Orthopaedics: Practical Aspects of Fracture Management Flashcards
What are the different fracture forces?
- Bending
- Bending and axial compression
- Axial compression
- Torsion
- High energy
What is an avulsion fracture?
Where are two common places?
When a tendon or ligament breaks off a small peice of bone
Tibial tuberosity and Lateral malleolus
What are the three categories of implants?
- Plates and screws
- External skeletal fixators
- Pins and wires
What are the three different types of plates?
- Dynamic compression plates
- Locking plates
- Specialised
What are the three dynamic compression plates?
Neutral
Buttress
Compression
How do non locking plates provide stability?
Bone plate friction
Accurate contouring needed
How is stability generated with locking plates?
What are the advantages and disadvantages?
Fixed angle implants- interference between screw and plate
Adv
* Excellent for use in poor quality bone- juvenile, osteopenic
* Improved vascularity
* Less contouring
* Monocortical screws more stable
Dis
* Lag screws can’t be placed through the plate
* More expensive?
* Fixed angle systems cannot angle screws away from implants/fracture edges
How do positional and lag screws vary?
The way they are placed
Positional- holds plate
Lag- produced static interfragmental compression
What is external fixation made up of?
- Pins
- Connecting bars
- Clamps
- Frames
Which frame is type 1 and 2?
Left type 1
* Uniplanar, uni lateral
Right type 2
* Uniplanar, bilateral
What are the different intramedullar devices?
- Steinmann pin
- Rush pin
- Kirchner wire
- Kuntschner nail
- Interlocking nail
What are the advantages and disadvantages of IM pins?
Adv
* Good for resisting bending
* In neutral axis of bone
* Inexpensive
* Used with other fixation devices- ESF, plate
Dis
* Poor at resisting rotation
* Poor at resisting shear
* Interferes with medullary blood supply
* Difficult in chondrodystrophic dogs
When are IM pins used?
- Medium-long oblique simple fractures
- Interlocking mid diaphyseal transverse fractures
In combination with other technique for comminuted fractures
What is normograde and retrograde IM pinning?
What decides pin length and width?
Normograde- direct pinning
Retrograde- indirect pinning
Width- as large as possible, 30% diameter if combining with plate or ESF
Length- radiographic intact controlateral bone
When is cerclage wire used?
- Used in combination with IM pins for long oblique fractures
- Must be tight to provide compression- primary bone union
- Can slip along diaphysis- can groove
How is the knot of cerclage wire tied?
