Fractures Flashcards
How should you classify a fracture?
Open / closed Bone affected Position - articular, physeal, epiphyseal, diaphyseal Fracture line - transverse - oblique - spiral - comminuted - segmental Degree of displacement
When does direct fracture healing occur?
When fracture gap is less than 0.1mm
When does indirect bone healing occur?
Unstable fractures
When is casting / external coaptation indicated?
Small, young dogs and sometimes cats
Simple, stable, non-displaced, closed, diaphyseal fractures
Can only be used on the distal limb
Restricted finances
Need to be able to bandage a joint above and a joint below
What are the advantages of using intra-medullary pins?
Good at resisting bending - only indicated in stable fractures
Must only be used in the neutral axis
Relatively inexpensive
Can be combined with internal or external fixation
What are the disadvantages of intra-medullary pins?
Poor at resisting shear and rotational forces
Interferes with medullary blood supply
Placement is difficult in chondrodystrophic breeds
Can use a cerclage wire to provide compression to oblique fractures
What are the uses of positional screws?
Anchors the bone but does not change position
- maintains the relative position of two bone fragments
- fastens plate to bone
- anchor wire or suture to bone
- lock an inter-locking nail
What are lag screws used for?
Inducing compression between fracture fragments
- reconstruct the bone to take the load
What are the 3 ways you can apply a plate to perform a certain function?
Compression
Neutralisation
Buttress / bridging
When are external fixates indicated?
Long bone fractures Comminuted fractures Adjunct to an IM pin Open/infected fracture Immobilising joints for Arthrodesis Delayed unions Corrective osteotomies
What are the advantages of external fixation?
Rigid fixation with minimal invasion of injured area Allows access to open wounds Can maintain limb length Allow for gradually increasing loads Minimal complication rate Materials are inexpensive Cats are very tolerant
