Fractures Flashcards
what do compression fractures look like?
what do tension fractures look like?
what do shear fractures look like?
what do bending fractures look like?
what do torsion fractures look like?
what are simple vs complex forces?
simple:
-compression
-tension
-shear
complex:
-bending
-torsion
what, generally, causes a fracture to occur?
- Occurs when load on bone exceeds the strength of the bone
Extrinsic forces:
* External forces acting on bone
> Cause the majority of fractures
Intrinsic forces
* Internal forces (tendon pull…)
> Less frequent, leads to specific fractures
how do we desribe a fracture (6 things)
- Bone involved
- Location within the bone
* Epiphyseal, Physeal, Metaphyseal, Diaphyseal
* Proximal, Middle, Distal - Fracture type or complexity
* Simple, Comminuted, Segmental - Fracture configuration
* Transverse
* Oblique (Short, Long)
* Spiral
* Wedge - Fracture characteristic
* Open, Closed - Displacement
simple vs comminuted fracture, and when does each occur
Simple:
-single fracture line
-Low energy trauma
-Minimal soft tissue trauma
Comminuted:
-multiple intersecting fracture lines
-High energy trauma
-High soft tissue damage
how do we desribe the segmental fracture configuration
- Segmental: multiple, non intersecting fracture lines
what is a transverse fracture, when does it occur
- Fracture line perpendicular to the long axis of bone
- Tensile loading
- Fracture angle 90° > x > 60° relative to long axis
what is an oblique fracture and what is short vs long? when do they occur?
- Short oblique: Fracture angle 60° > x > 30° relative to long axis
- Long Oblique: Fracture angle x <30° relative to long axis
- Compression loading
what causes a spiral fracture
- Torsional forces
- “Figure-of-eight” fracture line
- Very similar to a long oblique Fx
- One of the easiest fractures to get
> Playing…
when do we see a wedge fracture and what does its character depend on?
- Result from bending forces
- Size of wedge depends on loading
- Biomechanically important
when should we fix a fracture
as early as possible
advantages to early, accurate fixation
- Reduces pain
- Allows early return to function
- Reduces risk of non-union
- Eliminates risk of mal-union
Goals of fracture fixation:
Early ambulation and complete return to function
what are the categories of primary bone healing?
-Contact Healing
-Gap Healing
what are the properties of Primary Bone Healing – Contact Healing
- Absolute stability (< 2% strain)
- No or minimal gap (< 0.01mm)
- Bone heals without the formation of callus
- Weaker than 2* bone formation initially
- Slow process…
what are the properties of Primary Bone Healing – Gap Healing
- Absolute stability (< 2% strain)
- Small gap (< 1mm)
- Initial fibrin matrix with angiogenesis
- Within days-weeks lamellar bone fills gap
> Initially oriented perpendicular to long axis – weak
> 3-4 weeks > reoriented
what are the properties of secondary (indirect) bone healing? what is the proccess?
- Adequate stability
- Some gap may be present
- Formation of callus
- Transformation of tissue into another until bone is repaired
> Granulation
> Fibrous tissue
> Fibrocartilage
> Bone - Clinical union is relatively fast
5 steps of secondary bone healing
- Inflammation
- Intramembranous Ossification
- Soft Callus (chondrogenesis)
- Hard Callus (endochondral ossification)
- Bone Remodeling
fixation methods for broken bone
- Splint/Cast (coaptation)
- Intramedullary (IM) pin
- Cerclage wire
- Bone plate
- External fixator
- Interlocking nail
- Often used in COMBINATIONS!
how should casts be placed to help heal a fracture? when should they not be used?
- Must immobilize joint above and (all) joints below
- Cannot be used for upper extremities (femur, humerus)
- Some bones should not be casted (radius in miniature breeds)
