15- Fractures Flashcards
What are the 4 quesitons you must ask yourself to describe a fracture to match radiographic findings?
- Which bone is broken?
- What region or segment of the bone is broken?
- What is the pattern of the break?
- Is the skin broken?
Where is the diaphysis?
shaft of long bone
Where is the metaphysis?
region of bone right under the physis (growth plate)
Where is the epiphysis?
region of bone across the physis just below the articular cartilage
What is a fracture?
represents the failure of material (bone) to withstand a force
What are the 3 factors that apply to fractures besides the inheritant properties of the bone?
Magnitude of the force applied to it, direction of that force, and the rate at which force is applied
How does the magnitude of force relate to fractures?
mechanism of injury (how much energy is imparted to the bone) will influence if a fracture will occur
What are the 3 types of forces that can act on the bone from different directions?
compressive (push), tensile (pull), or torsional (twist)
What does it mean when we say the bone is “anidotrophic?”
its mechanical properties are dependent on the direction of loading
If there is a perpendicular compression of the bone at the diaphysis, what side will break first?
side of the bone under the tension will fracture first and the fracture will move across to the compression side
What does it mean when we say the bone is “viscoelastic?”
bones mechanical properties are dependent on the loading rate of an applied force
Do low speeds or high speeds typically fracture bones?
when force is applied at low speeds bone is weaker than ligament, and when the force is applied at high speeds bone is stronger than ligament
What is a comminuted fracture?
breaks with more than one fracture lines results in 2 or more bone fragments
What is the MOI to cause comminuted fractures?
- Comminuted fracture implies a high energy mechanism of injury
- Can also happen result from low energy injury to a bone weakened from disease
What is a transverse fracture?
fracture that occurs at an angle perpendicular to the shaft of the bone
What is an oblique fracture?
crosses the bone diagonally from one cortex to the other
What is a spiral fracture?
wraps around the bone like a coil, by a twisting force results in a spiral shaped fracture line about the bone
What are avulsion fractures?
can occur where the ligament pulls the bone away from the surrounding bone due to application of force external to the body
What are open fractures?
fracture associated with breaks in the skin
When is a open fracture suspected?
all fractures associated with blood on the skin, even without obvious break in the skin, must be considered open unless and until another explanation for the blood is found
Why are open fractures medical emergencies?
- Open fractures are medical emergencies because if open fractures are not cleaned out surgically there is an increased risk of bone infection
- Classification of open fracures deals with the amount of soft tissue damage the more extensive the soft tissue damage the more emergent the open fracture
What is “ductility”?
The ability to float in ponds, eat bread crumbs, and take pictures of yourself in the mirror for facebook by flattening your lips and making sure your chest is in frame.
Also, it’s the property of greater plastic deformation before failure
What is a torus (buckle) Fx?
occurs when the bone under load bends but does not break
Buckle and greenstick fractures are common in what population?
children
What isa greenstick fracture?
occurs when forces applied to young bone break it through only one cortex but not completely across
What is primary bone healing?
the deposition of new bone across the fracture by osteoblasts
What is the physiological process to primary bone healing?
- New bone integrates into two opposing sides through tunnels creasted by osteoclasts called cutting cones
- In the cutting cone there is local bone reabsorption and ecentuall recreation of normal bone structure
- Requires precise reapproximation of the fracture and is rare in nature
- Requires rigid immobilization of the fracture as seen with surgical platting and compression of the cortices of the bone together
- Almost never occurs without surgical intervention
What is secondary bone healing?
bone first produces a mass of cartilage scar. The mass ossifies and then remodels to form normal bone
What is the physiological process to secondary bone healing?
• Bone breaks and a hematoma if formed
• Through the process of inflamm and angiogenesis the hematoma becomes organized
o Hematoma is the initial mechanical scaffolding and depot of biological factors that initiate and sustain development of bone
• Cells proliferate and granulation tissue (primitive scar) is formed
• Cartilaginous tissue is then calcified
• Blood vessels then invade bringing cellular machinery of bone remodeling and the calcified callus is converted to normal bone
• Periosteum is the main source of cells during healng process
True or False: Assessing musculoskeletal emergencies is paramount to maintaining proper ABC’s.
False
What is a pathological fracture?
a fracture of bone weakened by disease or tumor
What is reduction?
realigning displaced fractures
What does ORIF stand for?
stands for open reduction and internal fixation
What are the problems with ORIF?
it strips the Periosteum meaning that the surgeon must surgically expose the bone to secure a plate along a fracture, which increases the risk that bone won’t heal correctly and that infection will develop (periosteum is the main source of cells during healing)
What is stress shielding?
rigid fixation (ORIF) of the bone prevents the fracture line from experiencing and responding to loading stresses
What is wolff’s law?
bone grows in response to mechanical stress
What are the 5 rules of Fx care?
- Ensure that the fracture is surrounded by healthy soft tissue envelope (ie debride open wounds and maintain soft tissue coverage but do not cut the skin unnecessarily)
- Ensure that there is good perfusion (ie release compartments with elevated pressure loosen air casts)
- Align bone (which may help with perfusion)
- Ensure that just the right amount of load is applied (ie just enough to stimulate bone growth but not enough that gross motion leading to non-union is allowed)
- Be mindfull of the growth plate if present it is weaker than the surrounding bone and injuries to it may lead to growth disturbances
When will X-ray show bone healing after an injury?
X-ray will start to reveal bone healing typically 6 weeks after injury
What occurs in the displaced alignment on an X-ray?
a Fx in which the fragments are no longer in their usual alignment
What occurs in the angulated alignment on an X-ray?
A Fx in which the fragments are malaligned at an angle to one another
Who is at risk for a venous thrombis formation?
patient with a lower extremity fracture is at risk for venous thrombus
Why is prophylaxis agents against thrombus offered to patients with lower extremity fractures?
PE’s might develop
What is fat embolism syndrome?
can develop as fatty marrow exposed at the fracture site is carried in the bloodstream and circulates to the lungs
What are the Sx of fat embolism syndrome?
respiratory compromise, change in mental status and a petechail rash
