Calcium and Bone Disorders Flashcards
what is osteoporosis
progressive skeletal disease characterised by low bone mass and deterioration of bone tissue
what causes osteoporosis to occur
increased bone turnover with increased osteoclast activity/increased bone resorption
list the risk factors for developing osteoporosis
age family history low BMI rheumatoid arthritis liver or renal failure early menopause steroid use coeliac disease
does osteoporosis present with symptoms
typically asymptomatic unless have pathological fracture
where are the common site of fractures seen in osteoporosis
colles
hip
vertebral wedge
what is the best investigation for diagnosing osteoporosis
dexa bone scan
how is a dexa bone scan interpreted
T score shows the number of standard deviations away from a young persons bone density
- 1 to -2.5 is osteopenia
- 2.5 or more is osteoporosis
outline the lifestyle management for osteoporosis
smoking cessation
alcohol reduction
resistance training
calcium supplements
what classes of drugs are used to treat osteoporosis
bisphosphonates
strontium ranelate
teriparatide - s/c injection only indicated if patient doesnt respond to other therapies
list examples of bisphosphonates
alendronate
risedronate
how do bisphosphonates work
kill off osteoclasts which reduces bone reasorption
one tablet taken once a week
what are the side effects of bisphosphonates
photosensitivity
GI upset
osteonecrosis of the jaw
what is Pagets disease of the bone
metabolic disease causing increased bone turnover, osteoblast and osteoclast activity increased and bone is deposited in a disorganised manner
how does Pagets disease present
deep bone pain that is worse at night and weight bearing
pathological fracture - commonly tibia, femur, skull and pelvis
state the complications of Pagets disease
pathological fractures
hypercalcaemia
nerve compression
describe alkaline phos, calcium and phosphate levels in Pagets disease
raised alk phos
normal calcium and phosphate
other than bloods tests, what investigations are done for Pagets disease
x-ray
early disease shows lytic lesions
late disese shows cortical thickening and deformity
how is Pagets disease managed
analgesia
bisphosphonates
describe the pathophysiology of osteomalacia and rickets
normal amount of bone but the mineral content of the bone is low
what is the difference between rickets and osteomalacia
rickets occurs during active periods of bone growth before growth plates have fused
osteomalacia occurs once the epiphyseal growth plates have fused
what causes osteomalacia and rickets
vitamin D deficiency
renal bone disease in context of CKD
cirrhosis - vitamin D cannot be activated
anti-convulsants
how does Rickets present
growth retardation
bow legged/knock knees
hypotonia
apathy
how does osteomalacia present
bone pain
fractures - neck of femur
proximal myopathy
waddling gait
outline the investigations done for osteomalacia and rickets
bloods showing hypocalcaemia
x-ray showing reduced cortical bone and scleritic lines
how is osteomalacia and rickets managed
calcium and vitamin D supplements
if renal disease - restrict fluids, phosphate binders
what causes primary hyperparathyroidism and how does it present
usually parathyroid adenoma or hyperplasia of all 4 glands
presents with hypertension, increased bone resorption and hypercalcaemia
what are the main symptoms of hypercalcaemia
fatigue thirst renal stones abdo pain depression
state the blood test findings for primary hyperparathyroidism
PTH and calcium high
phosphate low
what is the best investigation to diagnose hyperparathyroidism
sesatimbi scan to visualise the glands
how is primary hyperparathyroidism managed
watchful waiting
removal or adenoma or glands
what is the difference between secondary and tertiary hyperparathyroidism
secondary - physiological response in response to hypocalcaemia
tertiary - hyperplastic change due to prolonged hypercalcaemia, not a normal response
outline the biochemical profile of secondary and tertiary hyperparathyroidism
secondary - low calcium, raised phosphate and PTH
tertiary - raised calcium and PTH, low phosphate
how is secondary/tertiary hyperparathyroidism managed
treat underling cause with Vit D supplements
diet restriction if renal disease
what is hypoparathyroidism
low PTH hormone due to gland failure
what causes hypoparathyroidism
decreased Mg
Di George syndrome
haemochromatosis/Wilsons disease
thyroid surgery
how does hypoparathyroidism present (symptoms of hypocalcaemia)
numbness muscle cramps spasms wheeze anxiety
what is the biochemical profile of hypoparathyroidism
low calcium
low PTH
high phosphate
