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108 Cards in this Set
- Front
- Back
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What are 75-85% of fractures caused by?
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motorized vehicle trauma
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What should you always do first with a fracture patient?
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a throrough physical exam to determine if there are any life threatening injuries
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What should you do to temporarily treat a fx while you are tending to the other life threatening injuries?
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Wound treatment with lavage, culture, sterile lube, wound dressing
Short term stabilization - robert jones bandage, splint, sling or muzzle |
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Once your patient is stabilized what will you do?
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full ortho and neuro exam
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What are 6 clinical signs of a fracture?
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pain/local tenderness
deformity abnormal mobility local swelling loss of fxn crepitus |
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T/F to take rads of suspected fx's you should sedate or administer GA and take 1 view
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False - sedation and GA and 2 orthogonal views
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What are the possible tx plans for fxs?
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conservative - rest, external coaptation
Surgical reduction and stabilization referral for sx repair elsewhere |
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What are the 4 causal factors of fx's?
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Direct violence - HBC
Indirect violence - force transmitted through bone or muscle (avulsion fx) Diseased bone - neoplasia or nutritional Repeated stress - greyhounds |
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What are the 6 types of forces that create fx's?
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compression
bending torsion tension repetitive loading high velocity (more soft tissue damage) vs. low velocity |
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Describe a compression fx
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force applied axially to the long bones or vertebra - causes oblique fx's
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Describe a bending fx
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tensile forces on either side of the bone and compressive forces on the opposite side - causes transverse or transverse with small butterfly fx's
ex: little dog jumps out of owners arms |
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What type of fracture does torsion cause?
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spiral fx
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T/F Tension usually causes transverse fx's
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true - ex: avulsion fx where the bone is attached to stron ligament or tendon
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What does repetitive loading cause? What breed is most commonly affected? Which bones?
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Repetitive loading causes stress fractures
Greyhounds are most common metatarsals |
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Describe low velocity fractures
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usually a single fracture with minimal ST injury ex: falling off the couch
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Describe a high velocity fx
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usually comminuted fx's with significant soft tissue injury - multiple limbs may be involved
ex: HBC |
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T/F When describing a fx you describe the position of the proximal fragment relative to the distal fragment
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False - describe the distal fragment relative to the proximal
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How do you describe the location of a fracture (what should you include)
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bone affected
side of the animal it's on if it is a paired bone where within the bone is the fx - epi/meta/diaphysis and if it's artiicular or not |
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When are fractures considered an emergency? (needing repair within 24 hours)
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any time the articular surface is involved
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What are the components of fracture description (7)
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complete vx incomplete
avulsion fissure short vs long oblique spiral transvers comminuted (minimal = 3pcs vs highly comminute = 20 pcs |
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What determines if a fracture is reducible or non-reducible?
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directly related to the energy that caused the trauma
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what does reduction mean
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replacing the fracture fragments in their anatomical positions
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what does alignment mean?
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longitucinal position of the proximal and distal fragments relative to each other
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What is apposition?
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the amount of contact of the fracture fragments with each other (50% apposition, 75%, etc)
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How do you prevent fragment motion during healing?
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fixation - immobilization - stabilization
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T/F It is more common to have open wounds where there is less soft tissue
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True - metacarpals/tarsals
radius/ulna tibia/fibula |
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t/f the more soft tissue damage there is the slower bone healing will be
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True due to decreased blood suppply
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What types of fx stabilization are available? (7)
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plates and screws
interlocking nails external skeletal fixators IM pins and cerclage wire Screws tension band external coaptation |
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When are plates and screws ideal for fx repair?
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long bone fx
multiple/complex fx fx in large breed dog |
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What are the pros of plates and screws
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restores rigid stability to reconstructed fx
ideal for early return to fxn of the injured limb minimal care from the owners perspective |
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What are the cons of plates/screws?
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Not good for open fx due to infection/contamination
placement of the plate req's extensive ST disruption |
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What is the fxn of plate screws?
Positional screws? Lag screws? screws in general |
plate screws - hold the bone plate in position
positional screws - interfragmentary lag screws - produce compression between two fragments general - screws can be used as anchors for synthetic ligaments or tendon repairs |
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What are external skeletal fixators?
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a percutaneous fixation with wires inserted into bone - pins are connected by one or more connecting bars or columns
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When is the use of an ESF indicated? (6)
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comminuted fx
open/infected fx non-unions/delayed unions correctin of growth deformity transarticular stabilization adjunct to other internal fixation |
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What are the advantages of ESF?
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applied with closed or minimall open technique
no foreign material at the fx site access to wound management apparatus can be altered to decrease stability as the fx heals |
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What are interlocking nails?
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large intramedullary pins that are secured to the cortices by interlocking screws proximal and distal to the fx - provide rotational stability
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In what 3 bones can an interlockin nail be used?
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tibia, humerus, and femur
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how do intramedullary pins work?
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they provide 3 point fixation
angular stability is controled by seating the pin in the bone at either end and impingment on the inner cortex. |
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How much of the medullary cavity should be occupied by an IM pin?
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70% of the cavity at the narrowest point
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T/F it is ok to use IM pins alone
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FALSE - use with cerclage wires
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What is cerclage wire and when is its use indicated?
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orthopedic wire that can be looped around the entire circumference of a bone
Indications: neutralization of forces in long oblique fx stabilize fissures compress long oblique butterfly fragments |
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When is tension band wiring used?
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1 - to repair avulsion fx of the apophyses (olceranon, tibial tuberosity, greater trochanter of the femur where muscle attachment is strong)
2- repair osteotomies Most stable when the animal is bearing weight |
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When is external coaptation use appropriate?
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young patients
incomplete fx distal limbs |
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What is required of the fx site in order for external coaptation to be used?
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adequate fxnal alignment
apposition of at least 50% the cast must extend above the joint proximal to the fx and below the jt distal to the fx\ |
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What type of fx is external coaptation used most for?
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transverse fx - or for extra stability with internal fixation
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t/f external coaptation can be used for comminuted fx
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false
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What are the 4 forces acting on a fx?
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1- distraction or tension
2- compression or shearing 3 - rotation or torsion 4- angular/bending |
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What do you use for fx repair to minimize distraction and/or tension forces?
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tension band wiring
lag screw fixation plate and screw fixation |
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What do you use for fx repair to minimize rotation or tension force?
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External Skeletal fixation
plate and screw interlocking nail cerclage wire and bone screws can be used in conjunction with these |
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how do you minimze shearing/compression forces on your fx repair? (what type of fixation?
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external skeletal fixation
plate and screw fixation interlocking nail (cerclage wire and lag screws) |
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What type of fx repair would you use to minimize angular and bending forces on the fx
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external skeletal fixation
plate fixation interlocking nail (IM pins, or external coaptation can als be used) |
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T/F Ideally the implant and the bone should share the load equally?
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True
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t/f fx fixation should maintain axial alignment and bone length as well as providing rotational stability
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true
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What determines the type of bone healing (primary vx secondary)
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the degree of stability
more rigid fixation - primary bone healing less rigid fixation - secondary bone healing |
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t/f absolute stability means faster and better healing
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false - not necessarily
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what is primary bone healing
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bone is the first and only type of connective tissue to form between fragments 0 it is no faster and not necessarily bettter than secondary bone healing
get primary healing with a bone plate |
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t/f fractures with secondary healing (callus formation) are biomechanically weaker than primary bone healing fxs at any given point
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FALSE!!!
primary fx healing is weaker than secondary bone healing at any given point |
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What is secondary bone healing
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intermediate external supportive cartilage forms - occurs when the repair doesn't provide adequate reduction or immobilization of fragments - healing occurs with a radiographically visible periosteal callus - occurs with external coaptation
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what is one fundamental objective of treating fxs?
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maintain/preserve blood supply!!!
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What are the 5 sources of blood for bone?
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nutrient artery
medullary artery metaphyseal arteries epiphyseal arteries surrounding soft tisse (especially early on in the repair) |
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T/F Extraosseous blood supply arises from the soft tissue
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true - supplies blood for early periosteal callus
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What are the objectives in fx treatment?
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early active pain free mobilization of muscles and joints with return to normal fxn
prevent fx dz |
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What 3 factors affect bone healing?
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Mechanical factors
Biologic factors clinical factors |
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What are the mechanical factors of bone healing?
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Number of limbs affected
patient size/activity ability to achieve load-sharing fixation between bony column and implant reducibility of the fx |
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What do the biology factors indicate?
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how fast callus will be formed and therefore how long the implates/coaptation will be needed to support the bone
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list some biologic factors that affect fx healing
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age
general health open vs closed fx low energy vs high energy (soft tissue dmg) which bone is injured and the location of the injury |
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t/f there is increased time to heal fx of the distal limb
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true - dicreased soft tissue / blood supply surrounding it
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Which type of bone heals faster? Cancellous or cortical?
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cancellous bone heals faster
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what are the clinical factors affeecting fracture repair
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Patient and client factors - willingness/ability of client to attend to post-ops needs
patient cooperation post op post op limb fxn |
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What type of clients should you avoid external coaptation or ESF? patients?
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unwilling clinets
uncontrollable or agressive patients - avoid ESFs |
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What are skeletal/striated muscle fibers made up of?
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long cylindrical fibers (myofibers) formed into bundles (fasciculi)
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t/f myofibrils lie within sacrolemmal sheath
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true
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What two types of striated fibers are nearly all skeletal muscles composed of ?
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type 1 fibers- small diameter with abundance of myoglobin and cabable of prolonged sustained activity
Type 2 fibers- white fibers - large diameter, low concentration of myglobin capable of short bursts of rapid activity |
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t/f the more fibers a muscle has the stronger it is
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true
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Each muscle fiber is surrounded by an interconnecting connective tissue fill in the following blanks
_____________supports each individual fiber _____________supporst each fiber bundle _____________suuprts the entire muscle and delineates one muscle from another |
endomysium supports each ind fiber
perimysium supports each fiber bundle epimysium supposrt entire muscle and delineates one muscle from another |
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T/f Fibrous connective tissue septa contain blood vessels and nerves, bind and integrate the action of the individual fibers and allow freedom of movement b/w individual muscle components and muscles
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True
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What are the 3 types of connection of skeletal muscle to bone or cartilage
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cordlike tendon
flat aponeurosis directly to the periosteum by fleshy attachment |
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What are the 4 main types of muscle injury
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contusion
strains laceration rupture |
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What is a muscle contusion?
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bruising or hematoma formation within a muscle that causes separation of the muscle fibers - contusions result from traumatic injuries and often accompany fxs
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how do you treat acute muscle contusions?
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ICE - immobilization, cold and elevation
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How do you treat chronic muscle contusions?
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immobilization, HEAT, compressive wraps or protective bandages (keep dog from licking). Rest and NSAIDS (meloxicam and rimadyl) because contusions cause an increase in WBC's = inflamm
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What are muscle strains?
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injury to the muscle - tendon unit where the tendon and muslce come together from oversretching or overuse of the muscles - can be acute (single/sudden 1st 2nd or 3rd degree)
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how do you treat muscle strain/
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immobilization and exercise restriction
NSAID (meloxicam/rimadyl?) +/- hydrotherapy |
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What causes muscle lacerations?
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penetration and/or tearing of the muscle by sharp objects such as teeth glass tin cans, nails. The patient usually has an open wound and non-weight bearing lameness
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how do you treat muscle lacerations
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initially with open wound management, irrigation, explore to determine extent, carefully debride, and place appositonal sutures in the outer muscle sheath for the full circumference of the muscles. appositional sutures are supported with tension/stent sutures
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Describe muscle ruptures
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muscle ruptures can be partial or complete and result from powerful, active contraction of a flexor motor unit a the same time as forced passive extension (flexors and extensors are working at the same time)
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t/f tendons are more resistant to trauma than muscle
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FALSE - muscles are more resistant to trauma than tendons therefore ruptures at the musculo-tendon jxn rupture more commonly than rupture of the muscle belly
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Muscle rupture is more common in ___________ (young/old) dogs and tendon rupture is more common in _______(young/old) dogs.
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muscle - young because tendons are still relatively pliable (also avulsions are more common in young dogs than muscle rupture)
tendons - old dogs |
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what kinds of dogs are more prone to muscle rupture
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sporting dogs and performance athletes (racing greyhounds)
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how do you treat incomplete muscle ruptures?
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tx acutely with ICE (immobilization, cold packs and elevation)
The immobilization prevents further separation of the torn muscle, allows optimal myofiber regeneration and minimizes scar formation |
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how do you treat complete muscle ruptures?
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repaired by anatomical alignment of muscle ends by end-to-end anastomosis
-gentle tissue handling -end approximation with lg horzontal mattress suture (non-reactive non-absorbable), using stents or buttons to tie the suture to disperse the pressure over a larger area and decresase suture pulling through tissue -once edges are apposed suture the muscle sheath -immobilize for 2-3 wks then slowly return to activity after 4-6 weeks |
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how do you immobilize the limb for complete muscle rupture repair
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the leg should be supported in a manner that they can't ben d the leg so use a splint, or heavy robert jones bandage...as they are improving move to a padded bandage and begin to increase activity
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What are the clinical signs of incomplete muscle disruption?
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lcoal sweelling/tenderness
ecchymotic hemorrhages - brusiing and lameness - wtbearing, transient (<24 hrs), and more evident at faster gaits |
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What are the clinical signs of complete muscle rupture
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acute onset lameness/altered gait +/- wtbearing
swelling palpable discontinuity in the muscle itself |
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t/f muscle cells (myofibrils) can regenerate?
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true
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What is req'd for msucle cells to regenerate/
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sarcolemmal nucleus for regeneration
an intact endomysial tube is requ'd to reconstruc muscle |
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What are the 2 types of muscle atrophy?
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disuse - mild/mod atrophy that takes a while to develop
denervation - more severe alteration in shape and more rapid due to injury of spinal cord or peripheral nerve |
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what are the 3 specific muscle injuries that you would commonly see?
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1- rupture of the serratus ventralis muscle (that holds the scapula down) causing dorsal scapular displacement - more common in cats due to jumping
2- rupture of the gracilis muscle and the long head of the triceps brachii muscle (racing greyhounds) 3- muscular or musculotendinous rupture of the achilles mechanism |
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What is mucscle contracture/fibrosis caused by?
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fibrous connective tissue repleacement of muscle generally affecting the infraspinatus, gracilis and quad muscles
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What are the 3 etiolgies of muscle contracture/fibrosis
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trauma to muscle fibers, nerves, or blood vessels producing degenerative changes within the muscle
congenital sequel to infectious or autoimmune dz |
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What are the 3 causes of quadriceps muscle contracture/fibrosis? which is most common?
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Trauma - most common
2ndary to parasitic infecion - neospora canis congenital predisposition |
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What happens with quadriceps fibrosis/contracture
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fibrous adhesions develo b/w the quads mechanism and the femur (femoral callus)
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When does quad fibrosis/contracture occur?
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most often in immature dogs with distal femoral fx (salter haris 1 or 2 fx of the distal growth plates of the femur). Associated with prolonged immobilization and or inadequate fixation
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What occurs as a result of quadriceps fibrosis? (2ndary)
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results in secondary disuse osteoporosis muscle atropphy, and degenerative and fibrotic intraarticular and periarticular changes
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A dog comes to you with its hind limb in hyperextension. On PE neither the stifle nor the hock can be flexed and the patella is drawn proximally in the trochlear groove. The muscles are atrophied and fibrotic. What is your diagnosis
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Quadriceps fibrosis or contracture
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What 4 factors contribute to the development of quadriceps contracture?
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1-periosteal stripping during injury repair
2-exuberant callus from inadequate fx repair (young dogs with very active periosteum) 3-traumatized muscle -from the originating injury or 2nd to sx 4-limb disuse |
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What are the 3 treatment methods for quadriceps contracture?
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sx - release adhesions b/w quads and femur and myoplasty to lengthen restrictive quad muscles
aggresive physio immediately - sedate the day after sx and start physio- fibrous scar in muscle can elongate w/ intensive physio but always have loss of power (never more than 50% of normal strength) Salvage procedure - arthrodesis or amputation (more common) |
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What is the prognosis for Quad fibrosis/contracutre?
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guarded to poor - adhesions tend to reform post op
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