Intro to Ortho and Fracture Fixation Methods - Betance Flashcards
Definition of a Fracture
complete or incomplete break in the continuity of bone or cartilage
Goal of fracture repair
the early return of the patient to full funciton of the limb
How many methods of fracture classification are there?
six
Methods of Classification:
- direction of the fracture on the bone
- location of the fracture on the bone
- reducible or non-reducible
- displacement of fracture segments
- open or closed fracture
- specific types of factures
What is a comminuted fracture?
More than 2 pieces of bone
What is a long oblique fracture
if length of oblique fracture is >2x diameter of the bone
Who/where does Salter Harris fractures commonly occur?
Young animals at the growth plate
SH Type I
Straight Across
SH Type II
Above
SH Type III
Lower or beLow
SH Type IV
Two or Through
SH Type V
ERasure of growth plate or
Basic definition of Open fracture
at some point developed communication with external environment
Basic definition of Closed fracture
No communication with the external environment
Open Fracture Type I
- bone penetrating thru skin
- laceration < 1cm
- Clean
Open Fracture Type II
- External object penetrates soft tissue
- laceration > 1cm
- mild soft tissue trauma
Open Fracture Type IIIa
- vast soft tissue laceration
- soft tissue available for closure
Open Fracture Type IIIb
- extensive soft tissue injury and loss
- bone exposure and stripped periosteum
Open Fracture Type IIIc
- arterial supply damaged
- requires arterial repair for limb salvage
What is the number one cause of direct insult fractures
Over 75% are HBC
What is an indirect insult?
Force transmitted through bone to distant point (like the femoral neck, tibial tuberosity)
What does reduction mean?
reestablishing normal alignment of fracture fragments
Closed reduction:
reducing a fracture without surgically exposing the fractured bones
What does performing a closed reduction accomplish?
- preserves soft tissue and blood supply
- decreases risk of infection and OR time
What are some indications for performing a closed reduction?
- closed fracture below elbow or stifle
- bone will be stable after reduction
- quickly healing fracture
- small dogs/cats
- greenstick, intact periosteal sleeve, impaction fxs
What is an open reduction?
surgical approach to expose fracture in order to reconstruct and stabilize
What does an open reduction accomplish?
- direct visualization of fx to facilitate reconstruction
- allows direct placement of implant and load sharing
Indications for open reduction
- unstable and displaced fractures
- articular surfaces
- delayed healing
- bone grafts
What are the Rules for Open Reduction
- Halstead’s principles
- follow normal separations between muscles and fascial planes
- if muscles need to be severed, do it near origins or insertions
- preserve soft tissue and blood supply
Things about Transverse Fractures
- stable in compression
- unstable in bending
- unstable in rotation
- ideal for load sharing
Things about Oblique fractures
- unstable in compression
- less unstable in bending and rotation when compared to a transverse fracture
Things about Comminuted fractures
- unstable in compression
- unstable in bending
- unstable in torsion
- fracture will displace or collapse when forces are applied
- no load sharing
Fixator: Steinmann Pins aka IM pins resist what?
bending forces ONLY
Indication for IM pins
- fractures of the humerus, femur, tibia, ulna, metatarsal, and metacarpal
Contraindication for IM pins
radius fractures, most fractures in medial and large dogs
IM pinning RETROGRADE
pin is inserted at FRACTURE SITE
- humerus, femur
IM pinning NORMOGRADE
pin is inserted at MOST PROXIMAL AREA OF BONE
- humerus, femur, tibia
Where is the IM pin placed
medullary cavity of bone
Does an IM pin require any adjunct fixation
Almost ALWAYS!!!
- cerclage wire, ESF, plate
Is stack pinning common?
Nope, rarely used.
- 2+ pins to fill the medullary cavity
- higher incidence of pin migration
- difficult cutting multiple pins
When do you implement cross pinning?
with simple proximal/distal fractures
- physeal fractures
- smaller diameter smooth pins
What forces does cross pinning counteract
rotational and bending forces
What specific kind of fractures is cross pinning good for?
growth plate fractures, specifically Salter Harris II
What is rush pinning used for?
simple proximal and distal fractures
What kinds of forces does rush pinning resist?
bending and torsional forces
How many points of contact do rush pins have?
THREE!
- the pin is forced to bend to provide dynamic forces on the bone
What are diverging pins for?
stabilize Salter Harris I fractures of proximal humerus and femur
What don’t you do with diverging pinning?
penetrate the joint surface
What must you achieve with diverging pinning?
anatomical reduction!!!!
What is orthopedic wire used for?
used with IM pins, ESFs, and plates
Larger diameter of orthopedic wire means what in relation to strength?
Higher tensile strength
When would you use full cerclage wire?
with long oblique or spiral fractures in which the fracture line is at least 2x the diameter of the bone
- maximum of 3 fx segments
- fx must be anatomically reduced
- young/healthy patients combo w/ IM pin
When would you never use full cerclage wire?
a fully comminuted fracture
what would you use hemicerclage wire for?
short oblique diaphyseal fractures
What would you use skewer pins for?
short oblique fractures
What do skewer pins incorporate?
full cerclage wire and K-wire
Tension band wires are used for a lot of things. What are they?
- avulsion fractures or osteotomy of the greater trochanter
- avulsion fracture of tibial tuberosity
- fracture or osteotomy of the medial malleolus or olecranon
- fracture of tuber calcanei or acromial process of scapula
What’s the main theory behind tension band wires?
2 distractive forces become compressive forces
What are interfragmentary wires used for?
- simple fractures of flat, non-weight bearing bones that interdigitate well
- certain mandibular and maxillary fractures
- basically “suture” with wire
What are external skeletal fixators for?
- many open or closed fractures
- limb deformities
- when blood supply compromised
- need stabilization and wound access
- when bone purchase insufficient for plate
- arthrodesis
Are external skeletal fixators invasive or non invasive?
They offer less invasive fixation
Which is more stable, external skeletal fixators or plate fixators?
Plate fixation is more stable!!
which is more desirable, open or closed placement?
Closed!!! but only if fracture is reduced
What type of fixator is a unilateral-uniplanar?
Type Ia
What fractures is a unilateral-uniplanar fixator used on?
- radial fractures
- tibia-medial surface
- femur and humerus - lateral surface
- often used in combo with IM pin on femur and humerus
What type if fixator is a unilateral-biplanar?
Type Ib
What fractures is a unilateral-biplanar fixator used on?
- radius: craniomedial or craniolateral
- tibia: craniomedial
What kind of fixator is a bilateral-uniplanar?
Type II
What fractures is a bilateral-uniplanar fixator used on?
radius and tibia
- CANNOT USE ON THE FEMUR AND HUMERUS
What type of fixator is a bilateral-biplanar?
Type III
What fractures is a bilateral-biplanar used on?
ONLY the radius and tibia
What is the most common placement of a Type Ia fixator?
1 side of the bone in 1 plane
What is the most common placement of a Type Ib fixator?
1 side of the bone on 2 planes
What is the most common placement of a Type II fixator?
2 sides of the bone on 1 plane
What is the most common placement of a Type III fixator?
2 sides of the bone on 2 planes
Circular/Ring fixators are used when?
- complex fractures with no other alternatives
- limb shortening or lengthening procedures
- angular deformities
- transport of bone segements
How does the circular/ring fixator place tension?
by weight
