bone injury and repair Flashcards
most important factor in fracture repair?
blood flow
fracture repair stages?
inflammation, repair, remodeling
type of callus for bone ends NOT in continuity?
bridging (SOFT) callus
effect of immobilization?
MORE immobilization, LESS callus
indicates completion of fracture healing?
marrow space repopulation
bone growth factors?
BMP-2, BMP-3, BMP-7
effect of NICOTINE?
increases time to heal, nonunion risk; decreases callus strength
effect of NSAIDS?
COX-2 required for enchondral ossification
effect of QUINOLONES?
toxic to chondrocytes, inhibit fracture healing
effect of ULTRASOUND?
accelerates fracture healing, increases callus strength
location of highest risk for pathologic fracture?
subtrochanteric femur
graft properties: Osteoconductive Matrix
scaffold for bone growth
graft properties: Osteoinductive Factors
stimulate bone formation (e.g. BMP)
graft properties: Osteogenic Cells
primitive mesenchyme, osteoblasts, osteocytes
types of ALLOGRAFT (non-self) bone?
fresh, fresh-frozen, freeze-dried
mechanism of allograft rejection?
cellular (T cell)
MOST IMMUNOGENIC cell component?
bone marrow
does not elicit immune response?
hydroxyapatite
5 stages of graft healing?
inflammation osteoblast differentiation osteoinduction osteoconduction remodeling
bone graft types?
cortical, cancellous, synthetic, Ca phosphate-based, Ca sulfate, CaCO3, Coralline hydroxyapatite, Silicate-based, Aluminum oxide
types of ossification in distraction osteogenesis?
optimal stability: intramembranous
unstable: enchondral
rate of distraction in distraction osteogenesis?
0.25mm, 3-4x/day (0.75-1mm/day)
heterotrophic ossification
ectopic bone in soft tissues (RT, THR, THR + Paget’s)
