Hoffman's lectures

Question 1

what does radiopaque and radiolucent mean?

Answer 1

radiopaque = relative impenetrability of x-rays, shows up lighter
radiolucent = relative penetrability of x-rays, shows up dark

Question 2

what is a fracture

Answer 2

complete disruption of the continuity of bone

Question 3

what are the indirect signs of a fracture

Answer 3

1. soft tissue swelling
obliteration of fat stripes 
periosteal and endosteal reaction
buckling of the cortex
double cortical line

Question 4

what does fat pad displacement look like

Answer 4

sails on either side of bone

Question 5

what does periosteal reactions look like?

Answer 5

bone growth on the side

Question 6

difference between lamellar and woven bone

Answer 6

woven bone is immature and quickly laid down and is replaced by lamellar bone which is stronger and mature

Question 7

cells important in healing of bone fracture and where they come from

Answer 7

osteoclasts, chondrocytes and fibroblasts come from mesenchymal cells
osteoclasts come from monocytes and are not involved in callus formation

Question 8

Difference between clinical union and radiographic union

Answer 8

clinical union is when the fracture becomes stable and pain free
radiographic union is when plain radiographs show bone over the fracture site

Question 9

which way does bone maturation occur

Answer 9

Distal to proximal