Orthopaedics

Question 1

What are the signs of unilateral forelimb lameness?

Answer 1

Head nods down when sound limb lands

Question 2

What are the signs of unilateral hindlimb lameness?

Answer 2

Increased excursion of gluteal region on lame side, toe-dragging (reluctant to flex hocks) + medial swinging of affected limbs

Question 3

List features of lameness.

Answer 3

Shortened stride length of lame limb
Increased fetlock extension (dropping) on sounder limb
Sound foot may make louder noise on landing

Question 4

Explain the grading of lameness

Answer 4

0 = sound
1 = subtle head nod/gluteal movement (not every stride?)
2 = obvious consistent head nod/gluteal movement
3 = pronounced head nod/gluteal movement
4 = horse so lame can barely trot
5 = non-weight bearing

Question 5

How much does the equine hoof grow per year?

Answer 5

7-10mm per month

Question 6

What are the aims of shoeing?

Answer 6

Protect hoof wall against wear + tear
Improve performance
Additional support on slippery surfaces
BUT: add weight so affect foot flight, restrict expansion during landing, cause problems when incorrect

Question 7

What is the cause of navicular disease?

Answer 7

Clinical manifestation of pain from navicular bode/distal sesamoid/navicular bursa and other associated structures

Unknown aetiology, possibly:

1. VASCULAR: arteries occlude - necrosis - bone resorption
2. BIOMECHANICAL: flat foot with long toe/low heel - increased pressure between DDFT + navic bone - remodelling + inflam of navic bone - surface defects (PAIN)

Question 8

What are the clinical signs of navicular disease?

Answer 8

Insidious onset:

frequent stumbles, reluctant to work on circle, toe pointing @ rest, bilat. lameness- accentuated on hard circle

Question 9

How is navicular disease diagnosed?

Answer 9

Nerve blocks: +ve to palmar digital, distal interphalangeal, navicular bursal
Rads: cyst lesions in medulla, medullary sclerosis, reduced corticomedullary demarcation, new bone on flexor surface
Nuclear scintigraphy: increased uptake at navicular bone

Question 10

List the treatment options for navicular disease.

Answer 10

Medical- NSAIDS, vasodilation, steroids, tiludronate
Surgical: desmotomy of SL, decompress navicular medullary cavity, neurectomy
Foot care

Question 11

What are the clinical sins of hood abscesses?

Answer 11

Increased digital pulse, and ACUTE lameness

Question 12

What are corns and how are they caused?

Answer 12

Bruise of sole between bars + hoof wall. Due to pressure from heel of shoe if left on too long, too short or foot imbalance.

Question 13

List emergency foot presentations.

Answer 13

Puncture wounds of sole
Coronary band laceration
Heel bulb laceration
Hoof wall avulsion

Question 14

Describe the aetiology, diagnosis and treatment of seedy toe.

Answer 14

Bacteria and fungi produce separation of the white line- doesn’t produce any clinical signs. If advanced can can instability of pedal bone and infection of sensitive laminae.
DIAGNOSIS: hollow sound when hoof capsule percussed
TREATMENT: pare regions of abnormal horn and pack with iodine/metronidazol. Is severe - bar shoe to stabilise hoof

Question 15

What are keratomas?

Answer 15

Benign hyperplastic keratin masses originating from epidermal keratin-producing cells at any point in wall/sole causing space-occupying tumours which disrupt hoof architecture allowing bacterial infection and recurrent abscesses.

Question 16

What is the causative agent of thrush?

Answer 16

Fusobacterium necrophorum - infects frog in wet conditions

Question 17

What ate the clinical signs of thrush?

Answer 17

Black sticky discharge
Terrible smell
Underrun sole
Limb oedema

Question 18

What is septic pedal osteitis?

Answer 18

Penetrating injury to the sole involving P3- causes cjrpnic sub-solar abscesses.

Question 19

What is canker?

Answer 19

Chronic proliferative pododermatitis of the frog- may extend to undermine sole and heels.

Question 20

What is quittor?

Answer 20

‘Collateral cartilage infection’

Question 21

How are wounds debrided?

Answer 21

Hydrodynamic lavage with isotonic fluid or dilute iodine/chlorhexidine or a sharp blade.

Question 22

List potential wound complications.

Answer 22

Hypergranulation (‘proud flesh’)
Hoof wall/coronary band wounds
Sequestrum formation
Tendon laceration

Question 23

Describe the predilection sites for proud flesh.

Answer 23

Distal limbs and over joints (where increased skin movement and reduced vascularity), horses > ponies

Question 24

What is a sequestrum?

Answer 24

Dead fragment of bone associated with infection- resulting in ‘involucrum’- surrounding reactive bone and constant recurrent discharge from the tract.

Question 25

Which scenarios indicate a hopeless prognosis for an equine fracture?

Answer 25

Complete fracture of radius/humerus if horse >300kg
Complete fracture of femur/tibia in adults
Long bone fractures with severe soft tissue injuries
Severely contaminated fractures

Question 26

How should a horse with a suspected fracture be transported?

Answer 26

Forelimb fracture - facing backwards (wt on hindlimbs during braking)
Hindlimb fracture - facing forwards (wt on forelimbs during braking)

Question 27

What is the cause of orthopaedic infections?

Answer 27

Direct contamination (penetrating wound)
Idiopathic inoculation (intra-articular injury/medication)
NEONATES: haematogenous spread

Question 28

What are the common causative agents of orthopaedic infections?

Answer 28

Gram +ve organisms e.g. S. aureus

Question 29

How are orthopaedic infections diagnosed?

Answer 29

Clinical exam- synovial distension
Synovial fluid leaking from joint
Rads
Synovial fluid analysis

Question 30

How are orthopaedic infections treated?

Answer 30

Synovial lavage: large volumes- 5-30ml, arthoscopy
Systemic antimicrobials: gentamicin + penicillin
Intra-articular medication
Regional limb perfusion: apply tourniquet, IV a/bs, repeat every 2 days
A/b impregnated sponges
NSAIDs

Question 31

What are the clinical signs of neonatal orthopaedic infection?

Answer 31

Affects multiple joints including physes.
Epiphyseal infection: hot, swollen joints
Physeal infection: subtle swellings, severe lameness, recumbency