Joints of the appendage

Question 1

Joints

Answer 1

• Officially called articulations
• Purpose: unite bones firmly OR permit free movement
• 3 major categories

Question 2

3 types of joints

Answer 2

1. Fibrous joints
2. Cartilaginous joints
3. Synovial joints

Question 3

Fibrous joints

Answer 3

bones united by dense connective tissue

ex. Interosseous ligament (attaches radius to ulna)

Ex. gomphosis (anchors tooth to bone)

Ex. sutures (join bones of skull

Question 4

Cartilaginous joints

Answer 4

bones united by cartilage (including fibrocartilage)

Ex. epiphyseal plate

Ex. pelvic symphysis (joins pubic and ischial bones)

Ex. joint between adjacent vertebral bodies

Question 5

Synovial joints

Answer 5

Bones separated by fluid-filled cavity

Ex. Movable joints of the appendages

Question 6

Numerical classification of synovial joints

Answer 6

1. Simple- one pair of articular surfaces. Ex. shoulder
2. Composite- more than two articular surfaces. Ex. elbow

Question 7

Parts of a synovial joint

Answer 7

• Articular cartilage lines end of bones separating bone from joint cavity
• Joint capsule composed of synovial membrane and sometimes a fibrous cavity and layer of fat
• Synovial joint pouches- build up of fluid, great for injections.

Question 8

Unique components of joint capsules

Answer 8

• synovial fluid can extend and wrap around joint
• Many pouches stick out and can communicate with other pouches due to free flowing fluid

Question 9

Joint capsules in Horses

Answer 9

Cruciate ligaments have created compartments in the horse so that the fluid is no longer flowing. Will need to draw/inject in more or less places.

Question 10

Synovial joint types

Answer 10

1. Plane
2. pivot
3. ellipsoidal
4. spheroidal
5. hinge
6. condylar
7. saddle

Question 11

Plane synovial joint

Answer 11

No change in angle of the joint. Two flat surfaces sliding

Ex. Vertebra

Ex. Between tarsal and carpal joints within the row

Question 12

Pivot synovial joint

Answer 12

Peg and ring

Ex. Radial joint of ulna

Ex. Head and neck

Question 13

Ellipsoidal synovial joint

Answer 13

Ex. carpus joint

Allows all movement except only has minimal circumduction

Question 14

Spheroidal synovial joint

Answer 14

Ball and socket joint. Fibrocartilagionous labrum attaches to rim of socket preventing it from popping out.

Greatest versatility of movement… however less movement in shoulder of 4 legged animals

Ex. Hip joint

Ex. Shoulder joint

Question 15

Hinge synovial joint

Answer 15

Moves in one plane. The other movements are prohibited by articular surface shape (matching grooves and ridges) and collateral ligaments.

Ex. Elbow

Question 16

Condylar synovial joint

Answer 16

Two knuckle-shaped condyles that articulate with corresponding concave surfaces.
Mainly one plane, but able to do slight rotation and slide

Ex. Condyles of tibia and fibula

Question 17

Saddle synovial joint

Answer 17

One side is concave and one side is convex.

Biaxial, not much abduction or adduction

Ex. coffin joint

Question 18

Dog Elbow joint

Answer 18

Has 5 ligaments:
1. Medial collateral ligament
2. Lateral collateral ligament
3. Annular ligament of radius
4. Oblique ligament
5. Olecranon ligament

Question 19

Ligaments

Answer 19

Thickenings of fibrous layer of joint capsule

Question 20

Why are there differences between the elbow ligaments of a dog and horses?

Answer 20

Dogs and cats have more ligaments because there is a lot of movement between the ulna and radius whereas horse ulna and radius are fused and have less movement.

Question 21

What is the purpose of the fibrocartilaginous labrum in the spheroidal joints?

Answer 21

Extends the pocket and prevents bone from popping out.

Ex. Dogs that have hips that pop out often have narrow acetabulums

Question 22

Role of teres major and teres minor in

Answer 22

Cancel each other out and prevent each other from performing their desired rotation.

Question 23

Stifle joint components

Answer 23

1. Cranial cruciate ligament
2. caudal cruciate ligament
3. medial menisci
4. lateral menisci

Question 25

Role of the medial and lateral menisci of the stifle joint

Answer 25

C- shaped fibrocartilaginous disk that compensate for incongruities between the femur and tibia

Act as shock absorbers

Question 25

Role of the cranial cruciate ligament of the stifle joint

Answer 25

Prevents the femur from sliding caudally down tibial plateau when appendage bears weight

Question 25

Role of the caudal cruciate ligament of the stifle joint

Answer 25

Prevents femur from sliding cranially when appendage bears weight

Question 26

How do the cranial and caudal cruciate ligaments limit rotation of tibia during stifle joint flexion?

Answer 26

The cranial cruciate would hit and be stopped but the caudal ligament if joint tries to rotate.

Question 27

Cranial cruciate ligament rupture in dogs

Answer 27

Tested using cranial drawer test

Question 28

Ways to repair cranial cruciate rupture

Answer 28

1. extracapsular lateral suture (ECLS) stabilization
2. Tightrope procedure
3. Tibial plateau leveling osteotomy (TPLO)
4. Tibial tuberosity advancement (TTA)

Question 29

Dog Shoulder joint ligaments

Answer 29

Lacks typical collateral ligaments so uses muscles whose tendons cross the joint instead

1. Supraspinatus- act as Lateral collateral ligament
2. Infraspinatus- act as Lateral collateral ligament
3. Subscapularis- act as Medial collateral ligament
4. Coracobrachialis- act as Medial collateral ligament

Teres minor helps by restricting medial rotation of the shoulder & Teres major helps by restricting lateral rotation

Question 30

Dog elbow joint ligaments

Answer 30

1. Medial collateral ligament
2. Lateral collateral ligament
3. Oblique Ligament
4. Annular ligament
5. Olecranon ligament

Question 31

Dog stifle joint ligaments

Answer 31

1. Medial collateral ligament
2. Caudal cruciate ligament
3. Cranial cruciate ligament
4. Femoropatellar ligament
5. Meniscofemoral ligament
6. Lateral meniscus
7. Medial Meniscus
8. Patellar ligament
9. Fabella