Bones Flashcards
what is most common cause of hypercalcemia?
primary hyperparathyroidism
80% single parathyroid adenoma
usual presentation of hyperparathyroidism
asymptomatic hypercalcemia or renal stones
can have phosphate and bicarb wasting -> non anion gap meta acidosis
familial benign hypocalciuric hypercalcemia
autosomal dominant
loss-of-fnx mutation in CaSR
elevated PTH and magnesium Dx with low urinary Ca clearance
must be Tx medically
Tx of hypercalcemia
IV fluids loop diuretics IV bisphos calcitonin glucocorticoids cinacalcet hemodialysis
acquired hypoparathyroidism
thyroidectomy multiple parathyroidectomies removal of parathyroid adenoma (transient) neck radiation heavy metals (copper, Fe) granulomas sporadic immunity tumors infection riedels thyroiditis magnesium deficiency PGA type 1
PGA type 1
autoimmune polyendocrinopathy
presents in childhood with candidiasis, hypoparathyroid, addisons disease
may also have cataracts, uveitis, alopecia, vitiligo, or autoimmune thyroiditis
congenital hypoparathyroidism
abnormal CaSR
barakat or HDR syndrome
DiGeorge syndrome
Barakat/HDR syndrome
hypoparathyroidism Deafness Renal dysplasia autosomal dominant mutation of GATA3 hypocalcemia mental retardation and hypocalcemic tetany
DiGeorge syndrome
deletion of chrom 22 hypocalcemia with tetany facial anomalies tetrology of fallot thymic aplasia cleft palate
pesudohypoparathyroidism
end-organ resistance to PTH hypocalcemia hyperphosphatemia increased PTH normal PTHRs in bone therefore boney symptoms of hyperparathyroidism
pseudopseudohypoparathyroidism
phenotypic abnormalities w/o hypocalcemia
albright heredetary osteodystrophy
short stature, obese
bradydactyly, round faces
dermal ossifications mental retardation
pseudohypoparathyroidism
osteomalacia
soft bones
bones remodel, but do not mineralize dt vit D deficiency
pain, fractures
hypomagnesemia
cofactor for PTH secretion
common in chronic GI disease, nutritional deficiency, alcoholism, cis-platinum therapy
pagets disease
focal disorder of bone remodeling -> greatly accelerated rates of bone turn over
unknown etiology
pagets symptoms
often asymptomatic HA bone pain and deformity (enlarged head, bowed long bones) warmth of skin over bones high CO entrapment neuropathies (hearing loss) Kyphosis fracture with only slight trauma
complications of pagets
‘vascular steal’ from spinal cord -> paralysis
phases of pagets
osteolytic
mixed
osteoblastic
osteolytic
advanding wedge-shaped resorption at either end of long bones or circumscribed osteolytic lesion in skull
mixed phase
less bone remodeling, more sclerosis
enlarged bone, bowing, fractures
osteoblastic pahse
cotton wool appearance w/patchy increase in bone density
bone scan shows osteoblastic uptake
Tx of pagets
controversial if asymptomatic
bisphos (DOC)
Calcitonin
labs in pagets
elevated alk phos elevated C-telopeptide elevated urinary hydroxyproline elevated serum Ca vit D deficiency
gold standard to measure BMD
DEXA
T-score
standard deviation from mean BMD of young healthy population
used to Dx osteoporosis
Z-score
standard deviation of BMD age and sex matched group
osteopenia T score
-1 to -2.5
osteoporosis T score
<-2.5
established osteoporosis
T score <2/5 and fracture
Zoledronate
new bisphos
single injected dose/yr
osteoporosis values
Ca- affected phos-unaffected alk phos-variable PTH- unaffected decreased bone mass
osteopetrosis
Ca unaffected phos- unaffected alk phos unaffected PTH unaffected thick dense bones
osteomalacia and rickets
Ca decreased phosphate decreased alk phos variable PTH elevated soft bones
osteitis fibrosa cystica
ca elevated phos decreased alk phos elevated PTH elevated brown tumors
pagets
ca unaffected phos unaffected alk phos elevated PTH unaffected abnormal bone remodeling
