15- Fractures

Question 1

What are the 4 quesitons you must ask yourself to describe a fracture to match radiographic findings?

Answer 1

1. Which bone is broken?
2. What region or segment of the bone is broken?
3. What is the pattern of the break?
4. Is the skin broken?

Question 2

Where is the diaphysis?

Answer 2

shaft of long bone

Question 3

Where is the metaphysis?

Answer 3

region of bone right under the physis (growth plate)

Question 4

Where is the epiphysis?

Answer 4

region of bone across the physis just below the articular cartilage

Question 5

What is a fracture?

Answer 5

represents the failure of material (bone) to withstand a force

Question 6

What are the 3 factors that apply to fractures besides the inheritant properties of the bone?

Answer 6

Magnitude of the force applied to it, direction of that force, and the rate at which force is applied

Question 7

How does the magnitude of force relate to fractures?

Answer 7

mechanism of injury (how much energy is imparted to the bone) will influence if a fracture will occur

Question 8

What are the 3 types of forces that can act on the bone from different directions?

Answer 8

compressive (push), tensile (pull), or torsional (twist)

Question 9

What does it mean when we say the bone is “anidotrophic?”

Answer 9

its mechanical properties are dependent on the direction of loading

Question 10

If there is a perpendicular compression of the bone at the diaphysis, what side will break first?

Answer 10

side of the bone under the tension will fracture first and the fracture will move across to the compression side

Question 11

What does it mean when we say the bone is “viscoelastic?”

Answer 11

bones mechanical properties are dependent on the loading rate of an applied force

Question 12

Do low speeds or high speeds typically fracture bones?

Answer 12

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

Question 13

What is a comminuted fracture?

Answer 13

breaks with more than one fracture lines results in 2 or more bone fragments

Question 14

What is the MOI to cause comminuted fractures?

Answer 14

• Comminuted fracture implies a high energy mechanism of injury
• Can also happen result from low energy injury to a bone weakened from disease

Question 15

What is a transverse fracture?

Answer 15

fracture that occurs at an angle perpendicular to the shaft of the bone

Question 16

What is an oblique fracture?

Answer 16

crosses the bone diagonally from one cortex to the other

Question 17

What is a spiral fracture?

Answer 17

wraps around the bone like a coil, by a twisting force results in a spiral shaped fracture line about the bone

Question 18

What are avulsion fractures?

Answer 18

can occur where the ligament pulls the bone away from the surrounding bone due to application of force external to the body

Question 19

What are open fractures?

Answer 19

fracture associated with breaks in the skin

Question 20

When is a open fracture suspected?

Answer 20

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

Question 21

Why are open fractures medical emergencies?

Answer 21

• 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

Question 22

What is “ductility”?

Answer 22

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

Question 23

What is a torus (buckle) Fx?

Answer 23

occurs when the bone under load bends but does not break

Question 24

Buckle and greenstick fractures are common in what population?

Answer 24

children

Question 25

What isa greenstick fracture?

Answer 25

occurs when forces applied to young bone break it through only one cortex but not completely across

Question 26

What is primary bone healing?

Answer 26

the deposition of new bone across the fracture by osteoblasts

Question 27

What is the physiological process to primary bone healing?

Answer 27

• 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

Question 28

What is secondary bone healing?

Answer 28

bone first produces a mass of cartilage scar. The mass ossifies and then remodels to form normal bone

Question 29

What is the physiological process to secondary bone healing?

Answer 29

• 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

Question 30

True or False: Assessing musculoskeletal emergencies is paramount to maintaining proper ABC’s.

Answer 30

False

Question 31

What is a pathological fracture?

Answer 31

a fracture of bone weakened by disease or tumor

Question 32

What is reduction?

Answer 32

realigning displaced fractures

Question 33

What does ORIF stand for?

Answer 33

stands for open reduction and internal fixation

Question 34

What are the problems with ORIF?

Answer 34

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)

Question 35

What is stress shielding?

Answer 35

rigid fixation (ORIF) of the bone prevents the fracture line from experiencing and responding to loading stresses

Question 36

What is wolff’s law?

Answer 36

bone grows in response to mechanical stress

Question 37

What are the 5 rules of Fx care?

Answer 37

1. 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)
2. Ensure that there is good perfusion (ie release compartments with elevated pressure loosen air casts)
3. Align bone (which may help with perfusion)
4. 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)
5. Be mindfull of the growth plate if present it is weaker than the surrounding bone and injuries to it may lead to growth disturbances

Question 38

When will X-ray show bone healing after an injury?

Answer 38

X-ray will start to reveal bone healing typically 6 weeks after injury

Question 39

What occurs in the displaced alignment on an X-ray?

Answer 39

a Fx in which the fragments are no longer in their usual alignment

Question 40

What occurs in the angulated alignment on an X-ray?

Answer 40

A Fx in which the fragments are malaligned at an angle to one another

Question 41

Who is at risk for a venous thrombis formation?

Answer 41

patient with a lower extremity fracture is at risk for venous thrombus

Question 42

Why is prophylaxis agents against thrombus offered to patients with lower extremity fractures?

Answer 42

PE’s might develop

Question 43

What is fat embolism syndrome?

Answer 43

can develop as fatty marrow exposed at the fracture site is carried in the bloodstream and circulates to the lungs

Question 44

What are the Sx of fat embolism syndrome?

Answer 44

respiratory compromise, change in mental status and a petechail rash