Small Ani. Sx- Orthopedics- Fracture Tx- Treatment planning + Complications

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

intro + mechanical assessment + bio assessment + clinical assessment (Fracture Patient Assessment Score” (FPAS) )

Question Answer
The Fracture Patient Assessment Score” (FPAS) assesses what three things?Need to assess them and create a score. look at: (1) Mechanical assessment (2) Biological assessment (what bio factors will assess healing?) (3) Clinical assessment (is the animal crazy or calm?)
what are the three Mechanical factors you need to consider with your mechanical assessment?(1) Comminuted / reducible (2) Load sharing (do the implants need to take the load?) (3) Multiple legs injured (if more than one leg broken, need a really strong fixation)
mechanical assessment--> when accounting for the Stability of the fracture, you should consider a few things, like...Forces to be neutralized, Support of bone fragments, Estimated time of healing, Open/close, Age, Localization, Soft tissue injuries
mechanical assessment--> what is the relationship between fracture stability and implant stability?the more stable the fracture, the less stability of the implant needed. The more unstable the facture, more stable implant is needed.
mechanical assessment--> Mechanical fracture assessment scale (pic)
Biological assessment--> what are some factors you need to consider about the patient?Young / old, Soft tissue trauma, Open/close fracture, Location, Surgical approach
Biological assessment--> biological fracture assessment scale (pic)
Biological assessment--> young animal heal faster or slower?faster
Biological assessment--> which Surgical approach causes slower healing?if open bone for reduction--> kill blood supply--> heals slower
Biological assessment--> open or closed heal slower?open is slower healing
Biological assessment--> you must consider trauma to blood supply caused both by initial injury and by surgical trauma. You must also consider the age of the animal. How does age play into blood supply?When they are young, the periosteum is major supply, in older, endosteal supply
Reduced blood supply--> more reduction in simple or comminuted fx?more reduction in comminuted
Reduced blood supply--> more reduction in open or closed?open is more reduction
Reduced blood supply--> which type of trauma causes a reduced blood supply?gun shot (bc they break everything)
Reduced blood supply--> which bones tend to have dec blood supply and why?bones with Less soft tissue coverage (tibia, distal radius) tend to have less blood supply
surgical trauma which is faster to heal versus slowerSLOWER: Large approach, Anatomical reconstruction (if you gotta retract mm to visualize area etc), Fixation stable. (4-6wk for callus) FASTER: Mini/ no approach, Alignment, Fixation more elastic
Clinical assessment--> clinical fracture assessment scale (pic)
In summary, Mechanical assessment looks at what? Biological assessment looks at what? clinical assessment looks at what?mechanical: strength of fixation. Bio: time to healing. Clinical: is the animal or owner a jackass

Choice of treatment (he has a lot of examples in this section, i only put a few but sometimes they build on themselves so just look over them)

Question Answer
4yo DSH cat HBC. What treatment choice do you think?It is a comminuted fx of the tibia's diaphysis which cannot be reduced. Hence, you cannot use cerclage wire or tension band device. CAN use an external fixator or a bridging plate. You will need a STRONG implant bc bones wont be able to share load with implant.
is this compression, neutralization, or bridging?Bridging (not neut bc no other implants, not compression bc holes arent oval)
Why did this bend? how could you have prevented this?plate bent bc not strong enough to support entire weight of animal (no sharing of force bc comminuted tibia fx). Should have done LOAD SHARING (such as put an external fixator or a intramedullary pin in as well) (....or used a bigger and stronger plate)
<img src=""height="200"> what do you think you should do about this?femur diaphysis 3(?) fragments pelvis has 2 fractures joint is involved= need anatomical reduction and compression femur needs length and alignment not anatomical reduciton
you take a radiograph half way though treatment-- what can you look at to see if there is good blood supply to the area?If fragments have become rounded= good blood supply. If still sharp, no blood supply, high risk of sequestration

Complications: Healing-related complications + Implant failures + Osteomyelitis

Question Answer
4 major types of complications are...(1) Healing-related complications (2) Implant failures (3) Osteomyelitis (4) Growth deformities
what are the 3 kinds of Healing-related complications?Delayed union, Nonunion, malunion
what is Delayed union?Longer time to heal than anticipated
4 reasons there might be delayed union?Insufficient stability (too much movement--> bigger callus. Need to provide stability BEFORE it mineralizes), Reduced blood supply(can damage this with your sx approach), Large bone defect (will need to bridge), Status of patient (sick animal will take a long time)
3 treatments for a delayed union are...Time, Keep fracture stable, bone graft
what is Nonunion?Fracture that has failed to heal [non-unions must be sx treated]
what are the two types of non-unions?(1) Viable (hypertrophic)- Callus formation, but not bridging the gap. (2) Non viable- No callus formation
what is the cause of Viable nonunion􀀁 (Hypertrophic)? What prob does this non-union result in?Caused by instability of fx. This can lead to pseudoarthrosis which is basically a "fake joint" in the broken bone
what is the cause of a Nonviable nonunion?poor blood supply! (ex: only one cerclage wire, it was damaged, etc)
how do you treat a non-union?Always surgical!!! want to Increase stability if there is movement, open the medullary cavity (prox or distally, to facilitate blood supply to the bone), possibly do a bone graft
what are two types of bone grafts you might be able to use to try to tx a non-union? (downsides of each?)(1) Autogenous- take it from themselves at same time of repair, very painful (2) Allogenic (banks)- bank grafts can't do osteogenesis bc they are not alive
4 harvesting sites for an autogenous bone graft?Proximal Humerus, Ilium, Distal Femur, Proximal Tibia.... **NEEDS TO BE CANCELLOUS BONE! If you take it from the diaphysis there will only be fat not marrow and shit
********3 main Functions of bone graft?(1) Osteogenesis (make new bone) (2) Osteoinduction (chemical mediators to conduct bones to differentiate into bone producing cells) (3) osteoconduction (osteoblasts and fibroblasts can come from blood supply--> fill a gap in the bone so the cells can jump in to where they need to be)
when is it contraindicated to use a bone graft?Never contraindicated to use bone graft!!!!!! (worst that happens is that it gets resorbed)
what is malunion?Healed fractures bad alignment
malunion can be a malalignment-- what is going on in a malalignment?basically causing a valgus or varus
how do you tx a malunion?Corrective osteotomies
Implant failure--> examples of technical errors which can cause implant failure?Small implants, Short plates, Wrong positioning of plate, Heat necrosis, Secondary to delayed healing, Not enough screws (3 or more per fragment), Plates too short (always bridge all the length of bone), Plate too weak/small, bad screw hole, Incorrect positioning of plate, Infections, Blood supply damage
not enough screws can cause implant failure--> how many screws per fragment?3
plates being too short can cause implant failure-- how long SHOULD they be?always bridge all the length of bone
why can short plates lead to implant failure?too much loaded and they get loose
Wrong positioning of plate can lead to implant failure-- WHERE should the plate be? (tension or compression side?)TENSION SIDE
how might implant failure be Secondary to delayed healing?implants don't last forever- might need to change the plate (ex pins get loose, need to replace them)
what is Osteomyelitis? how do they get this?Inflammatory condition of the bone (Infection). Can be hematogenous or post-traumatic
what are the main agents responsible for osteomyelitis? (3)Staphylococcus sp, E. Coli, Pseudomonas (typically found on the skin of the dog, always use gloves when dealing with open fx)
what are examples of ways that agents responsible for osteomyelitis are able to get to the bone?(Staphylococcus sp, E. Coli, Pseudomona) Local ischemia, Trauma, sx, Bone necrosis and sequestration, Fracture instability (movement allows bact to get in), Biofilm (glycocalyx) (this makes it impossible for abx to reach the area), foreign material
how can you dx osteomyelitis? (general, acute, and chronic?) what kind of complication can Pain upon palpation. ACUTE cases you will also see swelling and a fever. With CHRONIC you will see draining tracts. Can also be maybe predicted with Healing-related complications (like implants getting loose)
what does osteomyelitis look like on radiographs?Periosteal proliferation, Sclerosis, Loose implants, Broken implants, Sequestrum (need to remove to let bone heal)
how do you treat osteomyelitis?****Surgical debridement (need to open it up!! abx will not reach the area otherwise! THEN CULTURE THAT SHIT), abx, drainage, local lavage, bone graft, Stabilize the fracture, External fixator
so you're trying to fix this osteomyelitis, and you open it up and you flush it out and you take out the crappy bone plate and sequestrum....then what?place an external fixator, leave that shit open yo, treat the bone like an open wound. Wet to dry bandages are your friends.
Osteomyelitis--> So then you left the bone open like an open wound and wet to dry bandaged it....uh, well you can't do that for forever, now what?wait till there is nice granulation tissue, lavage and debride again in you need, stick some bone graft in there, then you can close it up
In summary: Healing related complications is concerned with what 2 things?blood supply and stability.
In summary: Implant failure is usually due to...technical errors
In summary: if you want to fix osteomyelitis, you MUSTDO SX TX
a possible complication is growth deformities, will learn this in salter harris lectureoh yay