Lecture 26 - LA Fracture Repair Flashcards
Fractures that are not appropriately coapted can result in what 5 things?
- Closed fractures becoming open
- Hairline fracture lines turning into comminuted, catastrophic fractures
- Eburnation of bone edges
- Lack of preservation of blood supply
- Increased pain and anxiety for the patient
When coapting, where should the fixation method never be ended?
In the middle of a long bone/diaphysis
Why should the fixation method never be ended in the middle of a long bone?
Creates stress point and bending force that can lead to fracture;
Want to stabilize one joint above and one below the fracture
Stability occurs on ___ planes.
2
What are the types of coaptation?
PCV splints, cast material, pre-made splints, wood
What are advantages to LA orthopedics?
- Ruminants easily callus
- Some fractures are amenable to standing repair
- Some fractures will heal conservatively
- Neonates will heal due to growing mode of bone, good vascularity, and smaller weight
What are disadvantages of LA orthopedics?
- Weight
- Athletic career
- Strength of muscles (difficult to reduce fracture bc of strength of muscles that need to be counteracted in sx)
- Cost
What are the 4 most commonly used fixation methods in LA?
- Cast/External coaptation
- Transfixation pin cast
- Lag screw fixation
- Bone plate internal fixation (locking and non-locking)
What 4 methods of fracture stabilization are not applied in LA but can be used in select cases for young, smaller animals?
- External skeletal fixator
- Intramedullary pin
- Interlocking nail
- Cerclage wire/tension band
T/F: Cast management alone is inadequate in equines
True
What LA spp do casts have a strong use in?
Bovine and small ruminants
What is this?
Thomas Schroeder splint
A transfixation pin cast is a hybrind bt a _____ and an _____.
cast, external skeletal fixator
How many Steinmann pins are inserted above the fx site in a transfixation pin cast?
2-4
What does a transfixation cast allow for?
Allows biomechanical forces from the weight of the animal to be transferred from the pins in the bone into the cast
What are a couple of complications that can result from a transfixation pin cast?
- Pin ring-sequestration –> loosening and pain
- Fx of bone through the pin-bone interface
What are 4 uses for a trans`fixation pin cast?
- Increasing stability of external coaptation yet remaining economical
- Stabilization of complicated locations
- Comminuted fractures that are not reconstructable
- Open fractures where implants at the fracture site are contra-indicated
What is lag screw fixation?
Method of placing a cortical bone screw such that it compresses the two “sides” of bone it interfaces
What type of bone healing do lag screws promote?
Primary
What are the two types of holes drilled for a lag screw and which is larger?
Glide hole (larger)
Thread hole
What is the strongest method of fixation available?
bone plate fixation
In adult horses and larger long bones (cannon, tibia, radius), what type of fixation/what degree is mandatory?
Double plate fixation at 90 degrees
What are the two global types of bone plates?
Traditional (limited contact - dynamic compression)
Novel (locking compression)
What two fixation methods are used in the management of jaw fractures?
External fixator and cerclage wire to create “braces”
What is a huge complication in recovery from orthopedic surgery in LA?
The animal wakes up, freaks out, and bends/breaks the implants/further fractures the bone after a long and difficult surgery
What can be done to minimize recovery complications in fracture repair?
Standing fracture repair and standing implant removal
What is implant failure a result of?
Lack of stability in the original repaid
What is the biggest disappointment in LA ortho surgery?
infection
What fractures are at higher risk for infection?
Open fractures
What do bacteria create on the surface of implants?
biofilm
What can occur in horses if instability after a repair is present?
Animal will be painful –> non-weight bearing –> overload of contralateral limb –> contralateral limb can develop laminitis
