Surgery Lecture Intro To Fracture Principles

Front 1

What are the 5 forces acting on a fracture?

Back 1

1) Bending
2) Axial compression
3) Tension
4) Shear
5) Rotation

Front 2

What are the 5 components of fracture classification?

Back 2

1) Which bone
2) Location on the bone
3) Fracture type
4) Fracture displacement
5) Open or closed

Front 3

What are 5 different locations on a bone?

Back 3

1) Epiphysis
2) Physis
3) Metapysis
4) Diaphysis
5) Articular

Front 4

What is a type I salter harris fracture?

Back 4

Just through the growth plate (physis)

Front 5

What is a type II salter harris fracture?

Back 5

Through physis and metaphysis

Front 6

What is a type III salter harris fracture?

Back 6

Through physis and epiphysis
-no potential for arthritis and angular limb deformity

Front 7

What is a type IV salter harris fracture?

Back 7

Through physis, metaphysis and epiphysis

Front 8

What is a type V salter harris fracture?

Back 8

Crushing injury
-often happens silently like falling off couch then becomes lame and 3 mo later leg is bending

Front 9

How does the score of a salter harris fracture reflect the prognosis?

Back 9

Higher the score worse the prognosis
-partial physeal fractures can lead to angular limb deformity

Front 10

Fractures in the joint cause ____.

Back 10

arthritis

Front 11

Are physeal fractures an emergency?

Back 11

Yes

Front 12

What are 6 fracture types?

Back 12

1) Transverse
2) Short oblique
3) Long oblique
4) Spiral
5) Comminuted
6) Avulsions

Front 13

Why is classifying the fracture type so important?

Back 13

Determines the forces that need to be counteracted in order to stabilize the fracture and how much the bone is damaged
-controls what fixation methods are used!

Front 14

What is a greenstick fracture?

Back 14

When one cortex is intact and one is broken

Front 15

Describe the load sharing of transverse fractures.

Back 15

Intrinsic stability in compressive loading

Front 16

What characterizes a long oblique fracture?

Back 16

Fracture is at least 2x longer than diaphysis width

Front 17

Describe the load sharing of a long oblique fracture.

Back 17

Some intrinsic stability in lateral bending
-when apply compressive weight bearing force there's no intrinsic stability

Front 18

Describe the load sharing of a spiral oblique fracture.

Back 18

Some intrinsic stability in lateral bending

Front 19

Describe the load sharing of a comminuted fracture.

Back 19

No load sharing
-need very sturdy implants

Front 20

What views are required to determine fracture displacement?

Back 20

Orthogonal views

Front 21

How do you describe fracture displacement?

Back 21

Describe the position of the distal segment

Front 22

How can you identify an open fracture via radiographs?

Back 22

Gas may be present

Front 23

Are open fractures an emergency?

Back 23

yes, requires IV antibiotics, emergency lavage/ debridement & fixation

Front 24

Why do open fractures take longer to heal?

Back 24

Damaged blood supply and bacteria

Front 25

What is a grade 1 open fracture?

Back 25

Cause of the communication is bone penetrating the skin
-very minimal soft tissue and vascular damage

Front 26

What is the prognosis of a grade 1 open fracture?

Back 26

Usually good

Front 27

What is a grade 2 open fracture?

Back 27

Communication is caused by external trauma
-moderate soft tissue & vascular damage
-no lost of soft tissue or bone

Front 28

What is a grade 3 & 4 open fracture?

Back 28

Communication is caused by severe external trauma (high energy)
-extensive soft tissue, vascular, and/or bone damage & loss

Front 29

What are the 3 ways to describe the guarded prognosis of grade 3 & 4 open fractures?

Back 29

1) 3a: does not require reconstructive surgery
2) 3b: requires reconstructive soft tissue surgery
3) 3c: major arterial injury requiring repair

Front 30

How is a type IV open fracture different from type III?

Back 30

Type IV is near amputation/ needs amputation

Front 31

How long should antibiotics be administered to an animal with an open fracture?

Back 31

Infected bone must be treated 2 months and assume an open fracture means infected bone!

Front 32

What are 4 antibiotics that have pretty good bone penetration?

Back 32

1) Clavamox
2) Enrofloxacin
3) Clindamycin
-but are bacteriostatic
4) Chloramphenicol
-can cause aplastic anemia

Front 33

Why must the implants be removed from an open fracture?

Back 33

Because of the bacterial biofilms that form

Front 34

What are the 4 AO principles of fracture repair?

Back 34

1) Anatomic reduction of fracture fragments
2) Stable fixation
3) Preservation of blood supply and soft tissues
4) Early, active, pain free mobilization of muscles and joints adjacent to the fracture to prevent fracture disease

Front 35

True or false. Orthopedic surgery is the LOWEST priority when dealing with a hit by car.

Back 35

True, stabilize the patient first!!!
Has thoracic, abdominal and neurologic injury been ruled out or addressed?

Front 36

What are the 4 A's of fracture repair?

Back 36

1) Alignment
2) Apposition
3) Apparatus
4) Activity

Front 37

What does alignment refer to regarding fracture repair?

Back 37

Orientation of the joints
-are the joints back in a normal, anatomic position?

Front 38

What does apposition refer to regarding fracture repair?

Back 38

Fracture reduction; contact of the fracture ends

Front 39

How much of the bone segments must be touching for healing to occur?

Back 39

At least 50% of the bone segments need to be touching

Front 40

What does apparatus refer to regarding fracture repair?

Back 40

The fixation method
-did you follow implant or casting rules?

Front 41

What does activity refer to regarding fracture repair?

Back 41

Bone healing activity
-is the bone healing at a normal rate

Front 42

How long does it take bone to heal in an animal < 3 mo of age?

Back 42

2-4 weeks
-why we don't keep splints on longer than 2 weeks in puppies because joint contracture

Front 43

How long does it take bone to heal in an animal 3-6 months of age?

Back 43

4-12 weeks

Front 44

How long does it take bone to heal in a dog 6-12 months old?

Back 44

5-16 weeks

Front 45

How long does it take bone to heal in an animal 1 year or more?

Back 45

7-30 weeks

Front 46

What is the "fracture healing race"?

Back 46

A race b/w time it takes for the bone to heal and failure of the implants or implant/ bone interface

Front 47

What are the 4 choices for fracture fixatoin?

Back 47

1) Do nothing- usually not a good idea
-results in fracture disease, permanent disability & pain, sometimes death
2) Splint
-usually not stable enough
3) Cast
-only very specific cases will benefit
4) Surgery

Front 48

What are the 3 types of surgery that can be performed for fracture repair?

Back 48

*1) Open reduction w/ internal fixation
*2) Closed reduction w/ external fixation
-don't open bone & try to align w/o opening the leg & put fixation on outside of limb
3) Minimally invasive surgery (specific cases)

Front 49

What are 2 advantages of open reduction/ internal fixation?

Back 49

1) Allows bone grafting
2) Allows anatomic reconstruction of fracture pieces
-if possible load sharping b/w pieces

Front 50

When is open reduction imperative for fracture repair?

Back 50

Articular and physeal fractures

Front 51

What are 2 disadvantages to open reduction/ internal fixation?

Back 51

1) Prolongs surgery
2) Damages blood supply and disrupts fracture blood clot mileau

Front 52

What are 5 types of apparatuses used for internal stabilization?

Back 52

1) Plates
2) Interlocking nails
3) Intramedullary pins & cerclage wire
4) Kirschner wires/ steinman pins
5) Pin & tension bands

Front 53

What type of force do plates resist?

Back 53

Resist forces in all directions
-bending, axial compression, tension, torsion

Front 54

How are plates placed during fracture repair?

Back 54

Placed eccentrically to long axis of bone, thus susceptible to repeat bending stresses

Front 55

How can you increase the strength of a plate?

Back 55

Addition of an IM pin 30-40% of medullary canal diameter increases strength immensely

Front 56

What type of forces are resisted by interlocking nails?

Back 56

-Nail portion has excellent resistance to bending
-Locking screws or bolts provide resistance to rotation & compression forces

Front 57

What fractures do we like to use IM pins and cerclage wire for?

Back 57

Long oblique/ spiral fissure

Front 58

What types of forces are pins resistant to?

Back 58

Bending in any direction
-poor resistance to axial compression, rotation and have minimal bone interlock

Front 59

How big should an IM pin be?

Back 59

Pin diameter must be 70% of the medullary canal width

Front 60

What type of force is cerclage wire resistant to?

Back 60

Can resist axial compression and some rotation
-poor resistance to bending

Front 61

True or false. IM pins can provide adequate support alone.

Back 61

False, Never use IM pins OR cerclage wire alone

Front 62

What do you want to use to repair physeal fractures?

Back 62

Kirschner wires/ steinman pins
-ONLY use these on physeal fractures

Front 63

Why are Kirschner wires/ steinman pins used for physeal fractures?

Back 63

Smooth pins allow continued physeal growth
-always place more than 1!!!!

Front 64

How are Steinman pins placed?

Back 64

In parallel or crossed
-Avoid the joint!!!!!!!!

Front 65

How do pins and tension bands deal with forces applied on the bone?

Back 65

Converts tensile forces into compressive forces

Front 66

When do we use pins and tension bands for fracture repair?

Back 66

Use on avulsion fractures where muscles insert

Front 67

What are 6 locations where you would want to use a pin and tension band to repair avulsion fractures?

Back 67

1) Olecranon
2) Greater tubercle
3) Greater trochanter
4) Tibial tuberosity
5) Maleoli
6) Styloid process

Front 68

What is closed reduction/ external fixation?

Back 68

Fracture reduction and limb alignment without surgically exposing bone fragments

Front 69

What are 3 advantages of closed reduction?

Back 69

1) Preserves soft tissue blood supply
2) Very helpful in highly comminuted, non anatomically reconstructible fractures
3) Decreases risk of iatrogenic contamination/ infection

Front 70

What is a disadvantage of closed reduction?

Back 70

Cortical apposition and limb alignment are harder to achieve

Front 71

What are 2 apparatuses used for external fixation?

Back 71

External fixation
Hybrid fixation

Front 72

What is required in order to apply an external fixator?

Back 72

Requires SAFE soft tissue "corridors"
-hitting nerves, muscle bellies, vessels or body wall is not allowed
-pretty much anywhere can feel bone directly under skin

Front 73

What is a type 1A external fixator?

Back 73

Uniplanar external fixator

Front 74

What is a type 1B external fixator?

Back 74

Biplanar external fixator

Front 75

What is a type II external fixator?

Back 75

Uniplanar external fixator
-but have one placed on each side

Front 76

What is a type III external fixator?

Back 76

Combination of type 1a and type II so very strong

Front 77

What are 7 types of external fixators?

Back 77

1) Type Ia
2) type IB
3) Type II
4) Type III
5) Ring or illizarov fixator
6) IM pin "tie-in"
7) Free-formpolymethylmethacrylate with half pins

Front 78

What are minimally invasive techniques?

Back 78

Closed approach, requires a C-arm fluoroscope

Front 79

What is the advantage of minimally invasive techniques?

Back 79

Avoids soft tissue damage

Front 80

What are 4 apparatuses used with minimally invasive techniques?

Back 80

1) Interlocking nails
2) Locking plates
3) External fixators
4) Cross pins/ screws

Front 81

**What are 3 things you need to consider when trying to figure out which fixation technique to use?

Back 81

1) Biologic: healing potential
-blood supply, age, overall health
2) Mechanical
-fracture configuration, number of dysfunctional limbs
3) Client compliance
-activity restriction, meds, follow up

Front 82

**What type of stabilization do yo u want to use for the 3 categories of fracture assessment?

Back 82

1) buttress (worse)
-multiple limb injury
-giant breed
2) Contact
-preexisting clinical disease
-large dog
3) Compression
-Single limb
-smaller dog

Front 83

When considering the biologic fracture assessment what are 6 cautions?

Back 83

1) Old patient
2) Poor health
3) Poor soft tissue envelope
4) Cortical bone
5) High velocity injury
6) Extensive approach
-have to filet everything open

Front 84

What is a mini approach?

Back 84

Less soft tissue injury than extensive approach
-much lower on the biological fracture assessment scale

Front 85

When considering the biologic fracture assessment what are 6 factors that prove little risk?

Back 85

1) Juvenile
2) Excellent health
3) Good soft tissue envelope
4) Cancellous bone
5) Low velocity injury
6) Closed

Front 86

When performing clinical fracture assessment what are 4 factors that imply caution?

Back 86

1) Poor client compliance
2) Poor patient compliance
3) Wimp
4) High comfort level required

Front 87

When performing clinical fracture assessment what are 4 factors that indicate little risk?

Back 87

1) Good client compliance
2) Good patient compliance
3) Stoic
4) Comfort level not a consideration

Front 88

***Describe the fractures that get low scores (0-3) on fracture assessment. What type of apparatus should be used for repair?

Back 88

Non reducible fractures in older animals with extensive soft tissue surgery
-Use plates, interlocking nails, plate-rods, type III or ring fixators
*strongest fixation possible

Front 89

Describe a fracture that gets a moderate score (4-7) on fracture assessment. What type of apparatus do we want to use?

Back 89

More stable fracture, older dog OR
Less stable fracture type, younger dog
-Use type 1-B or II fixator, plates, interlocking fix

Front 90

What fractures get a high score (8-10) on fracture assessment? What type of apparatus should be used for fixation?

Back 90

Good load sharing, young dog
-type I external fixator, IM pin + cerclage, cast