Veterinary orthopaedic surgery

Question 1

What considerations would you make to manage initial trauma?

Answer 1

Any other injury?

Any haemorrhage?

Is the animal in shock?

Is the animal at risk of causing further injury?

Question 2

How can you prevent further contamination in open fractures?

Answer 2

Cover the wound and bone ends

Immobilise the fracture

Question 3

Once stable, what can be done during surgery for fractures?

Answer 3

Lavage

Debride

Surgical management if possible

Question 4

What are non-surgical options for fractures?

Answer 4

Most common for fractures below the elbow or stifle

Secondary/indirect healing

Often not the treat of option for athletic or working animals

Question 5

What are the advantages of external coaptation?

Answer 5

Preservation of blood supply and tissues

Quick procedure

Generally cheaper

Question 6

What are the disadvantages of external coaptation?

Answer 6

High maintenance

Higher risk of fracture disease

Cannot manage soft tissue wounds at the same time

Question 7

Describe a plaster of paris cast

Answer 7

Very heavy = uncomfortable

Should not get wet

Can disintegrate over time

Question 8

Describe a fibreglass resin cast

Answer 8

Lighter

Stronger

Water resistant -> durable

More expensive

Question 9

Describe casts in general

Answer 9

Include joint above and below

Ample padding +/- stirrups

Left in-situ for 4-6 weeks

May need replacing in growing animals

Question 10

What complications can occur with casts?

Answer 10

Fracture disease (joint stiffness, muscle atrophy, tissue adhesions, etc)

Joint laxity

Limb swelling

Pressure sores

Question 11

Describe splints

Answer 11

More common in small animal practice

Place over padding and conforming bandage

Covered with conforming and vet wrap

Similar complications as with casts

Question 12

Describe fibreglass splints

Answer 12

Thermoplastic material

Can be moulded directly to contour of patient

Lighter and stronger

Complications less likely

Question 13

Describe a robert jones bandage

Answer 13

Multiple layers of cotton wool/soft ban and conforming bandage

Top layer of vet wrap

Pulled tightly to immobilise fracture sites

Tend to be heavy -> care in proximal limb

Question 14

Describe conservative management (general)

Answer 14

Rest - crate or box rest

Pain relief

Comfortable bedding

Flooring with good traction

Supervision during toilet breaks +/- sling

Question 15

Describe surgical management

Answer 15

Allows minimal interfragmentary strain and a minimal fracture gap

Earlier return to exercise
-Compressive forces accelerate healing

Allows management of soft tissue injuries

Specialised procedures

Question 16

Describe external fixators (general)

Answer 16

Percutaneous pins/wires + rigid frame of clamps, bars and epoxy resin

Useful with multiple fracture fragments

Ilizarov or linear

Question 17

What are the advantages of external fixators? (general)

Answer 17

Early return to limb usage

Minimally invasive

Well tolerated

Management of soft tissue injury

Allow staged removal

Question 18

What are the disadvantages of external fixators? (general)

Answer 18

Cumbersome

Risk of infection at pin sites

Require expertise and planning

Question 19

Describe internal fixation (general)

Answer 19

Invasive surgery

Reduce fracture site and use hardware to maintain

Careful pre-surgical planning

Range of equipment depending on fracture

Question 20

Describe bone plates

Answer 20

Internal splints

Foxed to the bone using screws

Open and closed fractures
-Increased risk of infection with open

Question 21

Name different types of bone plates

Answer 21

Dynamic compression plate

Neutralisation plate

Buttress plate

Question 22

Describe a dynamic compression plate

Answer 22

Maximum contact between fragments as they are compressed together

Question 23

Describe a neutralisation plate

Answer 23

Neutralises forces

Shares the load between plate and bone

Question 24

Describe a buttress plate

Answer 24

When fracture cannot be reconstructed

Question 25

Describe lag screws

Answer 25

Cross fracture gap

Provides interfragmentary pressure

Question 26

When are position screws used?

Answer 26

When lag screws may cause interfragmentary collapse

Fracture fragments are too small

Question 27

Compare cortical and cancellous screws

Answer 27

Cortical

• Fixate both cortices
• Closer; more shallow thread
• Stronger

Cancellous screws

• Fixate cancellous bone
• Wider threads

Question 28

Compare self- and non-self-tapping screws

Answer 28

Self-tapping
-Creates it’s own thread as they are inserted

Standard
-Thread must be cute prior to screw being inserted

Question 29

Describe intramedullary pins

Answer 29

Sit within the medullary cavity

Good at resisting bending, NOT rotation or shearing

Can be used with interlocking nails to resist all forces
-Difficult as cannot see the holes!

Question 30

Describe cerclage wire

Answer 30

Wire wrapped around the bone

Compresses fragments together

Commonly combined with an IM pin

Question 31

Describe rush pins

Answer 31

Used in pairs

Cross over within medullary cavity

Commonly used for metaphyseal fractures

Useful in growing animals

Question 32

Describe kirschner wire

Answer 32

Hard wire

Temporary fracture fixation

Often used in combination with cerclage wire

Question 33

Describe the general rules of management of large animal fractures

Answer 33

Fractures of the carpus/tarsus and below are more amenable to repair

Muscle mass and body weight make it difficult to immobilise the proximal limb

Better results in young animals

Complications can occur in the contralateral limb

Question 34

Give two examples of large animal management techniques

Answer 34

Conservative management

Transfixation casting

Question 35

Describe conservative management (large animal)

Answer 35

Splint bone fractures

Scapular spine fractures

Question 36

Describe transfixation casting

Answer 36

Pins through an external cast

Takes the load away from the fracture site

Question 37

Describe external fixators (large animal)

Answer 37

Not very well tolerated

Some success seen in cows

Useful for horses for mandibular fractures

Question 38

Describe internal fixation (large animal)

Answer 38

Bone screws

• Metacarpal/metatarsal fractures
• PI and PII fractures

Dynamic compression plates

IM pins

Question 39

Describe amputations

Answer 39

Salvage procedure

Not performed in large animals

Can remove mid-bone or disarticulate the joint

Generally adapt very well

Long term overloading of contralateral limb

Question 40

Describe arthrodesis

Answer 40

Salvage procedure

Fusion or ankylosis of a joint by joint ossification

Immobilised the joint -> relieves pain

Can take several weeks

Common in lower-motion joints i.e. within the tarses

Question 41

Describe arthroplasty

Answer 41

Joint replacement

Only in small animal practice

Implant that attaches to bone at either side -> mimics joint

Hip and elbow +/- stifle

Question 42

What are toggle pins

Answer 42

Toggle sutures

Toggle two structures together

Can be used for hip luxation

Question 43

Describe arthroscopy

Answer 43

Diagnostic and therapeutic

Useful for:

• Debriding cartilage
• Curetting bone
• Removal of joint mice

Question 44

Describe joint flushes

Answer 44

Flushing sterile saline into a joint to lavage

Remove bacteria and debris

Small animal -> general anaesthesia

Horses -> general anaesthesia OR under standing sedation

Carried out for cases of joint sepsis,septic arthritis,etc

Question 45

Describe ligament prosthesis

Answer 45

Ligaments rarely surgically repaired

Use non-absorbable sutures to mimic

E.g. cranial cruciate ligament repair in small dogs

Question 46

What tools may be used for orthopaedic surgery?

Answer 46

Power drill and jacobs chuck

Various saws (oscillating)

• Power
• Hand

Retractors

Bone cutters (cut)

Bone tongeurs (nibble)

Osteotomes (slice)

Periosteal elevators