Bone Diseases Flashcards
what is bone made of
calcium, phosphate, vitamin D
how is calcium lost
through gut and urine
why is it important that calcium is maintained at a precise level
it is involved in nerve and muscle function
how is calcium location controlled
through bone and ECF working together with parathyroid hormone
what are the functions of parathyroid hormone
maintains serum calcium level
increases calcium release from bone
reduces renal calcium excretion
what is primary hyperparathyroidism caused by
gland dysfunction by a tumour
what does hyperparathyroidism result in with regards to bone
increased bone reabsorption
how do we get vitamin D
produced by sunlight/absorbed from diet
in what ways can there be issues with vitamin D absorption
low sunlight exposure, poor GI absorption, drug interactions (antiepileptics)
what is osteomalacia
poorly mineralised osteoid matrix but bone formed normal (bone made softer)
what is osteoporosis
loss of mineral and matrix so reduced bone mass
what is osteomalacia called if it is formed during bone formation
rickets
why does osteomalacia occur
calcium deficiency
what are the effects on the bones with osteomalacia
bones bend under pressure so bow legs
bones ache to touch
vertebral compression in adults
what are the hypocalcaemia effects in osteomalacia
muscle weakness, troussea and chvostek signs positive, carpal muscle spasm, facial twitching from VII tapping
what do serum calcium phosphate and alkaline phosphatase measure
bone turnover
what is the management of osteomalacia
correcting the cause - malnutrition, sunlight exposure, dietary vitamin D
what is osteoporosis related to
age
what are the risk factors for osteoporosis
age, female, endocrine, genetic, patient factors, medical drugs
what are the patient factors for osteoporosis
inactivity, smoking, excess alcohol, poor calcium
what drugs are risks for osteoporosis
steroids, antiepileptics
what are the effects of osteoporosis
increased bone fracture, height loss and kyphosis, nerve root compression (back pain), increased hip fracture
what is kyphosis
bending forward of the spine
how do you minimise osteoporosis risk
build maximal peak bone mass early in life (exercise and high dietary calcium)
reduce rate or bone mass loss (HRT)
reduce drug related effects (use of bisphosphonates)
what do bisphosphonates do
poison osteoclasts and reduce their number
what are the 2 main types of bisphosphonates
non-nitrogenous and nitrogenous
what are the 3 most commonly found bisphosphonates
alendronate, ibandronate, zoledronate
what is the effect of bisphosphonates on osteoporosis
reduce vertebral fracture risk and other fractures
