Bone Density ARRT Examination
Review Questions with Solutions
Osteroporosis - -A skeletal disorder characterized by compromised bone
strength predisposing a person to an increased risk of fracture. Defined by
World Health Organization (WHO) based on bone mineral density (BMD)
assessment BMD lies 2.5 standard deviations or more below average value
for young healthy women, T-score <-2.5 SD
Occurs when rate of bone resorption exceeds rate of bone
formation=decrease in bone mass.
-World Health Organization (WHO) - -- In 1994, the WHO selected a BMD
cut-point for defining the prevalence of osteoporosis in the Caucasian post-
menopausal female population.
- T score <-2.5 SD is considered Osteoporosis
-Four categories of WHO: - -
-"WHO 8" - -Clinical risk factors for fx age, low bone mass index, prior fx,
parental hip fx, current smoker, glucocorticoid use (3 mo), rheumatoid
arthritis, excessive alcohol consumption
-Primary Osteoporosis - -Metabolic bone disease characterized by low bone
mass & deterioration of bone tissue=bone fragility and increased fx risk no
direct or singular cause
Type 1= post menopausal osteoporosis (estrogen loss)
Type 2=age related osteoporosis
-Two Types of Primary Osteoporosis: - -Two types: Idiopathic
- Type I: Bone loss occurs in trabecular part of
bone; menopause
- Type II: Cortical bone; aging process
-Primary Osteoporosis Risk Factors: - -1. Age: increases with age
2. Genetics: runs in the family
3. Sex: females have accelerated bone loss after menopause
4. Hormones: estrogen deficiency results in accelerated bone loss
5. Nutritional: inadequate vitamin D, calcium
6. Physical activity: inactivity promotes osteoporosis
7. Environmental factors: smoking, alcohol promote osteoporosis
-Secondary Osteoporosis - -Secondary to or caused by something else =
direct cause result from variety of chronic conditions that significantly
contribute to bone mineral loss, or result from effects of medications &
,nutritional deficiencies. Such as hyperparathyroidism, long-term drug
therapy, long-term immobility.
-Support - -Function for framework for attachment of muscles & tissues
-Protection - -Function to protect internal organs from injury
-Movement - -Function for bones act as levers & attachment for muscles
-Mineral Storage - -Function as reservoir for Ca and phosphorus, essential
for cellular activities
-blood cell production - -Function where hematopoiesis occurs in red
marrow found w/in bone cavities
-Energy Storage - -Function where lipids (fats) stored in adipose cells of
yellow marrow serve as an energy reservoir
-Trabecular bone - -- *20%* of skeletal body mass
- Spongy/honeycomb, *CANCELLOUS*
- Supports compressive loads
- *AXIAL* skeleton
- Most responsive to therapy
- Higher metabolic rate
- End of long bones
-Cortical bone - -- *80%* of skeletal body mass
- *COMPACT*, strong, dense
- Resists twisting and bending motion
- *APPENDICULAR* skeleton
- Shaft of long bones
-Three functions of the skeleton: - -- Protect vital organs
- Scaffolding for the musculoskeletal system
- Manufactures red blood cells
-Axial skeleton includes: - -Primarily trabecular bone. Skull, vertebral
column, sternum and ribs.
-Appendicular skeleton includes: - -Primarily cortical bone. Scapula,
extremities and pelvic girdle.
-Bone - -Structural anatomy is for weight bearing & non-weight bearing.
-Weight-bearing includes: - -Lower extremities, spine, calcaneus, and
portions of the pelvic girdle.
, -Non-weight bearing includes: - -The remainder of the skeleton
-Cortical sites include: - -Total body, femoral neck, fingers, proximal
forearm and distal forearm.
-Trabecular sites include: - -Spine, Ward's area (3 bundles of trabecular
bone in femoral neck area), calcaneus, and ultra distal forearm.
-Central sites include: - -- Thoracic and lumbar spine (spine-trabecular,
weight bearing and axial)
- Proximal femur
-Peripheral sites include: - -- Forearm- DXA,SXA, pQCT
- Heel - SXA, QUS
- Fingers - DXA, regular x-ray
- Tibia - QUS
-Functions of bones: - -Support
Protection
Movement
Mineral Storage
Blood cell production
Energy storage
-Bone is composed of - -- Bone forming cells (osteoblasts and osteocytes)
- Bone resorbing cells (osteoclasts)
- Nonmineral matrix of collagen and noncollagenous protein (osteoid)
- Inorganic mineral salts deposited within the matrix
-Calcaneous - -Example of WB , appendicular, peripheral, trabecular site
-Femoral neck - -Example of WB, appendicular, central, cortical site
-Lumbar spine - -Example of WB, axial, central, trabecular site
-Osteoclasts - -Live in the central portion of the bone. Responsible for
resorption, dissolve mineral and digest bone matrix.
Osteoclast activity in women increases due to the decrease in estrogen after
menopause
Men with prematurely decrease in testosterone may have increase in
osteoclast activity.
-Osteoblasts - -Responsible for bone formation. Main function is to
synthesize bone matrix.
Review Questions with Solutions
Osteroporosis - -A skeletal disorder characterized by compromised bone
strength predisposing a person to an increased risk of fracture. Defined by
World Health Organization (WHO) based on bone mineral density (BMD)
assessment BMD lies 2.5 standard deviations or more below average value
for young healthy women, T-score <-2.5 SD
Occurs when rate of bone resorption exceeds rate of bone
formation=decrease in bone mass.
-World Health Organization (WHO) - -- In 1994, the WHO selected a BMD
cut-point for defining the prevalence of osteoporosis in the Caucasian post-
menopausal female population.
- T score <-2.5 SD is considered Osteoporosis
-Four categories of WHO: - -
-"WHO 8" - -Clinical risk factors for fx age, low bone mass index, prior fx,
parental hip fx, current smoker, glucocorticoid use (3 mo), rheumatoid
arthritis, excessive alcohol consumption
-Primary Osteoporosis - -Metabolic bone disease characterized by low bone
mass & deterioration of bone tissue=bone fragility and increased fx risk no
direct or singular cause
Type 1= post menopausal osteoporosis (estrogen loss)
Type 2=age related osteoporosis
-Two Types of Primary Osteoporosis: - -Two types: Idiopathic
- Type I: Bone loss occurs in trabecular part of
bone; menopause
- Type II: Cortical bone; aging process
-Primary Osteoporosis Risk Factors: - -1. Age: increases with age
2. Genetics: runs in the family
3. Sex: females have accelerated bone loss after menopause
4. Hormones: estrogen deficiency results in accelerated bone loss
5. Nutritional: inadequate vitamin D, calcium
6. Physical activity: inactivity promotes osteoporosis
7. Environmental factors: smoking, alcohol promote osteoporosis
-Secondary Osteoporosis - -Secondary to or caused by something else =
direct cause result from variety of chronic conditions that significantly
contribute to bone mineral loss, or result from effects of medications &
,nutritional deficiencies. Such as hyperparathyroidism, long-term drug
therapy, long-term immobility.
-Support - -Function for framework for attachment of muscles & tissues
-Protection - -Function to protect internal organs from injury
-Movement - -Function for bones act as levers & attachment for muscles
-Mineral Storage - -Function as reservoir for Ca and phosphorus, essential
for cellular activities
-blood cell production - -Function where hematopoiesis occurs in red
marrow found w/in bone cavities
-Energy Storage - -Function where lipids (fats) stored in adipose cells of
yellow marrow serve as an energy reservoir
-Trabecular bone - -- *20%* of skeletal body mass
- Spongy/honeycomb, *CANCELLOUS*
- Supports compressive loads
- *AXIAL* skeleton
- Most responsive to therapy
- Higher metabolic rate
- End of long bones
-Cortical bone - -- *80%* of skeletal body mass
- *COMPACT*, strong, dense
- Resists twisting and bending motion
- *APPENDICULAR* skeleton
- Shaft of long bones
-Three functions of the skeleton: - -- Protect vital organs
- Scaffolding for the musculoskeletal system
- Manufactures red blood cells
-Axial skeleton includes: - -Primarily trabecular bone. Skull, vertebral
column, sternum and ribs.
-Appendicular skeleton includes: - -Primarily cortical bone. Scapula,
extremities and pelvic girdle.
-Bone - -Structural anatomy is for weight bearing & non-weight bearing.
-Weight-bearing includes: - -Lower extremities, spine, calcaneus, and
portions of the pelvic girdle.
, -Non-weight bearing includes: - -The remainder of the skeleton
-Cortical sites include: - -Total body, femoral neck, fingers, proximal
forearm and distal forearm.
-Trabecular sites include: - -Spine, Ward's area (3 bundles of trabecular
bone in femoral neck area), calcaneus, and ultra distal forearm.
-Central sites include: - -- Thoracic and lumbar spine (spine-trabecular,
weight bearing and axial)
- Proximal femur
-Peripheral sites include: - -- Forearm- DXA,SXA, pQCT
- Heel - SXA, QUS
- Fingers - DXA, regular x-ray
- Tibia - QUS
-Functions of bones: - -Support
Protection
Movement
Mineral Storage
Blood cell production
Energy storage
-Bone is composed of - -- Bone forming cells (osteoblasts and osteocytes)
- Bone resorbing cells (osteoclasts)
- Nonmineral matrix of collagen and noncollagenous protein (osteoid)
- Inorganic mineral salts deposited within the matrix
-Calcaneous - -Example of WB , appendicular, peripheral, trabecular site
-Femoral neck - -Example of WB, appendicular, central, cortical site
-Lumbar spine - -Example of WB, axial, central, trabecular site
-Osteoclasts - -Live in the central portion of the bone. Responsible for
resorption, dissolve mineral and digest bone matrix.
Osteoclast activity in women increases due to the decrease in estrogen after
menopause
Men with prematurely decrease in testosterone may have increase in
osteoclast activity.
-Osteoblasts - -Responsible for bone formation. Main function is to
synthesize bone matrix.
