Fracture class and assessment (Lewis) Flashcards
1
Q
Strength of bone dependent on
A
- material properties
- structural properties
- rate of load applied
- viscoelastic
- Orientation of applied load
- anisotropic
2
Q
Wolf’s law
A
Bone will form in response to forces it’s subject to
3
Q
Fracture mechanics
Types of stress
A
- Tension
- attachments of ligments or tendons
- Compression
- aka: axial loading
- Shear
- think of it as eccentric loading (making a parallelogram out of a box)
- Bending
- Torsion
4
Q
Tension
A
- Produces elongation
- Creates avulsion fractures
- Occurs at apophyses - traction physes (immature dogs)
- olecranon
- Calcaneus
- tibial tuberosity
5
Q
Compression
A
- Opposite force of tension
- Not a common type of fracture
- can happen in vertebral bodies (cancellous bone)
- Tends to create short oblique fractures
- Bone is strongest in this mode of loading
6
Q
Shear
A
- Eccentric loading of a bone’s surface
- Bone is weakest in this mode of loading
- lateral condylar fracture (when small dog jumps out of arms)
7
Q
Bending
A
- Results in compressive and tensile forces
- Causes short transverse or short oblique fractures
- often with butterfly thingy
- Fracture initiates on tension surface
8
Q
Torsion
A
- Rotational forces applied along long axis of the bone
- Results in spiral fractures
9
Q
Descriptive fracture classification
Important because
A
- Good communication
- Complexity
- Equipment
- Prognosis
- Concurrent injuries
- Systemic dz
- Cost
10
Q
Configuration
Incomplete fractures
A
- Greenstick: opposing cortices involved
- young animals
- bending or torsional forces
- can be oblique or spiral fractures
- Fissure: involves only one cortex
11
Q
Configuration
Complete fractures
A
- Continuity of bone is disrupted
- Transverse
- Oblique
- Spiral
- Comminuted
- Segmental
12
Q
Transverse fractures
*what force would bone be stable to if anatomically reduced?
A
- propagates perpendicular to bone’s long axis
- smooth or serrated fracture surfaces
- generally result of bending forces
- Some inherent stability
- Stable to
- shear forces
13
Q
Oblique fracture
A
- Fracture line rund diagonally to bone’s long axis
- opposing fracture surfaces (cortices) are in same plane
- generally result of axial compression and bending nforces
- limited inherent stability: would succumb to all forces if reduced
14
Q
Spiral fracture
A
- Fracture line runs diagonally to bone’s long axis
- Opposing fracture surfaces (cortices) are in different planes
- Generally result of torsional forces
- Inherently stable if reduced
15
Q
Comminuted fractures
A
- At least three fracture segments
- Fracture lines intersect
- High(er) energy trauma
- Multiple forces involved
*think about damage to all the soft tissue when you see this: KE=1/2mv2