Long Bone Fractures 1

Question 1

85% of long bone fractures in young racehorses are….

Answer 1

lateral condylar fractures

Question 2

In a thoroughbred horse, which is a more common fracture location, MCIII or MTIII?

What about in a standardbred?

Answer 2

in TB, its 2x more likely to be MCIII

in SB, they are about equal

Question 3

T/F: Long bone fracture etiology is usually NOT due to a single event injury

Answer 3

T

Question 4

What is the most common etiologic pathway for a long bone fracture in equine?

2. leads to ______
3. causes ____/____
4. end result is ___ fracture

Answer 4

1. High compressive load
2. Leads to osseus adaption/sclerosis
3. microtrauma/microfracture
4. condylar fracture

Question 5

What is the most common clinical presentation for a non-displaced incomplete fracture in equine?

Answer 5

history of lameness with acute exacerbation

Question 6

What are the three signs of the clinical presentation that would suggest an acute displaced fracture in an equine?

Answer 6

1. acute onset of severe lameness after intense exercise
2. effusion of MCP/MTP joint
3. Pain on palpation

Question 7

Condylar fracture treatment:

Answer 7

Internal fixation with transcortical screws in lag fashion

Question 8

First aid components for a lateral condylar fracture include:

1.
2.
3.

Answer 8

1. Compression bandage
2. NSAIDs
3. ABSOLUTE stall rest until definitive tx is undertaken

Question 9

During the articular alignment stage during the treatment of a lateral condylar fracture, it is very important that there is no…..

Answer 9

cartilage gap

Question 10

In a lateral condylar fracture repair, the first screw is placed (close to / far from) the joint?

Ideal location?

Answer 10

1. close to

2. Epicondylar fossa

Question 11

Lag screw repair of condylar fracture:

1. Screw size?
2. Place screws how far apart?
3. Most require how many screws?

Answer 11

1. 4.5 mm or 5.5 mm cortical bone screws
2. 20 mm
3. only 2

Question 12

Prognosis for RTR for condylar fracture if:

1. non-displaced or incomplete?
2. displaced?
3. worst prognosis if ____

Answer 12

1. 70-80%
2. 50%
3. joint comminution exists

Question 13

Most common long bone fracture in horses?

Answer 13

Diaphyseal fractures of the cannon bone (MCIII and MTIII)

Question 14

Prognosis for diaphyseal fractures of MCIII and MTIII are dependent on _______.

Best treatment method?

Answer 14

immediate 1st aid.

External coaptation via Double Plate Fixation.

Question 15

Cannon Bone Fracture Repair:

Plates are placed on the (tension/non-tension) side of the bone.

_____ compression is EXTREMELY IMPORTANT

Answer 15

tension.

Inter-fragmentary

Question 16

Fracture compression during treatment of Cannon Bone fractures:

1. ______ is used to compress a fracture with a plate.
2. Max __mm compression using plate holes.

Answer 16

1. load drill guide.

2. 4 mm

Question 17

Types of plates used for repair of cannon bone fractures?

1.

2.

3.

4.

Answer 17

1. Dynamic Compression (DCP)
2. Limited Contact - Dynamic Compression (LC-DCP)
3. Locking Compression (LCP)
4. Anatomic / Specialty

Question 18

Plates for Cannon Bone Fracture Repair:

Which one is preferred? Why?

Answer 18

LCP - it’s specifically designed for equine fracture repair.

Question 19

What are the two benefits of a LC-DCP?

Answer 19

1. Continuity of bending stiffness

2. Improved blood supply under plate

Question 20

4 main functions of plates during cannon bone fracture repair

1.
2.
3.
4.

Answer 20

1. Compression
2. Neutralization - placed after anatomic reconstruction so the screws are inserted in a neutral position
3. Tension band - transforms tensile forces into compressive forces
4. Buttressing - placed to bridge the area of bone defect

Question 21

Cannon bone fracture repair:

Maximum # of screws placed on either side or fracture?

Placed when fracture (is/is not) under load?

Answer 21

1. 2

2. when it is under load

Question 22

Name the type of Plate:

It’s self-compressing, the screws can be angled in many direction, it can be adapted to different internal fixation needs, and the screws can be placed orthogonally or up to a 25 degree angle.

Answer 22

DCP

Question 23

Name the type of plate:

It has a limited contact with a grooved undersurface, it has a uniform stiffness, and it has a DCU hole that allows screws to be placed at a 40 degree angle.

Answer 23

LC-DCP

Question 24

T/F: LC-DCP plates are adaptable for different internal fixation needs?

Answer 24

T

Question 25

Name the type of plate: It can undergo dynamic compression, it has limited contact and a grooved undersurface, It has combi-holes that permit the combination of conventional or locking screw, and it can be applied with minimal invasiveness.

Answer 25

5.5mm LCP

Question 26

Screws used with LCP plates: What are the two kinds? What size are they in mm? What are their functions?

Answer 26

Locking and Cortex Locking is 4.0/5.0 mm Cortex is 4.5/5.5 mm Locking screw provides angular stability, cortex screw provides compression/neutralization

Question 27

LCP can be placed using ____ screws or _____ screws.

Answer 27

standard screws or locking screws

Question 28

What are the two main benefits of using locking screws to place an LCP?

Answer 28

1. increased stability | 2. increased fixation strength

Question 29

Horses must be _____ and ______ in the IMMEDIATE post-op period after plating

Answer 29

ambulatory and fully weight-bearing

Question 30

Challenges for large animal fracture fixation: 1. 2. 3. 4.

Answer 30

1. large plates occupy space making skin closure difficult 2. Implant failure 3. Post-op lameness (contralateral limb lamenesses) 4. Large animal specific orthopedic implants would facilitate equine fracture repair

Question 31

Ulnar Fracture etiology: | 1.

Answer 31

1. Direct trauma via external trauma ie injury during halter training

Question 32

Most common presentation of ulnar fracture?

Answer 32

Dropped elbow with carpus in flexion

Question 33

DDx for Ulnar Fracture: 1. 2. 3. 4.

Answer 33

1. Humeral fracture 2. Radial nerve paralysis 3. Olecranon fracture 4. Neuro dx (rare)

Question 34

Ulnar Fracture: Results in disruption to the ______

Answer 34

Stay aparratus

Question 35

Do/do not use a splint for an ulnar fracture?

Answer 35

Do

Question 36

Why splint an ulnar fracture?

Answer 36

to fix the carpus in extension

Question 37

Splints for ulnar fractures should be applied to the (dorsal/palmar) side, extending from the ____ to the _____

Answer 37

palmar, fetlock to the level of the elbow

Question 38

If an ulnar fracture is in an animal less than 250 kg, you can repair it via..... if larger?

Answer 38

tension band technique (screws and wires) you must apply a plate

Question 39

Olecranon fracture repair: Treatment of choice?

Answer 39

ORIF

Question 40

Olecranon fracture repair: Use _____ principle

Answer 40

Olecranon fracture repair: tension-band

Question 41

Olecranon fracture repair: Plate applied to (caudal/cranial) ulna? What plates can you use?

Answer 41

caudal ulna Narrow DCP, LC-DCP, LCP

Question 42

Describe how you'd apply a bone plate for an olecranon fracture repair?

Answer 42

contour the plate to fit over the top of the olecranon tuberosity

Question 43

Olecranon fracture repair: In an adult horse, distal screws can be inserted in the _______. Why do this?

Answer 43

caudal cortex of the radius ensure a rigid fixation

Question 44

Olecranon fracture repair: Why would you not insert distal screws into the radius in a young horse?

Answer 44

it may lead to subluxation of the elbow

Question 45

Olecranon fracture repair: Prognosis?

Answer 45

Good with ORIF - 68-87%