Diagnostics Equine Musculoskeletal (Renate)

Question 1

Waht are the big 7 in orthopaedic disease complexes in horses?

Answer 1

1. OA
2. OCD
3. Fx (fatigue or impact)
4. Tendonitis
5. Navicular dz
6. Wounds
7. Laminitis

Question 2

Why are some iaging modalitis chosen over others in horse?

Answer 2

Need for GA - 1% death risk for hroses is a big deal!

Question 3

What type of image do radiographs produce?

Answer 3

“summation image”

Question 4

Other names for OA

Answer 4

• arthrosis, DJD

Question 5

What are osteophytes? What similar structures are seen elsewhere?

Answer 5

> New bone fomation along the ‘lip’ edges of articular surface (trying to stabilise the joint)
Inthesiophytes = new bone formation at attachement of a soft tissue structure

Question 6

Can cartilage be seen on rads?

Answer 6

NO - just see narrowed/widened join space

Question 7

What is high ringbone?

Answer 7

OA of the pastern joint -> MINIMAL synovial response, straight to swelling d/t palpable bony changes above the coronary band

Question 8

Outline the stages of pathogeneis assocaited with OA

Answer 8

1. joint effusion (bog spavin in the hock)
   - excessive synovial fluid d/t irritation and inflammatio nof the synovial membrane
2. cartilage damage
3. boney damage

Question 9

How do horses IVDs differ to smallies?

Answer 9

No nucleus pulposus (only fibrous tissue) so dont get disk problems

Question 10

How are the 3 main stages of damage associated with OA visable on rads?

Answer 10

1. joint effusion and osteophytes
2. articular artilage: narrowed joint space
3. subchondral bone: sclerosis/lucency (lucency worse prognostically as body given up -> lysis)

Question 11

Wht may narrowing of the joint eventually lead to?

Answer 11

Ankylosis

Question 12

What is surgical ankylosis termed? How is this performed?

Answer 12

Arthrodesis

• chemical/physical destruction of cartilage
• only possible in low motion joints eg. DIT and IT joints mainly for shock absorption not movement

Question 13

What is bone spavin?

Answer 13

OA of the DIT and IT joints -> ankylosis

Question 14

Gol standard diagnostic method for OA?

Answer 14

MRI

Question 15

What is prognosis and tx after dx based on?

Answer 15

> structures affected (high v low motion joints)
type of disease (1/2, traumatic, devlopmental)
advanced disease? (early v late stage)

Question 16

How does inflamed synovial fluid appear cf. healthy?

Answer 16

decreased viscosity (MORE watery!!!)

Question 17

What are corns?

Answer 17

Inflammation of a specific area of hoof wall (dx with hoof testers and hoof knife, easy - shouldnt get to referral stage to be dx wih corns!)

Question 18

Tx stategies for OA?

Answer 18

• strategic analgesia
• joint supplements
• novel tx concepts
• salvage procedures
• excercise modification/physio

Question 19

What cause the changes in synovial fluid composition when inflamed?

Answer 19

• PGE2 and MMPs: V proteoglycans, ^ water and ^ collagen breakdown
• IL1 and TNFa
• PG, LT, free radicals and neuropeptides

Question 20

Where do steroids and NSAIDs act?

Answer 20

> steroids PLA2
- cell membrane phospholipid -> arachadonic acid stage
NSAIDs COX
- arachadonic acid -> PGs and Thromboxanes
- 5-lipoxygenase pathway -> leukotrienes
pain,swelling and cartilage degradation, heat (inflammation)

Question 21

Prevention of OA?

Answer 21

• v BCS
• shoeing and correct foot shape
• other things…

Question 22

Look up aetiology/pathogenesis, clinical signs, imaging signs, Dxx, Dx, Prog and Tx of all the big 7

Answer 22

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Question 23

Most common site of lameness in the horse?

Answer 23

• foot (difficult to relate pain o secific structures by direct visualisation, palpation or manipuplation)