Chapter 88 - Nonunions, Malunions, and Osteomyelitis

Question 1

Hypertrophic non-unions lack what?

Answer 1

stability!, growth factors are usually sufficient

Question 2

atrophic non-union definition

Answer 2

avascular or hypovascular bone ends

Question 3

treatment for atrophic non-union

Answer 3

must debride the non-viable ends of bone
then provide stability AND growth factors - eg bone graft

Question 4

osteoconductive

Answer 4

scaffold only

eg calcium sulfate

Question 5

osteoINductive

Answer 5

has the growth factors present

eg BMP

Question 6

osteoGENic

Answer 6

contains actual CELLS needed for bone formation

Question 7

what plane of motion are humeral malunions bet handled in?

Answer 7

sagittal plane (bc that is in the plane of motion)
- 20degrees of varus, valgus
- 30 degrees of pro/recurvatum acceptable
- 3cm shortening

Question 8

what plane of motion are lower extremity malunions best handled in?

Answer 8

pro/recurvatum (sagittal plane)

Question 9

rotational malalignment > what degree is considered a problem in the lower extremith?

Answer 9

15deg

Question 10

hematogenously spread osteomyelitis occurs where in the bone?

Answer 10

metaphyseal end plate arterioles

Question 11

biofilm consists of bacteria in what state?

Answer 11

sessile - markedly reduced metabolic rate -> inability for antibiotics to work

Question 12

how long does it take for a biofilm layer to form?

Answer 12

8-14 days

Question 13

differentiate sequestrum v involucrum

Answer 13

sequestrum - radiodense on XR

involucrum - walled off sequestrum surrounded by healthy new bone

Question 14

what is the latency phase in distraction osteogenesis?

Answer 14

5-10 days immediately post op to allow initial bone to form

Question 15

what is the ideal lengthening rate during the lengthening phase

Answer 15

1mm/d divided into 4 even times

Question 16

what is the phase following lengthening?

Answer 16

consolidation - allows remodeling of the bone transport