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Flashcards in Fracture management 2 Deck (55)
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1

Explain non-locking plate contouring

- Required to create bone-plate friction
- Contour plate to the shape of the bone
- Use bending iron or press

2

Explain the use of dynamic compression plates

- Apply axial compression to transverse fracture
- Aim for primary bone union (contact healing)

3

Explain the use of compression screws in plates

- Screw either side of fracture fixed
- Screw inserted eccentrically
- As tightened, head shift down towards centre, pulls bone with it towards the fracture therefore compressing the fracture site
- Compression screws placed first, then neutralisation screws placed (place one positional first to hold plate in place

4

Explain the use of neutral screws in plates

- As tightened pull plate onto bone
- Do not move in plate hole and do not move bone

5

How many screw head movements and how many compression screws can be use in plates?

- Maximum of 2 screw head movements per plate hole
- Maximum of 2 compression screws, rest all neutral screws

6

Explain the function of neutralisation plates

- Used where other implants are used to reconstruct the fracture e.g. K wire, cerclage wire
- Used to stabilise against (neutralise) some forces and allow weight bearing on bone
- Bone takes some load

7

Explain the function of bridging plates

- Used where fracture is not reconstructed and bone unable to take any load, unstable to all forces
- Plate must take load, spans the fracture gap
- Use larger plate and auxillary fixation device e.g. IM pin

8

What is the main risk with bridging plates?

Plate failure in particular in mid section

9

What are the advantages and disadvantages of plate application for fracture repair?

- Good for fracture reduction/internal fixation
- But requires dissection and high biological cost: trauma to bone, disruption to soft tissue attachment and blood supply

10

Explain the use of locking plates

- Screw head locks into plate, have thread on head of screw and plate
- Implant stability provided by locking mechanism

11

Outline the advantages of locking plates

- Implant stability not dependent on bone quality
- Good purchase in poor quality bone
- Does not compress plate onto bone so no periosteal vascular disturbance
- Exact contouring not necessary
- Able to resist higher loads
- No chance of screw/thread stripping

12

Explain how plate failure most common occurs

- Exposure to cyclical bending due to trans cortex not being in tact (trans cortex must resist bending)
- Non-reconstructed fractures higher chance of bending
- Most common fail through screw hole

13

What is an external skeletal fixator device?

A device that fixes bone using pins inserted into the bone, external to skin and bone

14

Name the different frame times for ESFs

- Linear (most common)
- Circular
- Free form (putty/epoxy)
- Hybrid

15

Describe linear ESFs

- Longitudinal connecting bars
- Clamps attaching to pins inserted into bone
- Versatile
- Limited surgical incision so low biological cost

16

Name the different types of linear ESFs (5) in order from weakest to strongest

- Type IA
- Type IB
- Type II modified (IIB)
- Type II (IIA)
- Type III

17

Describe type IA linear ESFs (structure, insertion, pins, risks)

- Uniplanar and unilateral
- Safe corridor insertion through clean skin site
- Do not exceed 30% of bone diameter
- Plain and threaded pins used
- Tip threads and positive threads prevent breakage due to bending
- Pin tract infection risk

18

Describe type IB linear ESFs (structure, insertion, pins, risks)

- Biplanar (craniocaudal and mediolateral plane) and unilateral (one side of each plane)
- SAfe corridor insertion through clean skin site
- Do not exceed 30% of bone diameter
- Plain and threaded pins used, tip threads and positive threads prevent breakage due to bending
- Consideration of pin tract infection

19

Describe type IIB linear ESFs (structure, pins)

- Uniplanar, bilateral (2 sides of bone)
- Full pins top and bottom, half pins in between

20

Describe type IIA linear ESFs (structure, pins, risks)

- Bilateral and uniplanar
- Full pins throughout
- Technically difficult

21

Describe type III linear ESFs (structure, disadvantages)

- Biplanar, bilateral
- Excessively complicated, large, rarely used

22

Describe the structure of circular ESFs

Thin wires suspended by rings surrounding the limb

23

Outline the advantages and disadvatages of circular ESFs

- More versatile
- More applications
- Good for complex fracture applications

- More complex
- More demanding

24

Outline the advantages and disadvantages of free form/epoxy putty ESFs

- Very adaptable, bespoke frame
- Clamps and bars replaced by resin or epoxy putty

- Messy, cannot adjust post-op, tricky to de-stage

25

Describe hybrid ESFs and give a common example

- Combination of various fixator types
- Typically circular ESF distally + linear ESF proximally

26

Compare the healing achieved with ESFs and bone plates

- Bone plates have slower healing, primary bone union
- ESFs use secondary bone healing and heal twice as quickly, used for non-reconstructable/comminuted fracture

27

Describe the basic application of ESFs

- Pins designed for purpose, can have negative and positive profile
- 2 placed at either end of bone, external connecting bar placed
- Pins clamped in position whilst examining limb for length and orientation of the two joints
- Further pins placed to strengthen the construct with 2 close to the fracture
- Some limited ability to alter alignment after pins placed

28

Outline the main disadvantages of ESFs

- Do not get accurate fracture reduction
- Pins loosen
- Pin tract discharge common
- Complications almost guaranteed due to catching of structure
- Frequently have problems with bone healing due to technique or pin loosening
- Avoid ESF where possible as internal more reliable

29

In what conditions are splints required?

- Unstable fractures
- Unstable tendon injuries

30

When an injury is in region 1 of an equine limb, describe the correct splint placement

- Need to align the dorsal cortices
- Place splint dorsally
- Use commercial splints