Practical aspect of fracture management Flashcards
What are different fracture forces?
- Bending
- Bending and axial compression
- Axial compression
- Torsion
- High energy
- Avulsion - tibial tuberosity / lateral malleolus
-(fracture where tendon / ligament has torn the bone off)
What are the 3 main categories of fixing fractures?
- Plates + screws
- External skeletal fixators
- Pins + wires
What are different plates?
- Dynamic compression plates - need to be flush with bone
- Locking plates
- (Specialised plates)
What are advantages of locking systems?
- Excellent for use in poor quality bone - juvenile / osteopenic bone (hyperparathyroidism)
- Improved vascularity
- Less contouring
- Monocortical screws more stable
What are disadvantages of locking systems?
- Lag screws can’t be placed
- More expensive
- Cannot angle screws away from implants / fracture edge
What does a lag screw do?
- Pull bone together = compression
What are benefits of external fixators
- Can bridge joints
- cheaper than plates
- Can use for most things plates can do
What are important factors of placing external fixators?
- With a positive profile (thread wider than shaft) - thread needs to engage both cortexes
- With negative profile (thread same width as shaft) - thread shaft interface in medulla
What are advantages / disadvantages of intramedullary pin?
Advantages
* Good at resisting bending
-Strength in bending proportional to (radius)
* In neutral axis of bone
* Often relatively inexpensive
* May be used with other fixation devices (ESF, Plate)
Disadvantages
* Poor at resisting rotation
* Poor at resisting shear
* Interferes with medullary blood supply
* Difficult in chondrodystrophic dogs
What are uses of IM pins?
- Medium-long oblique simple fractures
- Must use with another fixation device = Plate, ESF, cerclage wire
What are different techniques of IM pin placing?
- Direct pinning = normograde - drill in from top of bone
- Indirect pinning = retrograde = in from fracture site to top of bone then drill back other way
Which bone can you not place an indirect IM pin in?
- Femur - will damage sciatic nerve at proximal end of femur
When would you use cerclage wire? disadvantages?
- With IM pin to secure long oblique fractures
- Disadvatages = can slip + can affect nerves - wrap around bone
What are the 4 A’s of fracture repair assessment? (radiographs)
- Apparatus
- Alignment
- Apposition
- Activity
Why is intergrity of fibula important with a tibial fracture?
- If fibula intact = can withstand compression + therefore can be bandaged + cast in young animals
