Small Ani. Sx- Orthopedics- Fracture Tx- Options of Tx 1

drraythe's version from 2016-04-29 14:41


Question Answer
Two main broad categories of choices of treatment?(1) conservative treatment (box confinement, splint/cast) (2) Surgical treatment
in what 4 situations would you choose to conservatively treat with box (cage) confinement?(1) Some pelvic fractures (2) Scapular fractures (flat bones surrounded by mm) (3) Pathological fractures (dont bother trying to stabilize fx, they wont heal bc due to underlying prob like osteosarc) (4) Very young patients (< 3 months of age) (their bone is too soft, there wont be any support)
most common tumor to cause bone fx?osteosarc
what two things must you do if you are going to tx conservatively with box confinement?PAIN management and leash walking
3 indications for casts/splints?(1) Closed fractures below elbow/knee (2) Closed reduction possible (3) Young, fast healing patients (old patients take too long to heal, there is loss of movement in joint for too long, leads to ankylosis and severe mm atrophy)
what are two kinds of fractures which are ok to use a splint/cast on?(1) Greenstick fracture (2) Simple transverse fractures (bc once you reduce them, they are stable)
what are some common materials you'd need to make a splint?Metal /plastic /fiberglass spoon splint, Cast padding (need padded inside to avoid ulcers) Adhesive tape, Elastic tape or vetrap, Tongue depressors (stirrups)
splints are less stable than casts-- in what situations are they useful? (2). What locations are they useful in? (3)GOOD FOR: Temporal fracture stabilization (pre-op stabalization), Ancillary support (after sx you wanna give more support). You can tx Metacarpus, Metatarsus, digits with splints (tibia, radius, ulna need casts tho)
Why should the animal be in deep anesthesia for placing a cast? How dry should the leg be? Should you clip the hair?Need to be deep under because you will be reducing the fx to fix it and that will be super painful. Make sure leg is dry, and it is better if you DONT clip the hair
which fracture should you NEVER use a cast with, why?never an open fx, it will end in amputation
do you put on fiberglass for cast prox to distal or distal to prox? Do you go laterally or medially? how much overlap?Distal to prox, medially. 50% overlap.
how do you make sure you can monitor swelling within the cast to prevent big problems? When do you know to change the cast bc swelling complications?digit 2 and 3 must be visible out of the bottom of the cast so you can monitor swelling. If digits go apart, change the cast!
once you wet the casting material, it is activated and starts to harden. How do you handle it from this point out?use your PALMS bc fingers might indent too much--> pressure necrosis.
after you placed the cast, what 2 things should you do?(1) rads (2) Hospitalization 24 h
how often should you change the cast? how often should you take radiographs to check it?Changes every 1-2 weeks (more if growing animal or the cast gets wet or otherwise compromised). Radiographs every 1-2 weeks
how might you be able to repurpose a cast?clean it up again and it can be used as a splint
why can't you go over the elbow or stifle with a cast?need to stabilize prox and distal to joint-- but a cast can't stabilize rotational forces
why can't a cast get wet?damages the skin under it

Sx: Nails and Pins

Question Answer
5 things used for surgical fracture treatment? (read over)Nails & Pins, Orthopedic wire, External fixator, Screws and plates, Internal fixator
whats the diff between K-wire & Steinmann pins?K-wire: < 2mm. Steinmann pins: 2-5mm
Intramedullary Pinning is used for what kinda fx?DIAPHYSEAL FX
why does this pic of an intramedullary pin has cerclage wire with it?need to combine IM pin with another implant (in this case cerclage wire) to neutralize forces-- bc IM pin alone is not super stable (thus why it is really only good with diaphyseal fx)
which forces does and doesn't an intramedullary pin protect against?DOES protect against bending and shearing, doesnt protect against rotational or axial stability
what are three options for things you use in combination with intramedullary pins?(1) Cerclage wires (a- neutralize rotation) (2) External fixator (b-one pin prox and distal neutralize rotation) (3) Plates (c- neutralizes compression and rotation and protects pin from bending)
how much of the medullary cavity should be taken up by the intramedullary pin?60-70% of medullar cavity
what instruments do you need to put in an intramedullary pin?Jacobs chuck (to insert pins), Cutting pliers (to cut wire to desired length)
Insertion technique for intramedullary pins--> explain Retrograde pinning versus Normograde pinning. Which bones do you use which technique in? (only these bones!)Retrograde pinning: from fracture site. Use in femur, humerus Normograde pinning: from bone end. Done in tibia, femur, humerus why is the tibia only for normograde??? because if do retrograde you will enter the articulation
retrograde vs normograde IM pin insertion--> which bone can you only do one of these on, and why? which bone can you NOT do ANY IM pin on?TIBIA ONLY NORMOGRADE bc if retrograde will hit articular surface. NEVER IN RADIUS bc there is no Apophysis (normal bony outgrowth that arises from separate ossification center and fuses with the bone in course of time.) so you can't go in from the side like in other bones
what should the length of the intramedullary pin be?All the bone length (from metaphysis to metaphysis) (if only in diaphysis, its kinda empty, so not a good anchor). Be careful not to get joints/nerves
how can you measure where your IM pin length is so you know you aren't too close or too far?have same sized pin on outside to see it
what is an Interlocking nail? When do you use it? Why?use in combo with a intramedullary pin. Can be screws or bolts working as the "nail". This is only used for straight bones (dogs don't have many of these tho). Good for neutralizing ALL forces. Minimally invasive- just fix pin with guide stab (do stab incision where you're gonna put it)
interlocking nail--> which is stronger, screw or bolt?bolts wider therefore stronger
how do you make sure the interlocking nail actually goes in the right place at the right angle?there is a guide, fix the nail to the guide
what are the three major uses for K-wires?(remember: K-wire is basically a small pin <2mm) (used to tx fractures in joints or close to joints) (1) Salter-Harris fractures (2) Small bone fragments (fast healing areas/stable fx) (3) Tension band (help to make tension band devices)
do you use K-wire in the diaphysis? (remember: K-wire is basically a small pin <2mm) no, small contact surface, might collapse (whereas a salter-harris has a large amount of contact once reduced so it works well)
how do you place the K-wire (arrangement)can do Crossed or Parallel, but you always need more than one pin in order to avoid rotational forces!!
what instruments do you need to place K-wires?Jacobs chuck or power drill, Cutting pliers, pliers
what type of "pins" are used for intramedullary pinning?Steinmann pins
in summary: what are steinmann pins used for and what are K-wires used for?(1) Steinmann pins: IM Pinning. (remember: Only bending forces will be addressed, need to address other forces with additional implants). K-wire: used for Growth plate fractures (or salter harris), can be applies parallel or crossed but need more than one to prevent rotation

Sx: Orthopedic wire

Question Answer
what are the three ways to use orthopedic wire to fix a fx?(1) Cerclage (around the bone to fix a fx) (2) Interfragmentary wires (mandibular fx) (3) Tension band device
explain Cerclage wire. what kinda wire do you use? What is the diameter? what instruments do you need to apply it?Use orthopedic wire (can bend and wont break), there are different diameter wires for diff jobs. You can use just pliers & cutting pliers (pic: pull AND twist at same time) , or you can use Special tension instruments
when can you use cerclage wires to fix fx? (which types of fx basically, generally)only for fixing SIMPLE FX where anatomical reduction is possible. Pic is barrel analogy: Need to be able to perfectly anatomically reduce or the tension of the wire wont help
how many cerclage wires should you use per fx? which (morphology wise) fx can you use cerclage wires on? Can cerclage be used stand-alone?Need two or MORE cerclage wires. You use for spiral or oblique fractures (but longer oblique fx, if small, not effective. Can't use on transverse, or complex/communited fx). Often you combine with other implants to inc stability (pic: also an IM wire)
what happens if you try to use cerclage wire in a comminuted or otherwise un-anatomically-reducible fracture?The wire will start moving and dec the blood supply to the periosteum (BAD...healing even LONGER)
why MUST cerclage wire be under tension?movement--> damage blood supply!
when are interfragmentary wires used? How do you do it?Mandible / maxilla fractures, Scapula / flat bones. Drill holes on either side of fx and put it around the fx
what is a Tension Band Device? What does it do? Used when?TBD is a combo of K-wire and cerclage wire, which turns Distraction forces into Compression forces! Avulsion fractures (apophyses), or Olecranon, Trochanter major, Tuberositas tibiae, Malleoli...)
Describe how a tension band device worksturns Distraction forces into Compression forces! Avulsions are caused by mm pulling on the bone, so you want compression. K wires should be as perpendicular as possible and then cerclage should be around pins and through a hole into the bone and then tightened. So then, when animal's mm contracts, the wire will contract, and create more compression