Test #4 Flashcards
Normal bone density & structure depends on what?
Normally functioning bone cells in adequate numbers
Normal endocrine balance
Normal nerve & stress timulators
Adequate dietary intake, normal intestinal absorption, & urinary excretion of vit. D, Ca, & P
At what age approx. does bone mass begin to decline?
35 yrs old
What % of bone loss occurs per decade in males? females?
3%; 8%
How can normal progressive bone atrophy be modified?
Anabolic gonadal hormones
Adrenal gluco-corticoids
Diet, exercise, heredity
Most metabolic, endocrine & nutritional disorders are charac. radiographically by what?
Increased bone production (osteosclerosis)
Increased bone resorption (osteopenia)
Inadequate bone mineralization w/ equilibrium in rate of resorption & production
What % of bone loss is required to see loss of density on xray?
30%
How thick should the cortex be compared to the overall diameter of the midpoint of a normal bone?
Cortical thickness should be roughly 1/2 the overall diameter of midpoint of a given bone
What bone is frequently used for the cortical thickness measurement to obtain an index of bone mass?
2nd or 3rd metacarpal
Increased radiolucency of bone or poverty of bone
Osteopenia
What are the M/C causes of osteopenia?
Osteoporosis
Osteomalacia (increase of uncalcified osteoid)
Hyperparathyroidism
Infiltrative diseases
M/C causes of diminished bone density in the vertebrae
Involutional osteoporosis Steroid effect (Cushing's Syndrome) Multiple Myeloma Hyperparathyroidism Leukemia Hemoglobinopathies Osteomalacia
What are the M/C causes of loss of bone density in children?
Leukemia Steroid therapy Cushing's syndrome Osteogenesis imperfecta tarda Idiopathetic juvenile osteopororsis Still's disease Thyrotoxicosis Liver disease Turner's syndrome Paralysis
A skeletal condition in which the quantity of bone is decreased in amount but is normal in composition (quality). Freq. assoc. w/ structural failure
Osteoporosis
What is the M/C encountered metabolic disease of bone?
Osteoporosis
Type of osteoporosis that involves the major portion of the skeleton especially the axial components
Generalized osteoporosis
Type of osteoporosis that is confined to an area or segment of hte body i.e. a limb (Sudecks Atrophy)
Regional osteoporosis
Type of osteoporosis that is a focal loss of bone density involving a small portion of a bone. Examples include tumors & arthritis.
Localized osteoporosis
M/C causes of generalized osteoporosis
Senescent (senile)
Postmenopausal
(AKA Involutional osteoporosis)
Involutional osteoporosis (Senile/postmenopausal) may result from what?
Osteoblastic inactivity & excessive bone resorption
Lack of gonadal hormones necessary for osteoblastic activity
Deficiency of proteins
Inadequate diet & activity
What is the M/C complaint assoc. w/ generalized osteoporosis?
Back pain
What are the most freq. complications which precipitate pain & disability assoc. w/ osteoporosis?
Fxs of the vert. bodies, hips, wrists, ribs, pubic rami, humerus, sacrum
Decrease in height secondary to decrease in vertebral body height producing a kyphosis & spinal rigidity
What are lab features assoc. w/ osteoporosis?
Serum Ca & Alk Phos are normal
Urinary hydroxyproline levels may be elevated
Iatrogenic osteoporosis includes what types?
Heparin-induced osteoporosis
Dilantin-induced osteoporosis
Steroid-induced osteoporosis
What are the radiographic hallmarks of generalized osteoporosis?
Increased radiolucency (osteopenia)
Cortical thinning
Altered trabeculae patterns