Basic Science

Question 1

Which components of bone are most responsible for its compressive strength?

Answer 1

proteoglycans and calcium hydroxyapatite

Question 2

Which cytokine has been shown to promote scar tissue formation in lacerated skeletal muscle?

Answer 2

TGF-Beta

Question 3

Which class of medication has been shown to improve muscle regeneration and decrease fibrosis in normal skeletal muscle?

Answer 3

Angiotension II receptor blockers

Question 4

The sclerotome of the somites develops into what mature anatomical structure?

Answer 4

axial skeleton

Question 5

The neural crest develops into what mature anatomical structure?

Answer 5

peripheral nervous system

Question 6

The lateral plate mesoderm develops into what mature anatomical structure?

Answer 6

dermis

Question 7

The dorsal myotome develops into what mature anatomical structure?

Answer 7

dorsal muscles

Question 8

What is the most common radiographic finding in reflex sympathetic dystrophy (RSD) or complex regional pain syndrome of the knee?

Answer 8

patellar osteopenia

Question 9

What is the effect of anabolic steroids on LDL and HDL?

Answer 9

Increases LDL and decreases HDL

Question 10

What is the most common cause of Charcot arthropathy of the shoulder?

Answer 10

syringomyelia

Question 11

What are the 7 diagnostic criteria used to diagnose Neurofibromatosis-Type 1?

Answer 11

1) Six or more café-au-lait macules measuring at least 0.5 cm in diameter (before puberty) or at least 1.5 cm in diameter (after puberty).
2) Two or more neurofibromas of any type OR one plexiform neurofibroma.
3) Freckling in the axillary or inguinal regions (skinfolds).
4) Optic pathway glioma.
5) Two or more Lisch nodules (iris hamartomas).
6) Dysplasia of the sphenoid bone, or dysplasia or thinning of the cortex of the long bones (e.g., tibia).
7) First-degree relative with NF.

Question 12

What is the amount of energy per volume a material can absorb before failure (fracture)?

Answer 12

Toughness

Question 13

What is the function of the core binding factor alpha-1 (Cbfa1/Runx2)?

Answer 13

osteoblastic differentiation

Question 14

What is the mechanism of action for non-nitrogen containing bisphosphonates to induce osteoclast apoptosis?

Answer 14

Creating toxic analog of adenosine triphosphate that targets mitochondria

Question 15

What is the function of cathepsin K?

Answer 15

bone resorption

Question 16

What region of the physis does collagen type X play a prominent role?

Answer 16

zone of hypertrophy

Question 17

What is the range of pore size of cementless porous implants to allow for optimal bony ingrowth?

Answer 17

50 to 400 microns

Question 18

What is the inheritance pattern of Neurofibromatosis-Type 1?

Answer 18

Autosomal dominant

Question 19

What is the most prevalent noncollagenous protein in bone?

Answer 19

osteocalcin