Mechanical Behavior Of Bone Flashcards
Bone is a type of __________ tissue
Connective
Bone = ____ + ___________ ____ (ECM)
Cells + Extracellular matrix (ECM)
What are the 3 types of bone cells?
Osteoblast
Osteocyte
Osteoclast
Osteoblast
Deposition; growth, repair, remodeling
Osteocyte
Maintenance
Osteoclast
Resorption; unloading, repair, remodeling (“Pacmen”)
Matrix composition of bone cells
Organic material
Matrix composition of bone Extracellular matrix
Organic
Inorganic
Remaining tissue volume: water
Bone ECM = organic material (__-___%)
30-35%
Bone ECM = inorganic material (__-___%)
65-70%
Organic material (2)
Protein
Vitamin C
Lack of organic material results in ______ bones
Brittle bones
Lack of organic material = brittle bones (_______)
Scurvy (found in sailors)
Inorganic material (2)
Calcium
Vitamin D
Lack of inorganic material results in ______ bones
Compliant
Lack of inorganic material = compliant bones (_______, _________)
Rickets, osteomalacia; “bending a lot, but not breaking”
Bone has both ______ and _______ mechanical behaviors.
Elastic; plastic
Elastic mechanical behavior
Deforms with initial load in linear rate
Elastic has 2 types of materials
Stiff materials
Compliant materials
Stiff materials (elastic mechanical behavior): _________ deformation with ______ load.
Less; more
Compliant materials (elastic mechanical behavior): _____ deformation with ______ load
More; less
Plastic mechanical behavior
At a given load, the bone yields and continues to deform without additional load.
2 types of plastic mechanical behavior
Brittle
Ductile
Brittle
Breaks with load
Ductile
Deforms with load
Glass is an example of what kind of mechanical behavior?
Stiff/brittle
Metal is an example of what kind of mechanical behavior?
Stiff/ductile (high load, won’t break)
Rubber is an example of what kind of mechanical behavior?
Compliant/Brittle (stretch it too much, breakage)
Putty is an example of what kind of mechanical behavior?
Compliant/ductile
Bone strength
Maximum load at the failure point
Bone stiffness or elasticity
Load required to deform the bone by a given amount
Slope of load-deformation curve
Toughness
Energy required to yield or fracture the bone; area under load-deformation curve
Draw load deformation curve
Bone strength
Elastic region, slope = stiffness
Area = toughness
Yield point (fracture begins)
Plastic region
Healthy bone (organic/inorganic)
30-35% organic
65-70% inorganic
Brittle bone (organic/inorganic)
Less organic
More inorganic
Compliant bone (organic/inorganic)
More organic
Less inorganic
Which of the following pathologies is associated with lack of inorganic material in bone?
Rickets/osteomalacia
