Developmental dz of bone

Question 1

Radiographs of a 32 wk still born fetus show minimal mineralization at the skull base. Long Bones show general demineralization. The provisional zones of calcification are preserved (ends of long bones are sharp). Ribs show beaded appearance secondary to multiple fractures. Dx?

Answer 1

OI

Question 2

Blue sclera seen in OI are due to?

Answer 2

The blue discoloration occurs when thinning of the sclera allows the underlying choroid to become visible

Question 3

Autosomal dominant condition with reduction of chondrocytes at growth plates. Dx?

Answer 3

Achondroplasia

Question 4

Pt. comes in because of fatigue and also complains of hearing loss. You discover he’s anemic, leukopenic, and has renal tubular acidosis. The xray shows long bones without medullary cavities and bulbous ends. How do you Tx him?

Answer 4

Bone marrow transplant b/c pt. has osteopetrosis. He had metabolic acidosis because of the carbonic anhydrase II deficiency.

Question 5

75 year old women comes in complaining of hip pain. Labs show normal serum Ca, phosphate, and alkaline phosphatase. A photomicrograph shows thin trabaculae. Xray confirms hip fracture. What’s her prognosis?

Answer 5

Hip fracture in osteoporosis is associated with high early mortality.

Question 6

A man with northern european descent comes in with lower back pain. You notice he has a hearing aid. Upon exam you see bowing of the legs and curvature of the spine. Dx?

Answer 6

Paget’s dz

Question 7

Kid comes in with a fracture and you notice bowing of the legs. Biopsy shows surfaces of bony trabeculae that are calcified and covered by a thicker than normal layer of osteoid. This pt’s condition is due to?

Answer 7

Low vit. D