the sacrotuberous ligament in the horse?

Answer 3

Sacrotuberous ligament attaches the sacrum to the ischiatic tuberosity.

In horses this ligament is a “sheet” that covers the whole side of the pelvis. This ligament is called the Sacrosciatic Ligament or the Broad Sacrotuberous Ligament.

Question 4

Is the gracilis part of the common calcaneon tendon in the dog? In the horse?

Answer 4

In the dog: YES

In the horse: NO

Question 5

What is the Symphysial Tendon?

Answer 5

Unites the left and right gracilis tendons on the ventral surface of the pelvis symphysis. It is an attachment site for other thigh muscles.

Present in both dogs and horses, but much more prominent in the horse.

Question 6

List the 5 retinacula of the equine pelvic limb, their locations and which tendons they hold down.

Answer 6

1. Proximal Extensor Retinaculum: dorsal surface at distal end of tibia. Holds down: Long Digital Extensor, Cranial Tibial and Pernoeus Tertius.
2. Middle Extensor Retinaculum: dorsal surface. Holds down: Long digital extensor.
3. Distal Extensor Retinaculum: dorsal surface. Holds down: Lateral Digital Extensor.
4. Lateral Extensor Retinaculum: lateral surface at level of the hock. Holds down: Lateral Digital Extensor.
5. Flexor Retinaculum: plantar surface. Holds down: DDF

Question 7

How does the arrangement of the Long Digital Extensor and Cranial Tibial muscle of the horse differ from the dog?

Answer 7

The Long Digital Extensor is cranial to the Cranial Tibial Muscle in the horse (opposite in the dog).

Question 8

What forms the reciprocal apparatus in the horse? What is the reciprocal apparatus?

Answer 8

Peroneus tertius and the SDF.
Reciprocal apparatus means that when the stifle is flexed, the hock is flexed. If the stifle is extended, the hock is extended.

Question 9

What happens if the peroneus tertius is torn?

Answer 9

Flexion of the stifle and extension of the hock.

Question 10

What happens if the SDF is torn?

Answer 10

Extension of the stifle and flexion of the hock.

Question 11

Where is the long plantar ligament in the horse? What does it do?

Answer 11

Long plantar ligament is attached to the distal end of the calcaneus and helps to counteract the upward force created by the common calcanean tendon.

Question 12

What is the Cunean Tendon?

Answer 12

It is the medial branch of the of the cranial tibial.

Question 13

Discuss the check ligaments in the equine pelvic limb.

Answer 13

There is no proximal check ligament of the SDF in the pelvic limb.
The DDF has a Distal Check Ligament (aka Accessory Ligament) between it and proximal aspect of Metatarsal III.

Question 14

Horses have a Transverse Acetabular Ligament and a Ligament of the Femoral Head (like the dog), but they also have another ligament. What is this ligament called? Where does it attach?

Answer 14

Accessory Ligament of the Femoral Head.

Runs from the head of the femur to the prepubic tendon (at the pubis).

Question 15

How many patellar ligaments does the horse have? How many does the dog have? List the patellar ligament(s) of the horse.

Answer 15

Horses have 3 patellar ligaments: Lateral Patellar Ligament, Middle Patellar Ligament, Medial Patellar Ligament.
Dogs have 1 patellar ligament.

Question 16

What are the 3 synovial sacs associated with the stifle of the horse? Where are they located? Which communicate?

Answer 16

1. Femoropatellar Sac - largest synovial cavity in the body. Found beneath the patella. The Infrapatella Fat Pad is found between this sac and the 3 patellar ligaments.
2. Medial Femorotibial Sac - found between the medial condyles of the tibia and femur. Communicates primarily with the femoropatellar sac.
3. Lateral Femorotibial Sac - found between the lateral condyles of the femur and tibia.

The 2 femorotibial sacs rarely communicate.

Question 17

List the 3 bursas of the calcaneus in the equine and their location.

Answer 17

1. Subcutaneous Calcaneal Bursa - between the skin and the SDF
2. Subtendinous (Intertendinous) Calcaneal Bursa of the SDF - between the SDF and the Gastrocnemius
3. Subtendinous Calcaneal Bursa of the Gastrocnemius - between the gastrocnemius and the calcaneus

Question 18

List the layers at the level of the calcaneus from external to internal in the horse.

Answer 18

Skin –> Subcutaneous Calcaneal Bursa –> SDF –> Subtendinous (Intertendinous) Calcaneal Bursa –> Gastrocnemius –> Subtendinous (Gastrocnemius) Calcaneal Bursa –> Calcaneus

Question 19

What are the 3 main components of the pelvic limb stay apparatus in the equine?

Answer 19

1. Patellar Locking Mechanism
2. The Reciprocal Apparatus
3. The Suspensory Apparatus

Question 20

Describe the patellar locking mechanism of the equine.

Answer 20

The medial patellar ligament and the parapatellar cartilage hook over the medial trochlear ridge of the femur.
Take muscular effort of the quadriceps to lock and unlock the patella.

Question 21

What is a capped hock?

Answer 21

Inflammation of the bursas in the hock due to trauma

Question 22

What is a Bone Spavin?

Answer 22

Osteoarthritis/Osteitis of the hock joint causing lameness. Usually occurs between the central and the 3rd tarsal bones as well as between the 3rd tarsal and 3rd metatarsal bones.

Question 23

What is curb?

Answer 23

Swelling at the back of the hock due to strain of the long plantar ligament.

Question 24

Which joints at the level of the tarsus communicate in the horse?

Answer 24

The Tarsocrural Joint and the Proximal Intertarsal Joint communicate.
Occasionally the Distal Intertarsal Joint and the Tarsometatarsal Joint communicate.

Question 25

Which tarsal bones are fused in the bovine?

Answer 25

The Central and 4th Tarsal bones are fused.

The 2nd and 3rd Tarsal bones are fused.

Question 26

Which tarsal bones are fused in the equine?

Answer 26

Tarsal bones 1 and 2.

Question 27

Which metatarsal bones are fused in the bovine?

Answer 27

Metatarsal 3 and 4

Question 28

Which metatarsal bones does the equine have?

Answer 28

Main metatarsal 3 with splint bones (metatarsals 2 and 4)

Question 29

How does the bovine gluteal muscles differ from the canine?

Answer 29

Does not have a superficial gluteal muscle because it is fused with the biceps femoris muscle. Fused muscle is called the: Gluteobiceps.

Cows have an accessory gluteal muscles like horses.

Question 30

How many patellar ligaments do cows have?

Answer 30

3 patellar ligaments. Just like the horse. But they cannot lock them!

Question 31

Do cows have a peroneus tertius?

Answer 31

YES! And a peroneus longus.