Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
69 Cards in this Set
- Front
- Back
|
What is required for a bone plate to be an effective therapeutic strategy?
|
Good bone above and below the fracture
|
|
|
What are 4 ways to avoid the avoidable when performing fracture repair?
|
1) Anticipate the forces placed on a fracture
2) Anticipate the patient’s ability to heal 3) Anticipate complications 4) Anticipate client compliance with activity restriction orders *THEN choose the fracture fixation method |
|
|
What is the worse type of break (scores the lowest on the mechanical fracture assessment)?
|
Buttress (lots of pieces)
|
|
|
Where does a break with one large chunk broken but still in contact with the other two pieces place on the fracture assessment score?
|
About a 5 (middle)
|
|
|
Where does a compression (transverse) break place on the fracture assessment score?
|
High- little risk because low shearing so these implants not as much of a mechanical risk
|
|
|
where does a fracture in the cortical bone place on the fracture assessment score?
|
Caution!! low- high risk
|
|
|
Where does a fracture of cancellous bone place on the fracture assessment score?
|
High- low risk
|
|
|
Where do high velocity injuries place on the fracture assessment score?
|
Low= high risk!!!
|
|
|
Where does a stoic dog place on the fracture assessment score?
|
High= low risk
-wimp= low, caution! |
|
|
Where does that require high comfort level place on the fracture assessment score?
|
Low= caution
|
|
|
Looking at the big picture, what fractures place really low (0-3) on the fracture assessment score?
|
Non reducible fractures in older animals w/ extensive tissue injury
|
|
|
**What do you want to use to repair fractures that place low on the fracture assessment score?
|
Plates, interlocking nails, plate-rods, type III or ring fixators
|
|
|
Looking at the big picture, what fractures get a moderate score (4-7) on the fracture assessment score?
|
Older dog, more stable fracture
Less stable fracture type, younger dog |
|
|
**What do you want to use to repair fractures that score a 4-7?
|
Type 1-B or II fixator, plates, interlocking nails, IM + external-fixator
|
|
|
What's an example of a high score fracture?
|
Good load sharing, young dog
|
|
|
*What do you want to use to repair a fracture with a high score (8-10)?
|
Type I external fixator, IM pin + cerclage, cast
|
|
|
What are the 4 A's of fracture repair?
|
Alignment, apposition, apparatus, activity
|
|
|
what does alignment apply to when analyzing fracture repair?
|
Orientation of the ***joints
-Are the joints back in a normal, anatomical position? |
|
|
What does apposition refer to when analyzing fracture repair?
|
Fracture reduction; contact of fracture ends
-Are at least 50% of the bone segments touching? |
|
|
What does the apparatus refer to when repairing a fracture?
|
The fixation method
-Did you follow implant or casting rules? |
|
|
Will a single IM pin work to repair a transverse fracture?
|
No!!! need at least cerclage wire or an external fixator
|
|
|
What does activity refer to when analyzing fracture repair?
|
Bone healing activity
-is the bone healing at a normal rate? |
|
|
How long should it take a bone to heal in an animal that/s <3 mo old? 3-6 mo old? 6-12 mo old? 1 year or more?
|
<3 mo: 2-4 weeks
3-6 months: 4-12 weeks 6-12 mo: 5-16 weks 1 yr or more: 7-30 weeks -more comminuted and older the animal the longer it will take to heal |
|
|
What happens when you ignore the 4 As of fracture repair?
|
Can cause malunion, delayed union or nonunion fractures
|
|
|
*What is the definition of malunion?
|
A fracture or osteomy (cut by surgeon) that HEALED in a non anatomic position
|
|
|
What are 5 causes of malunion?
|
1) Inadequate or failed stabilization
2) Inadequate reduction 3) Impaired blood supply 4) Infection 5) Bone loss |
|
|
What is the consequences of malunion?
|
Angular limb deformities:
-joint incongruity -osteoarthritis in adjacent joints -contracted soft tissues -shortened bone -mechanical pain or pain induced lameness |
|
|
What are 4 biological consequences of an ingrown pelvis (malunion)?
|
1) Obstipation
2) nerve damage 3) Urethral entrapment 4) Lameness |
|
|
What are the consequences of intra-articular and growth plate malunions?
|
angulated limb
ARTHRITIS -pain, disability, increased weight bearing on other limbs |
|
|
What are 2 ways to "treat" malunion?
|
1) Prevent- learn your orthopedics
-use early & appropriate fracture fixation -appropriate post-op care (activity restriction) -Recheck films to follow healing 2) Corrective osteotomies |
|
|
What is delayed union?
|
A fracture that is healing, but is taking longer than expected
-diagnosis is very subjective and requires SERIAl film to document rate of bone healing |
|
|
What are 2 clinical signs of delayed union?
|
1) Persistent lameness
2) Pain on palpation of the fracture |
|
|
What are 2 radiographic signs of delayed union?
|
1) Fracture line is still visible on films but may be fuzzy or wooly appearing
2) Callus is visible but may not be bridging fracture |
|
|
What are 6 causes of delayed union?
|
1) Inadequate stabilization
2) Inadequate reduction -need 50% of bone apposition 3) Large fracture gaps 4) Poor bone blood supply -traumatic, mini/toy breed dogs distal extremities 5) Infection -will heal if rigidly stabilized but will take longer 6) Systemic factors -age, malnutrition, corticosteroids, uncontrolled neuropathies |
|
|
What are 4 ways to treat delayed union in a fracture that is stable?
|
1) Continue rigid stabilization
2) Treat infection 3) Owner compliance -activity restriction, sling walking 4) Follow up PE & films |
|
|
What are the 3 components of treating delayed union in a fracture that is unstable?
|
1) Re-do fracture reduction and alignment if unsatisfactory
2) Original fixation is too weak: augment it! -add external fixator, change to plate 3) Bone graft |
|
|
What are the 3 types of bone grafts?
|
1) Osteoinduction
2) Osteoconduction 3) Osteogenesis |
|
|
What is osteoinduction?
|
mesenchymal progenitor cells differentiate into osteoblasts after contacting matrix and growth factors from the graft
|
|
|
What is osteoconduction?
|
Graft provides 3-D scaffold for bone ingrowth
|
|
|
What is osteogenesis?
|
formation of new bone
|
|
|
What can you use to get mesenchymal progenitor cells?
|
Autogenous cancellous bone - get from femur etc. can differentiate into osteoblasts if put in right environment
|
|
|
What is the definition of nonunion?
|
All evidence of bone healing at the fracture has ceased
-ununited fracture +/- pseudoarthrosis ***Will not heal without surgery |
|
|
What are the causes of nonunion fractures?
|
Same as malunion
-inadequate stabilization -inadequate reduction -large fracture gaps -poor bone blood supply -infection -systemic factors |
|
|
How common are nonunion fractures?
|
Rare- 4% of fractures
-does happen in mini-breeds bc have a terrible blood supply |
|
|
What are 5 clinical signs of nonunion?
|
1) Lameness (non weight bearing)
2) Muscle atrophy 3) Palpable instability 4) Angular limb deformity 5) Pseudoarthroses may not be painful |
|
|
What are 6 radiographic signs of nonunion?
|
1) Radiolucent fracture site
2) Sclerosis at fracture sites 3) Callus does not bridge fracture -or absent callus 4) Medullary cavity sealed off 5) Bony resorbtion 6) Osteoporosis |
|
|
What are the 3 types of viable nonunions?
|
1) Hypertrophic viable nonunions
2) Moderately hypertrophic viable nonunion 3) Oligotrophic viable nonunion |
|
|
What is a viable nonunion?
|
-Still has blood supply
-some biological bone healing activity -cartilage and fibrous tissue in fracture gap -still has potential for healing |
|
|
What is the prognosis of viable nonunions?
|
Fair to good w/ surgery
|
|
|
What is hypertrophic viable nonunion?
|
"elephant's foot" shaped bony callus
-nonossified bridging callus -bony proliferation at fragment ends |
|
|
What usually causes the abundant callus caused by hypertrophic viable nonunion?
|
Too much fracture motion
|
|
|
What is a moderately hypertrophic viable nonunion?
|
"horse's hoof" shaped bony callus
-less callus than hypertrophic nonunion |
|
|
What is oligotrophic viable nonunion?
|
Very little callus
-fibrous tissue only in gap |
|
|
How do you distinguish oligotrophic viable nonunion from nonviable nonunions?
|
By hazy, fuzzy appearance
|
|
|
What are 7 components of treating viable nonunions?
|
1) approach: preserve blood supply
2) Remove loose implants 3) Correct joint alignment if necessary 4) May need to open medullary canal 5) Culture & sensitivity 6) Autogenous cancellous graft 7) PROVIDE RIGID FRACTURE FIXATION |
|
|
What are the 4 types of nonviable nonunions?
|
1) Dystrophic nonviable nonunions
2) Necrotic nonviable nonunions 3) defect nonviable nonunions 4) atrophic nonviable nonunion |
|
|
What are the characteristics nonviable nonunions?
|
-little to no vascular supply
-little to no biological bone healing activity -least common -grave prognosis |
|
|
What is dystrophic nonviable nonunion?
|
One or both sides poorly vascularized
|
|
|
How does dystrophic nonviable nonunion appear on films?
|
Fracture gap is rounded, distinct, with non viable sclerotic ends
|
|
|
What are the most common circumstances surrounding dystrophic nonviable nonunion?
|
Commonly seen in distal radius/ ulna fractures of toy breeds
|
|
|
What is necrotic nonviable nonunion?
|
Unicorporated fracture fragments that become sequestra (Dead bone)
|
|
|
How does necrotic nonviable nonunion appear on films?
|
-fracture gap is rounded, distinct, with sclerotic ends
-fragments are sclerotic with sharp, distinct edges |
|
|
What is defect nonviable nonunion?
|
Fracture results in severe bone loss
-gap 1.5x bone diameter too large to allow bridging -fracture gap is too large to allow proper bridging |
|
|
How does defect nonviable nonunion appear on films?
|
Fracture gap is rounded, distinct, with sclerotic ends
|
|
|
Where are defect nonviable nonunions common?
|
In areas w/ limited soft tissue e.g. distal tibia
|
|
|
What is atrophic nonviable nonunion?
|
End-stage pseudoarthrosis
-NO osteogenic activity at all -Medullary cavities sealed w/ bone |
|
|
How does atrophic nonviable nonunion appear on films?
|
Rounding, sclerosis, and resorption of fracture ends, osteopenia
-bone has given up |
|
|
What is the treatment of nonviable nonunion? (5)
|
1) Remove fibrous tissues
2) Open medullary canal 3) Culture and sensitivity 4) cancellous bone graft 5) DURABLE RIGID INTERNAL FIXATION -healing may take 4-6 hours -multiple surgeries may be required |
|
|
What are 4 nonstandard methods of treating nonunion and delayed union fractures?
|
1) Growth factors
-BMP, insulin-like growth factor, fibroblast growth factor, transforming growth factor -beta 2) Pulsed electromagnetic fields 3) Low intensity pulsed ultrasound 4) Extracorporeal shock wave therapy |
