Small Ani. Sx- Orthopedics- Salter Harris fractures

wilsbach's version from 2015-11-25 17:05

intro and general

Question Answer
Uh, so about that refresher on endochondral ossification.... (pic)
what occurs at the physis?Longitudinal bone growth, Endochondral ossification
bone grows by what two processes? what dietary problem messes this up?bones grow by simultaneous deposition and reabsorption. So if there is too much Ca in the diet, wont be reabsorbed--> dysplasia
how common is a growth plate fracture? how strong is a growth plate compared to other bone stuff?30% of fractures in young animals are at the physis...probably due in part to the fact the Growth plate 2-5 times weaker than ligaments/bone
what are the types of salter harris fractures?His diagram: some other helpful diagram:
what is Type 1 salter harris?through the growth plate
what is Type 2 salter harris?through growth plate and then into metaphysis (typical of distal femur)
what is Type 3 salter harris?through physis and then into epiphysis
what is Type 4 salter harris?through metaphysis, physis, AND epiphysis (typical of distal humerus)
what is Type 5 salter harris?centrally crushed growth plate, completely crushed growth plate (usually distal ulna)
what is Type 6 salter harris?growth plate crushed on one side (fibrous tissue will bridge the crushed growth plate and cause asymmetric closure)
Prognosis can depend on many things, but three things in particular are...younger patient? larger breed? localization? (such as distal ulna) [pretty sure he means these are bad things]
Principles of treatment of S-H fx (read over)ALWAYS SURGICAL!!!, Rigid fixation, Early reduction, Small implants (K-wires), Avoid blocking growth plate (no screws/ plates), Protect blood supply, Implant removal 2-4 weeks, Early physiotherapy
can you medically manage SH fx?NO, ALWAYS SX!
do you want flexible or rigid fixation for SH fx?RIGID
do you want to wait to reduce, or reduce early?EARLY reduction
what kinda implants do you wanna use to fix a SH fx? what DONT you want?SMALL implants (like K-wires!!), but no screws or plates bc you want to avoid blocking the growth plate
about how long till you remove implant in SH fx?2-4wk

Specific areas

Question Answer
7 most common areas for a SH fx?BOTHS: Distal AND prox femur, Distal AND proximal tibia. DISTALS: Distal humerus, Distal ulna, Distal radius (listed most to least common is--- Distal femur, Distal humerus, Proximal femur, Distal ulna, Distal radius, Proximal & distal tibia)
*Distal femur gets what kinda SH fx?Type II (through growth plate and up into metaphysis)
goals of fixing SH fx?Anatomical reduction, Stable fixation, Full mobility
(mentioned in class) what is a nasty secondary problem to fx of femur?quadriceps contracture is 2ry to femoral fx in young dogs. Prognosis is very very bad. Flex stifle and tarsus when bandaging to help avoid, dont extend the leg completely
what sx do you do to fix a SH Type 2 fx of the distal femur?Lateral arthrotomy
how do you reduce a type 2 SH fx of the distal femur?push the tibia to reduce
which implants used in what way do you do for a SH Type 2 fx of the distal femur?Do Cross pinning with small K wires (cats 1.0mm!) (BEND the pins and then cut them to desired length- if dont bend might damage femoro-patellar joint)
*Proximal femur gets what kinda SH fx?Type 1 (right through the growth plate) (can be trauma or idiopathic)
what is Feline physeal dysplasia syndrome? where and what kinda SH fx does this happen with? what KIND of cats are more prone?proximal femur SH type 1 fx... castrated and obese more prone
castrated and obese animals are more prone to what kinda SH fx and why?Type 1-- bc if you neuter an animal growth plates take longer to close, and extra weight is more force on them
Canine epiphysiolisis usually occurs where with which type of SH fx?proximal femur, SH type 1
what must you keep in mind about blood supply and SH fxs?First no blood supply from metaphyseal side bc cant go through the cart of the growth plate. THEN, the epiphysis is really small so not much blood supply also. So necrosis, like of the proximal femur, is a nasty problem
proximal femur SH type 1 fx-- what are your 3sx treatment options?(1) K- wires (2) FHO: femoral head ostectomy (3) Total Hip Replacement
proximal femur SH type 1 fx-- how would you place the K-wires?
proximal femur SH type 1 fx- better or worse prog if younger?younger is WORSE (prolly bc less blood supply and prolly uneven growing?)
Does a dog or cat have a better prognosis for a proximal femur SH Type I fx?cat bc they have a better blood supply to there
what is a phenomena which gives a poor prognosis when trying to repair a proximal femur SH Type I fx?"apple core" phenomena (femoral neck narrow bc too much resorption)
*the distal humerus tends to get which type of SH fx? Through which condyle?Type 4 (through epiphysis, physis, and metaphysis) thus it is INTRAARTICUALR, and is through the lateral condyle (lateral more load bearing bc articulates with the radius)
how do you repair a distal humerus type 4 SH fx?(lateral condyle usually) Since it is INTRAARTICULAR you will need Anatomical reduction! Thus, Lag screws
*What is the most common SH fx for the distal ulna?S-H 5 (compression)
where does most of the ulna's length grow from?distal physis-- so of course this is the one that breaks (type 5)
why is SH fx of the distal ulna difficult to dx, and what can you do to help dx it?bc it's a type 5 so its compression, so harder to see. try to dx by Repeat radiographs at 2 weeks, and Compare with other side
(only said in class) tx for SH type 5fx of distal ulna?do ulna ostectomy to allow radius to grow in proper direction

Growth deformities

Question Answer
3 growth deformities which can result from SH fx?(1) Premature closure of growing plates(Salter Harris fractures) (2) Malalignment (3) Short bones
what is Radius curvus?distal ulna tends to get type 5 compression fx--> early growth plate closure. So then it stays short and RADIUS KEEPS GROWING LONGER-- starts to bend (curve) and cause deformity.
how do you treat Radius curvus?Corrective osteotomy
what is Distraction osteogenesis, what do you do, what does it help correct? What is the LIMIT of this sx?correct length (if its too short) by pulling bones apart and letting bone fill in between them to make them longer. pull apart, place external fixator, let bone grow and heal, remove external fixator. The bone can grow to whatever length you want, HOWEVER you are limited by how long the flexor tendons will go- they are not very flexible.
what two steps can you take to help prevent radius curvus from occuring when there is a SH type 5fx of the distal ulna?(1) In doubt: periodical radiographic controls (2) Ulna ostectomy (remove piece of the bone) so ulna isnt causing tension on the radius
*distal radius tends to get which SH fx?S-H type 1 (straight through the physis) (also type 6 can happen)
SH type I fx of distal radius-- how do you tx?cross pins
If there is a S-H 6 fx of the distal radius, how can you help tx this?take saw and remove fibrotic tissue bridging the physis
what is this tx? what is it used for? tension band device, apophyseal fx
Apophyseal fractures usually happen because...Growth plates under tension from tendons and ligaments
3 most common places for avulsion fractures?Tub. tibial, Trocanter mayor, Tub. supragenoideo
tx apophyseal fx with...?tension band device (said in class: leave pins but remove tension band after like 1 wk or the bone will become deformed bc tuberosity will stop growing but rest of bone keeps going, boney mess)
Summary: do SH fx usually need small implants or large implants?small, bc joint takes all the bending forces
summary: prognosis depends on location and age of trauma... which age is a worse prog and why?younger is worse prognosis, bc more potential of growing= bad