principles of fracture management Flashcards
what are orthoganal radiographs
two images taken at right angles to each other
how do you assess a fracture?
assign a fracture score and assess the forces that will be applied to the fracture, thining about how these can be managed
what does fracture score indicate?
gives an indication of the severity and biological nature of the fracture as well as non
biological factors such as owner finances and surgeon’s abilities
In most systems the higher the score the more demanding the fracture will
be to repair, the more robust that repair needs to be and the greater the chance
of complications
what patient factors need to be considered with fracture score?
Weight of animal:- heavier have a higher score
Age:- younger animals lower score
Boisterousness and ability to manage cage rest
Concurrent illnesses
what fracture factors need to be considered with fracture score?
Type of fracture:- does it allow compression plating or require external fixator, etc.
Open or closed?
Associated soft tissue injuries
Single or one of several fractures
what owner factors need to be considered with fracture score?
Will they comply with post-op instructions?
Finances
what surgeon factors need to be considered with fracture score?
Are they able to manage this fracture?
Is the correct equipment available?
what mechanical factors do you need to thing about when fracture scoring?
is there displacement/ comminution of the fracture
what biological factors do you need to thing about when fracture scoring?
young puppy should hear quickly but pathological farcture (Osteosarcomas) wont heal
what forces are applied to bones?
- Bending
- Torsion
- Tension
- Axial compression (when this force is applied on oblique fracture surfaces a shear force will be generated)
when thinking about plating a bone what do you need to think about regarding forces?
tension and compression
aspects of the long bone - plate needs to be placed on the tension side as will not fail due to tension
All diaphyseal bones are asymmetrically loaded when weight bearing
The mandible is also asymmetrically loaded during mastication
(By some fluke of nature the tension sides of the diaphyseal bones upon which
any plate will be placed are those with the easiest approaches )
where is the tension aspect of the femur?
lateral aspect
where is the tension aspect of the tibia?
medial aspect
where is the tension aspect of the radius?
craniomedial aspect
where is the tension aspect of the humerus?
latero-cranio aspect
where is the tension aspect of the mandible?
dorsal aspect
what is the impact of axial compression on a fracture?
Axial compression this is good if the fracture is transverse (i.e. at right angles to the long bone) or if the fracture interdigitates.
If not then compression of a comminuted (i.e. multiple fragments) or an oblique fracture causes the fracture to collapse or shear
what is the impact of tension on a fracture?
Tension produced by ligaments or tendons pulling on one of the bone fragments causes the fracture to be distracted and needs to be overcome with lag screwing or tension bands
what is the impact of torsion on a fracture?
Torsion resulting in rotation of the fracture site requires management with plates, external fixator or an interlocking nail
what is the impact of bending on a fracture?
Bending occurs due to the asymmetrical nature of the bone loading. A pin in the centre of the medullary cavity is best suited at counteracting this force
when does first intension (primary) bone healing occur?
Primary bone healing requires intimate contact of the bone ends preferably under compression.
This requires application of a bone plate and extensive dissection and manipulation of soft tissues
when does senond intension (secondary) bone healing occur?
Secondary bone healing does not require accurate reduction of the fracture
e.g. the application of an external fixator without manipulation of the fracture itself or adopting a look but do not touch approach (LBDT) or minimally invasive plate osteosynthesis (MIPO) when a plate is placed through subcutaneous tunnels
what is the purpose of fracture repair?
reduce movement and allow the formation of granulation tissue, callus and finally a bone
what is strain relating to a fracture
strain - the movement that occurs at the fracture site in realtion to the fracture gap
asmall gapwith large movement - greater strain
tissues will only tolerate a certain level of strain
