Long Bone Fractures 1

Question 1

When must horses be ambulatory and fully weight-bearing post-internal plating of a bone fracture for a more favorable prognosis?

Answer 1

Immediately

Question 2

How is prognosis affected by articular involvement?

Answer 2

Decreases

Question 3

Where does a lateral condylar fracture of MC3 usually originate and which direction does it propagate?

Answer 3

Distal end, propagates abaxially up the bone

Question 4

What radiographic view is required to evaluate joint involvement of a lateral condylar MC3 fractures

Answer 4

Tangential view

Question 5

Which aspect of the bone does a tangential view highlight and what can it show you?

Answer 5

Palmar aspect highlights comminution at joint surface

Question 6

What % of condylar fractures in young racehorses are lateral?

Answer 6

85%

Question 7

Is MC3 or MT3 more commonly fractured in thoroughbreds?

Answer 7

MC3 2x more common than MT3

Question 8

Is MC3 or MT3 more commonly fractured in standardbreds?

Answer 8

They’re about equal

Question 9

What contributes to a cannon bone condylar fracture?

Answer 9

High compressive load = osseous sclerosis

Microtrauma = microfracture

Question 10

History of lameness w/acute exacerbation

Answer 10

Non-displaced incomplete fracture

Question 11

Acute onset of severe lameness after intense exercise, effusion, pain of fetlock

Answer 11

Acute displaced fracture

Question 12

What first aid measurements can you do for a cannon bone condylar fracture?

Answer 12

Compression bandage, NSAIDs, absolute stall rest til sx

Question 13

How big are the lag screws used to stabilize a cannon bone condylar fracture, how many are used, and how far apart are they placed?

Answer 13

Two 4.5mm/5.5mm screws placed 20mm apart

Question 14

Why is the first screw placed close to the joint?

Answer 14

Align joint surface first

Question 15

What is the px for repair of a non-displaced/incomplete cannon bone condylar fracture?

Answer 15

Favorable (70-80%)

Question 16

What is the px for repair of a displaced cannon bone condylar fracture?

Answer 16

50%

Question 17

What is the most common long bone fracture in horses?

Answer 17

Cannon bone diaphyseal fracture

Question 18

What does the px of a diaphyseal cannon bone fracture depend on?

Answer 18

First aid

Question 19

How do you surgically repair a diaphyseal cannon bone fracture?

Answer 19

Double plate fixation on tension side of bone

Question 20

How do you repair a comminuted diaphyseal cannon bone fracture?

Answer 20

Transform the fracture into 2 segments

Question 21

What is the max amount of fracture compression you can do for a comminuted diaphyseal cannon bone fracture?

Answer 21

4mm (2mm on either side of fracture)

Question 22

Continuity of bending stiffness and improved blood supply under this plate

Answer 22

Limited contact - dynamic compression plate (LC-DCP)

Question 23

A 5.5mm one of this kind of plate has been specifically designed for equine fracture repair

Answer 23

Locking compression plate (LCP)

Question 24

What are functions of a plate?

Answer 24

Compression, neutralization

Question 25

What plate technique is used to bridge area of bone defect, but unlikely to work if used in horses?

Answer 25

Buttressing

Question 26

Transforms tensile forces into compressive forces

Answer 26

Tension band

Question 27

Adaptable plate for different fixation needs, grooved undersurface, uniform stiffness

Answer 27

LC-DCP

Question 28

How do locking screws have to be placed to work correctly?

Answer 28

Orthogonally

Question 29

What plate has combi-holes to permit conventional or locking screw placement?

Answer 29

LCP

Question 30

Which screws increase stability and the fixation strength of the plate screw construct?

Answer 30

Locking screws

Question 31

Where do the triceps muscles insert?

Answer 31

Olecranon

Question 32

What is the most common cause of ulnar fractures?

Answer 32

Direct trauma

Question 33

How will a fractured ulna present?

Answer 33

Dropped elbow w/carpus flexion

Question 34

How do you splint an ulnar fracture and why?

Answer 34

Fix carpus in extension to maintain stay apparatus

Question 35

Which side of the limb do you place a splint on for an ulnar fracture?

Answer 35

Palmar

Question 36

What is the treatment of choice for an olecranon fracture?

Answer 36

ORIF

Question 37

Bone plate contoured to fit over the top of the oleranon tuberosity

Answer 37

ORIF

Question 38

Why should your ORIF repair not engage the radius in young animals?

Answer 38

Could risk damage and subluxation of elbow

Question 39

How can you repair a SH type 1 fracture of the olectranon in a <250kg patient? >250kg?

Answer 39

``` <250kg = tension band (screws and wires) >250kg = must apply plate ```

Question 40

What is the px for an ulnar fracture repaired with ORIF?

Answer 40

Good (68-87%)