Long Bone Fractures 1 Flashcards
85% of long bone fractures in young racehorses are….
lateral condylar fractures
In a thoroughbred horse, which is a more common fracture location, MCIII or MTIII?
What about in a standardbred?
in TB, its 2x more likely to be MCIII
in SB, they are about equal
T/F: Long bone fracture etiology is usually NOT due to a single event injury
T
What is the most common etiologic pathway for a long bone fracture in equine?
- leads to ______
- causes ____/____
- end result is ___ fracture
- High compressive load
- Leads to osseus adaption/sclerosis
- microtrauma/microfracture
- condylar fracture
What is the most common clinical presentation for a non-displaced incomplete fracture in equine?
history of lameness with acute exacerbation
What are the three signs of the clinical presentation that would suggest an acute displaced fracture in an equine?
- acute onset of severe lameness after intense exercise
- effusion of MCP/MTP joint
- Pain on palpation
Condylar fracture treatment:
Internal fixation with transcortical screws in lag fashion
First aid components for a lateral condylar fracture include:
1.
2.
3.
- Compression bandage
- NSAIDs
- ABSOLUTE stall rest until definitive tx is undertaken
During the articular alignment stage during the treatment of a lateral condylar fracture, it is very important that there is no…..
cartilage gap
In a lateral condylar fracture repair, the first screw is placed (close to / far from) the joint?
Ideal location?
- close to
2. Epicondylar fossa
Lag screw repair of condylar fracture:
- Screw size?
- Place screws how far apart?
- Most require how many screws?
- 4.5 mm or 5.5 mm cortical bone screws
- 20 mm
- only 2
Prognosis for RTR for condylar fracture if:
- non-displaced or incomplete?
- displaced?
- worst prognosis if ____
- 70-80%
- 50%
- joint comminution exists
Most common long bone fracture in horses?
Diaphyseal fractures of the cannon bone (MCIII and MTIII)
Prognosis for diaphyseal fractures of MCIII and MTIII are dependent on _______.
Best treatment method?
immediate 1st aid.
External coaptation via Double Plate Fixation.
Cannon Bone Fracture Repair:
Plates are placed on the (tension/non-tension) side of the bone.
_____ compression is EXTREMELY IMPORTANT
tension.
Inter-fragmentary
Fracture compression during treatment of Cannon Bone fractures:
- ______ is used to compress a fracture with a plate.
- Max __mm compression using plate holes.
- load drill guide.
2. 4 mm
Types of plates used for repair of cannon bone fractures?
1.
2.
3.
4.
- Dynamic Compression (DCP)
- Limited Contact - Dynamic Compression (LC-DCP)
- Locking Compression (LCP)
- Anatomic / Specialty
Plates for Cannon Bone Fracture Repair:
Which one is preferred? Why?
LCP - it’s specifically designed for equine fracture repair.
What are the two benefits of a LC-DCP?
- Continuity of bending stiffness
2. Improved blood supply under plate
4 main functions of plates during cannon bone fracture repair
1.
2.
3.
4.
- Compression
- Neutralization - placed after anatomic reconstruction so the screws are inserted in a neutral position
- Tension band - transforms tensile forces into compressive forces
- Buttressing - placed to bridge the area of bone defect
Cannon bone fracture repair:
Maximum # of screws placed on either side or fracture?
Placed when fracture (is/is not) under load?
- 2
2. when it is under load
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.
DCP
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.
LC-DCP
T/F: LC-DCP plates are adaptable for different internal fixation needs?
T
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.
5.5mm LCP
Screws used with LCP plates:
What are the two kinds? What size are they in mm? What are their functions?
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
LCP can be placed using ____ screws or _____ screws.
standard screws or locking screws
What are the two main benefits of using locking screws to place an LCP?
- increased stability
2. increased fixation strength
Horses must be _____ and ______ in the IMMEDIATE post-op period after plating
ambulatory and fully weight-bearing
Challenges for large animal fracture fixation:
1.
2.
3.
4.
- large plates occupy space making skin closure difficult
- Implant failure
- Post-op lameness (contralateral limb lamenesses)
- Large animal specific orthopedic implants would facilitate equine fracture repair
Ulnar Fracture etiology:
1.
- Direct trauma via external trauma ie injury during halter training
Most common presentation of ulnar fracture?
Dropped elbow with carpus in flexion
DDx for Ulnar Fracture:
1.
2.
3.
4.
- Humeral fracture
- Radial nerve paralysis
- Olecranon fracture
- Neuro dx (rare)
Ulnar Fracture:
Results in disruption to the ______
Stay aparratus
Do/do not use a splint for an ulnar fracture?
Do
Why splint an ulnar fracture?
to fix the carpus in extension
Splints for ulnar fractures should be applied to the (dorsal/palmar) side, extending from the ____ to the _____
palmar,
fetlock to the level of the elbow
If an ulnar fracture is in an animal less than 250 kg, you can repair it via…..
if larger?
tension band technique (screws and wires)
you must apply a plate
Olecranon fracture repair: Treatment of choice?
ORIF
Olecranon fracture repair:
Use _____ principle
Olecranon fracture repair:
tension-band
Olecranon fracture repair:
Plate applied to (caudal/cranial) ulna?
What plates can you use?
caudal ulna
Narrow DCP, LC-DCP, LCP
Describe how you’d apply a bone plate for an olecranon fracture repair?
contour the plate to fit over the top of the olecranon tuberosity
Olecranon fracture repair:
In an adult horse, distal screws can be inserted in the _______. Why do this?
caudal cortex of the radius
ensure a rigid fixation
Olecranon fracture repair:
Why would you not insert distal screws into the radius in a young horse?
it may lead to subluxation of the elbow
Olecranon fracture repair:
Prognosis?
Good with ORIF - 68-87%
