Orthopaedics: Assessment of Fracture, Fracture Healing and Orthoexamination

Question 1

When should you see a horse with a suspected fracture?

Answer 1

Straight away

Potential for serious injury
Early recognition of seriousness
Small wounds on distal limbs often more serious then large proximal

Question 2

What needs to be assessed with a suspected fracture patient?

What are the objectives of the examination?

Answer 2

Acutely lame/NMB

Evidence of external trauma

Objective examination- determine specific injury, systemic evaluation

Objectives-
Is it safe to examine
Determine specific injury- location, type, weight bare
Options
systemic evaluation- pain, shock
other factors- police, legal, temperament/size of the animal

Question 3

What needs to be considered initially for a horse with a potential fracture?

Answer 3

Airway, breathing and circulation
Shock therapy and venous access
IVFT- crystalloids- 60-90ml/kg/kr

Analgesia- opioids, NSAIDs

Antibiotics- open fracture

Oxygen

Question 4

What does conservative v surgery v euthanasia depend on?

Answer 4

Type

Presence of complicating factors

Economics

Expertise and equipment available

Welfare/ethics

Question 5

What equine fractures require immediate humane destruction?

Answer 5

Complete fracture of femur

Complete fracture of humerus

Complete tibia fracture

Comminuted open

Economic reasons

Question 6

Following stabilisation and before transport to hospital what needs to be discussed with owner?

Answer 6

Prognosis- athletic function, salvage

Financial implications- short term, long term

Question 7

What are the basic principles for stabilisation of fractures and splinting?

Answer 7

• Stablise joint above and below
• Always extend to top of long bone- never end in middle
• Do not end splint at the fracture site
• Bandaging- each successive later tighter to conform more than last- primary secondary. tertiary
• Splint- aim to stabilise the fracture/subluxation, prevent displacement and protect soft tissues
• Materials for splinting- guttering, wood/broomstick

Question 8

How should equine fracture cases be transported?

Answer 8

Load as atraumatically as possible- bring trailor close to horse

Loosely tie the patient- allow for use of head and neck for balance, narrow confinement

Forelimb- travel with horse backwards
Hindlimb- travel with horse forwards

Question 9

What is the done with initial presentation of small animals?

Answer 9

Airway, breathing and circulation

Shock therapy and venous access- IVFT, analgesia, antibiotics, oxygen

Thoracic radiograph- pneumothorax, haemothorax, diaphragm rupture
bladder

Secondary assessment- open wounds/fractures

Consider- financial, expertise, equipment, timings

Question 10

What are the classifications for open fractures?

How should an open fracture initially be managed?

Answer 10

Grade 1- bone punctures through the skin and retracted back beneath skin
Grade 2- exposure of the bone with soft tissue damage >1cm
Grade 3- high energy trauma, extensive soft tissue damage, loss of soft tissues and often high contamination

Debridement-
Gross
Lavage- 18G needle 20ml syringe- saline
Sharp dissection
Wet to dry dressings
Silver dressings

Initial fracture stabilisation

Question 11

How are fractures fixed?

Answer 11

External coaptation

IM devices

Plates and screws

External fixation

Question 12

What is a fracture?

Answer 12

Disruption in the cortical continuity of a bone, complete or incomplete

Question 13

What are the forces on a fracture?

Answer 13

Bending

Torsion

Compression

Tension

Shearing

Question 14

What is an intrinsic fracture and what causes them?

Answer 14

Pathological fractures

Local disease- neoplasia, incomplete healing

Systemic disease- osteopenia, hyperparathyroidism

Question 15

How are fractures classified?

Answer 15

Open/closed-
Grade I, II, III

Bone

Position- articular, epiphyseal, growth plate, diaphyseal

Fracture line- transverse, oblique, spiral, segumental

Degree of displacement

Reconstrucable

Question 16

What is the fracture healing-vascular response?

Answer 16

Normal blood supply to bone-
Nutient, periosteal and D/P metaphyseal arteries

Blood supply to fractured bone-
+extraosseous arteries
from tissues around the fracture
can be distrubred by fixation
Grade III- less blood supply- don’t damage

Question 17

What are the different primary bone healings?

What is fracture assessment score?

Answer 17

Contact-
complete contact between bones- space less then 0.01mm
will take longer to heal but no callus

Gap- more then 1mm
Callus
Rapid bone healing
Because there is a haematoma, fibroblasts- callus formed

Based on mechanical, biological and clinical assessment- higher the number better the prognosis

Question 18

What are the positive and negative fracture healing factors?

Answer 18

Postive-
young, healthy, low energy, single injury, closed reduction, non-articular

Negative-
old, systemic/local disease, high energy, open, multi-trauma, open reduction articular

Question 19

What are fracture healing complications?

Answer 19

Failure of fracture to heal in time/manner expected

Infection

Instability

Implant failure

Vascular compromise

Nearly always due to poor surgical technique- fracture healing is a race between bone repair and implant failure

Question 20

What are the different implants and when are they used?

Answer 20

• IM pin alone- never
• IM pin and cerclage wire- long oblique or spiral fractures
• IM pin and external fixators- many diaphyseal and metaphyseal fractures
• Rush pins- metaphyseal, physeal and epiphyseal
• Tension band fixation- avulsion fractures
• Interlocking nail- most diaphyseal fractures
• External fixator- most diaphyseal and metaphyseal fractures
• Circular fixaror- most
• Bone plate- most
• Bone plate and rod- buttress fracture repair

Question 21

What are the advantages and disadvantages to an IM pin?

What is the technique?

Answer 21

Adv-
good at resisting bending
In the neutral axis of the bone
Often inexpensive
It May be used with other fixation devices

Disadv-
Poor at resisting rotation and shear
Interferes with medullary blood supply
Difficult in chondrodystrophic dogs

Technique-
direct/indirect pinning
Choose correct size/width

Question 22

What is cerclage wire?

Answer 22

Used in combination with IM pins for long oblique fractures

Must be tight to provide compression- primary bone union

Can slip along diaphysis- causes vascular damage

Question 23

What are screws for?

What are the two types of screws?

When are they used?

Answer 23

Used to keep plate against the bone

Positional and Lag

Positional- to maintain the relative position of two bone fragments, to hold a plate to bone, to anchor wire or suture bone

Lag screw- way a screw is placed
produced static infragmental compression- the most efficient way of compression

Question 24

Describe how to place a lag screw

Answer 24

1. Over drill cis cortex
2. Place drill insert and drill trans cortex
3. Measure depth
4. Tap (trans cortex only)
5. Insert screw
6. hole in first part the width of the screw, second half tapped and when tightened pulls together with heads

Question 25

What do bone plates do?

What are the different types?

What is a DCP plate?

Answer 25

Remove all forces placed on a fracture

Compression-load sharing
Neutralisation- protection of other implants
Bridging- no load sharing

DCP plate- as plate tightens pulls towards and compresses fracture

Question 26

How do external skeletal fixators work?

What are the advantages and disadvantages?

Answer 26

• Pins are placed within bone which span the fracture
• Pins are connected by a thick connecting bar
• external scaffold
• Can transverse joints to stop motion

Advantages-
Negates all fracture forces
Rigid fixation with minimal invasion of injured area
Allows access to open wounds during fracture repair
Can maintain limb length, if bone defects exist, while secondary bone healing occurs
Allows for gradual increasing of loads to be applied
Materials in expensive

Disadvantages-
High complication rate- iatrogenic interference, catches on clothing, infections
Can weaken/losen over time

Question 27

What are the main principles of articular fractures?

Answer 27

Common

Require primary bone healing- accurate reduction, require rigid fixation

Early return to full function-
Phyisotherapy
Range of motion
Avoid atrophy of joint tissues

Question 28

What are avulsion fractures?

What is salter harris classification?

Answer 28

Avulsion fractures-
associated with strong avulsion force at a muscle/tendon/ligament attachment to bone
Tibial tuberosity- quads, lateral malleolus- lateral collateral ligament

Salter harris classification- juvenile animals, includes part of all the physis