Lecture 10: Bones, Falls and Fractures Flashcards
What is the outer layer of bone?
What is the inner layer of bone?
Outer = Compact bone Inner = Spongy or Cancellous
What is Spongy/Trabecular/Cancellous bone
It is one of the two types of bone tissue found in the body. It is very porous and contains red bone marrow, where blood cells are made. It is weaker and easier to fracture than cortical bone.
What are the 3 factors affecting bone strength
- Bone density
- Bone quality
- Bone geometry
What is bone density?
Accounts for what percentage of bones resistance to fracture
What is the estimated rate of bone loss after menopause?
- Bone density is the mass of bone per unit of volume
- 50-80%
- 1% and 2% per year for the first 10 years and later a decline in less than .3-.5%/year
What is bone quality
Structural material from which bone is constructed
What are the 2 major components that increase the structural integrity of bone
- Collagen
2. Minerals
What are the major mineral in order of quantity and what do they provide
- Calcium
- Magnesium
- Sodium
- Potassium
Provide rigidity and strength
With aging collagen and minerals in our bones becomes __________ to mechanical loading
With aging collagen and minerals in our bones becomes less resistance to mechanical loading
What is bone geometry
As we age the diameter of our bones changes and this affects out bones strength
In OA the loss of BMD is compensated by a process called __________ which is_______?
In OA the loss of BMD is compensated by a process called periosteal deposition which is the addition of tissue along the outer surface of the bone
True or False: For the same bone thickness, the bone with the greater diameter is more solid vs. smaller diameter
True
What is the roof trusses and bone
A comparison of normal, osteoporotic and trained bone matrix
What is normal bone analogous to
A standard roof truss - healthy trabecular bone
What is osteoporosis bone analogous to
Roof truss with structural bracing missing. reduction in the number and size of bridges and the increase in resorption cavities which reduce bone strength.
Inc space in cavities
Dec size
Dec in # of bridges
What is trained bone matrix analogous to
Roof truss with added bracing for greater strength
Inc in size
Inc # of bridges
Dec space in cavities
The strength of bone is affected by more than its density. It is also affected by the ______ and ______ of the bones framework. Training can affect all 3 factors
The strength of bone is affected by more than its density. It is also affected by the Geometry and Integrity of the bones framework. Training can affect all 3 factors
What is osteopenia
A condition characterized by lower than normal bone density; may be the precursor for osteoporosis
-1 - -2.5 SD below the mean
What is osteoporosis
A disease where bone mass and structure decline to a point where there is significant increase in fragility and susceptibility to fracture
less than or equal to -2.5 SD below the mean
What is established osteoporosis
Those with osteoporosis and one or more fragility fractures
OA suffering hip fractures often experience a loss of independence; less than _______ of those who fracture their hips recover sufficiently to perform basic ADLs
OA suffering hip fractures often experience a loss of independence; less than 1/3 of those who fracture their hips recover sufficiently to perform basic ADLs
What percentage of woman sustain a fracture during their life time
40%
What are the 3 most common sites for fractures
- Hip
- Wrist
- Spine (compression)