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Flashcards in Bone disorders II Deck (19):

What do we see with rickets on X ray?

metaphyseal flaring with cup-shaped deformity


genetic causes of vitamin D deficiency

type I: 1 alpha hydroxylase deficiency
type II: vitamin D receptor deficiency


Most common cause of osteomalacia in adults

intestinal malabsorption


lab results in osteomalacia and rickets

decr. calcium, decr. phosphate, incr. alk phos, decre 25 oh vitamin D, incr PTH
phosphate is important- if it is high, think of renal osteodystrophy instead


Why should I think about bone in CKD?

much more likely to have fracture
stage 3 or higher need vit D supplementation


what is renal osteodystrophy

combo of hyperparathyroidism and osteomalacia
high phosphate low 1a hydroxyalse = low calcium
may be from aluminum toxicity


What are some manifestations of renal osteodytrophy

4 gland hyperplasia of parathyroid with chronic low calcium
skeletal resistance to PTH
may see amyloid formation in the skeleton and soft tissue/organs


Labs with renal osteodystrophy

low Ca
high PTH
high PO4
low GFR


treatment of renal osteodystrophy

manage mineral metabolism
treat w vitamin D
manage acidosis
if parathyroidism is severe, consider parathyroidectomy
treat fractures


What is osteopetrosis?

normal new bone formation but deficiency of bone and cartilage resorption
decr. or absent osteoclasts
large numbers of defective osteoclasts


phenotypes of osteopetrosis

adult form:
carbonic anhydrase II gene mutation


adult osteopetrosis. symptoms and inheritance

most common form, normal lifespan, mild anemia
autosomal dominant


congenital osteopetrosis

autosomal recessive
causes death in childhood
anemia, thrombocytopenia, hepatosplenomegaly, immune system compromise, cranial and optic palsies


carbonic anhydrase II gene mutation

associated with renal tubular acidosis, cerebral calcifications, and intellectual disability


treatment of osteopetrosis

IFN-gamma is FDA approved
maybe bone marrow transplant
some success with massive doses of 1,25 vitamin D


Paget's disease: epi, what is it

most common metabolic bone disease after osteoporosis
exaggerated, nonphysiologic bone remodeling
may be genetic and viral etiologies, though largely unknown


Paget's disease: phases

initially see an incr. number of large active osteoclasts: hot phase
then see disorganized new bone formation (incr. alk phos activity). mosaic pattern
final phase has decreased osteoblast AND osteoclast activity: cold phase.


Paget's disease: locations, X ray

pelvis, lumbar spine, skull
flame shaped long bones
initial radiolucency


Tx of paget's disease

most pts are asymptomatic
if there is pain or lots of breakdown produces, give bisphosphonates, NSAIDS, calcitonin
be careful with operations- they can have lots of bleeding because tissue is hilghy vascular
may develop rapidly fatal high grade osteosarcoma.