Fracture

Question 1

What is the most common bone lesion?

Answer 1

Fracture

Question 2

What does formation of non-bone tissue at a fracture site represent?

Answer 2

Incomplete healing

Question 3

What are the three phases of fracture healing?

Answer 3

1. Inflammation
2. Reparative phase
3. Remodeling phase

Question 4

What is dead bone characterized by?

Answer 4

Absence of osteocytes and empty osteocyte lacunae

Question 5

What are the major events that occur in the inflammatory phase of fracture healing?

Answer 5

Large clot forms and pluripotential mesenchymal cells from soft tissue give rise to osteoblasts

Question 6

What are the two major objectives of the Reparative Phase of Fracture Healing?

Answer 6

1. Organize and resorb the blood clot
2. Neovascularize construction of the callus, which will eventually bridge the fracture site

Question 7

What is the objective of the remodeling phase of fracture healing?

Answer 7

The bone is reorganized so that the original cortex is restored

Question 8

In what conditions does primary healing of fractures occur?

Answer 8

In controlled fractures where there is no bone displacement or soft tissue injury (Surgery or Drill holes)

Question 9

What conditions does nonunion occur in fractures?

Answer 9

Interposition of soft tissue w/i the fracture, excessive motion, infection, poor blood supply

Question 10

What is pseudoarthrosis?

Answer 10

Joint-like tissue is formed at an unhealed fracture site

Question 11

What causes stress fractures?

Answer 11

Accumulation of stress-induced microfractures.

Question 12

What event occurs before a stress fracture?

Answer 12

Formation of a callus