Orthopaedics: Assessment of Fracture, Fracture Healing and Orthoexamination Flashcards
When should you see a horse with a suspected fracture?
Straight away
Potential for serious injury
Early recognition of seriousness
Small wounds on distal limbs often more serious then large proximal
What needs to be assessed with a suspected fracture patient?
What are the objectives of the examination?
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
What needs to be considered initially for a horse with a potential fracture?
Airway, breathing and circulation
Shock therapy and venous access
IVFT- crystalloids- 60-90ml/kg/kr
Analgesia- opioids, NSAIDs
Antibiotics- open fracture
Oxygen
What does conservative v surgery v euthanasia depend on?
Type
Presence of complicating factors
Economics
Expertise and equipment available
Welfare/ethics
What equine fractures require immediate humane destruction?
Complete fracture of femur
Complete fracture of humerus
Complete tibia fracture
Comminuted open
Economic reasons
Following stabilisation and before transport to hospital what needs to be discussed with owner?
Prognosis- athletic function, salvage
Financial implications- short term, long term
What are the basic principles for stabilisation of fractures and splinting?
- 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
How should equine fracture cases be transported?
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
What is the done with initial presentation of small animals?
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
What are the classifications for open fractures?
How should an open fracture initially be managed?
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
How are fractures fixed?
External coaptation
IM devices
Plates and screws
External fixation
What is a fracture?
Disruption in the cortical continuity of a bone, complete or incomplete
What are the forces on a fracture?
Bending
Torsion
Compression
Tension
Shearing
What is an intrinsic fracture and what causes them?
Pathological fractures
Local disease- neoplasia, incomplete healing
Systemic disease- osteopenia, hyperparathyroidism
How are fractures classified?
Open/closed-
Grade I, II, III
Bone
Position- articular, epiphyseal, growth plate, diaphyseal
Fracture line- transverse, oblique, spiral, segumental
Degree of displacement
Reconstrucable
What is the fracture healing-vascular response?
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
What are the different primary bone healings?
What is fracture assessment score?
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
What are the positive and negative fracture healing factors?
Postive-
young, healthy, low energy, single injury, closed reduction, non-articular
Negative-
old, systemic/local disease, high energy, open, multi-trauma, open reduction articular
What are fracture healing complications?
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
What are the different implants and when are they used?
- 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
What are the advantages and disadvantages to an IM pin?
What is the technique?
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
What is cerclage wire?
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
What are screws for?
What are the two types of screws?
When are they used?
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
Describe how to place a lag screw
- Over drill cis cortex
- Place drill insert and drill trans cortex
- Measure depth
- Tap (trans cortex only)
- Insert screw
- hole in first part the width of the screw, second half tapped and when tightened pulls together with heads
What do bone plates do?
What are the different types?
What is a DCP plate?
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
How do external skeletal fixators work?
What are the advantages and disadvantages?
- 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
What are the main principles of articular fractures?
Common
Require primary bone healing- accurate reduction, require rigid fixation
Early return to full function-
Phyisotherapy
Range of motion
Avoid atrophy of joint tissues
What are avulsion fractures?
What is salter harris classification?
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
