Dr. Pasquin? Anna?
WE WILL NOT BE TESTED ON ANY OF THIS.


Internal fixation of fractures:


Goals of fracture reduction in vet med:

provide reduction of fx to functional state
provide a stable repair to allow healing of reduced fx
provide as early and as close to normal function of the animal as 
possible, dogs won't stay in traction for 6 mos.
provide all of the above w/in the economic restraints/realities of 
veterinary medicine.

Initial management of fx patient

evaluate entire animal - most fx patients are in shock. pulmonary trauma, 
pneumothorax, contusions, diaphragmatic hernia, etc. abdominal 
trauma--hemorrhage, ruptured bladder. additional orthopedic trauma, 
neurological trauma. So, don't forget to look at WHOLE animal, even 
though there is an obvious broken bone.

Initial fx management

closed fx
below elbow and stifle - lateral splint
above elbow and stifle - cage rest
keep the fx closed to avoid infxn

open fx
clip and clean wound
splint if below elbow or stifle
may use local bandage if above elbow and stifle
never touch open fracture directly

[slide-cute dog in splint]

classification of fx
type
location
open vs closed
closed-no break in skin
open-bone exposed to environment
grade one
 small wound caused by penetration of bone fragment, usually minimal   
contamination, treat as if closed.
grade two
 larger wound, often caused by external trauma, variable soft tissue 
injury,   and contamination.
grade three
 severe degloving wound, marked skin/nerve/vessel destruction, major   
contamination, concern re: survival of bone/limb

biomechanically classified

low energy
 greenstick and fissure, spiral

high energy
 transverse, oblique, comminuted (more than two pieces), 
multiple(multiple segments)

complete - through whole bone
greenstick - not quite complete
fissure - longitudinal split, not all the way through.

configuration
transverse - across bone
oblique - an oblique cut
spiral- 360 degrees around the bone.

position

intra articular
diaphysis, metaphysis, epiphysis

displaced or nondisplaced
describe the distal fragment in relation to the top fragment.

fx management

rest and confinement has minimal application in vet med
external coaptation --best for fx below elbow and stifle
external fixation--becoming more and more popular
internal fixation--pins,screws,plates,etc

internal fixation

minimal animal and owner compliance needed
adaptable to most fx situations
provides good an early return to function
little followup needed.

BEFORE YOU OPERATE
make sure animal is stable. a fracture isn't an emergency. stabilize the 
patient and the fracture before surgery. don't try to operate when the 
animal is still in shock

get good rads, at least two views of the entire affected bone.

have at least two plans for repair. review rads, make sure you have 
necessary equipment, always prepare a graft site, anticipate problems 
before they occur, and if you aren't qualified, don't do it! refer out.

Orthopedic instrumentation-
proper instruments are essential
basic hand instruments - basic sx instruments, retractors, bone holding 
and reduction forceps and clamps, pin chuck, osteotomes and mallet, wire 
tightener, rongeurs and bone cutters, curettes.

[slide-handheld retractors]
[slide-periosteal elevator]
[slide-pin chuck w/key]
[slide-mallet]
[slide-rongeurs]
[slide-bone clamps]
 

power instruments - drill, saw, etc
must have power drill to put on plate. some folks go buy one from  
hardware store, but you can buy special ones that will go through the 
autoclave.
pin driver-comes in different sizes. comes w/drill, saw, pinchuck, etc - 
costs $8000.

Implants for internal fixation
intramedullary pins, orthopedic wire, bone screws, bone plates - all of 
which come in various sizes. pins can be smooth, grooved, ridged, 
partially or fully threaded....

ortho wire- spool wire: various gauges
A-O cerclage wire w/loop on it
various wire twisters available.

[slide-wire twister]
[slide-loop wire]
[slide-various wire tighteners]

bone screws - cortical, cancellous, malleolar

 used to put a plate on bone, used for interfragmentary compression of   
diaphyseal fragments, and as a lag screw for articular fragments.

bone plates - AO type
-there are a whole bunch of kind of plates which come in various sizes 
and shapes. Mostly, DCP = dynamic compression plate. Recently, LCP - 
limited contact plate - has been developed, but is very expensive.

[slide-DCPs]

There is no pattern to knowing what sizes they come in, btw. It's all 
metric units and there is no pattern.

plates are used as

tension band plate -- short oblique or transverse diaphyseal and 
metaphyseal fractures

buttress plate -- to span a highly comminuted fracture, also lengthening
various other ways to use plate, but she skimmed over them.

Intramedullary pins - slide shown - used often in distal femoral 
fracture.