Radiography

Question 1

Radiodensity

Answer 1

tissue density determines penetrance

Question 2

Radiopaque

Answer 2

relative impenetrability to X-rays

Question 3

Radiolucent

Answer 3

relative penetrability to X-rays

Question 4

Metaphysis

Answer 4

transitional zone at which the diaphysis and epiphysis of a bone come together. Thickening section of bone.

Question 5

diaphysis

Answer 5

the shaft of a long bone

Question 6

epiphyseal plate

Answer 6

a hyaline cartilage plate in the metaphysis at each end of a long bone. Ossifies with age.

Question 7

epiphysis

Answer 7

The end of a long bone that is originally separated from the main bone by a layer of cartilage but later becomes united to the main bone through ossification

Question 8

apophysis

Answer 8

an expanded or projecting part (of a bone–i.e. the point of the elbow)

Question 9

Always get ______ views of X-ray

Answer 9

perpendicular

Question 10

Fracture

Answer 10

radiolucent (fluid, air, etc.) a complete disruption in the continuity of a bone.

Always get two views.

Question 11

indirect signs of a fracture

Answer 11

soft-tissue swelling, obliteration or displacement of fat stripes, periosteal and endosteal reaction, buckling of the cortex, double cortical line

Question 12

when you break a bone, what swelling happens/is visble?

Answer 12

hemearthrosis

Question 13

periosteal vs. endosteal reactions

Answer 13

Periosteal reaction is the formation of new bone in response to injury or other stimuli of the periosteum surrounding the bone.

Endosteal reaction is the formation of new bone on the inside (endosteal side) of the bone.

Question 14

compound fracture

Answer 14

breaks the skin

Question 15

Displacement

Answer 15

movement away from the midline, but not angulated

Question 16

Angulation

Answer 16

one end of the bone moves away from the midline and the other does not.

Question 17

Valgus vs. Verus

Answer 17

Valgus = knock-knee; Verus = bowed

Question 18

X-rays provide _____ evidence of a ligamentous injury

Answer 18

indirect

Question 19

Intramembranous ossification

Answer 19

mineralization of connective tissue

Question 20

Endochondral ossification

Answer 20

mineralization of cartilage

Question 21

Woven bone vs. Lamellar bone

Answer 21

WB: immature bones, rapid deposition.

LB: mature bone, slower deposition.

Question 22

First stage of bone healing

Answer 22

inflammatory phase.

Hemarthosis;

Damage to blood vessels leads to osteocyte death, necrotic material at the fracture site.

Question 23

inflammatory phase**

Answer 23

fibroblast, osteoblasts, and chondrocytes appear and produce new matrix

Question 24

monocytes and fractures

Answer 24

Monocytes → Osteoclasts which resorb necrotic tissue

Question 25

Second phase of fracture healing

Answer 25

**soft callous **

pluripotent mesenchymal cells –> osteoblasts, chondrocytes, fibroblasts.

Question 26

pluipotent mesenchymal cells become what?

Answer 26

osteoblasts, chondrocytes, fibroblasts

Question 27

soft callous looks like what on an x-ray

Answer 27

fracture

no radiopaque caclium yet

Question 28

Third stage of bone healing

Answer 28

Hard callus

Intramembranous bone formation at periphery

Woven bone envelopes fracture ends and becomes ossified. Both intramembranous and endochondral ossification involved in the maturing callus.

Question 29

Advantages of External Callus

Answer 29

The ability of a structure to resist torsional and bending loads is proportionate to R4

Question 30

clinical union* definition

Answer 30

fracture site becomes stable and pain free

Question 31

Radiographic union *

Answer 31

plain radiographs show bone trabeculae or cortical bone crossing the fracture site

Question 32

Fourth stage of bone healing

Answer 32

Replacement of woven bone by lamellar bone

Resorption of unneeded callus may continue for years!

Question 33

Variables that Influence Fracture Healing

Answer 33

Injury variables (damage to blood supply, compound, infection)

Patient variables (age)

Tissue variables (location of the bone, bone disease)

Treatment variables (apposition (proximity) of fracture fragments)

Question 34

Fracture Repair After Internal Plate Fixation

Answer 34

Fracture fixation causes no formation of external callus **Lamellar bone forms** (slow healing) directly across fracture line

Question 35

What are the three zones of bone healing and what direction* does it occur in?

Answer 35

metaphysis, hypertrophic zone–weakest zone, proliferative zone. So maturation occurs **distal to proximal**

Question 36

If you fracture the proliferative zone…

Answer 36

increased risk of…

growth arrest

and

poor healing