Pathoma - Skeletal Muscle

Question 1

What is impaired in achondroplasia?

Answer 1

cartilage proliferation in growth plate

Question 2

Mutation in achondroplasia?

Answer 2

FGFR3

Question 3

Achondroplasia: Clinical presentation

Answer 3

short extremities with normal head/chest size

Question 4

Osteogenesis imperfecta:
Defect?
Leads to?

Answer 4

collagen I synthesis

weak bone

Question 5

Osteogenesis imperfecta: Clinical presentation

Answer 5

multiple fractures
blue sclera
hearing loss

Question 6

Osteopetrosis:

Mutation and effect

Answer 6

carbonic anhydrase II mutation

poor osteoclast function->can’t resorb bone

Question 7

Osteopetrosis:

Clinical presentation

Answer 7

FAVHHR:
Fractures (thick but abnormal bone)
Anemia/thrombocytopenia/leukopenia (thickening causes myelophthisic process)
Vision/Hearing impairments (CN compression)
Hydrocephalus (FM thickening)
Renal tubular acidosis

Question 8

Osteopetrosis:

Treatment

Answer 8

marrow transplant

Question 9

Rickets/Osteomalacia:

Cause

Answer 9

decreased Vitamin D

Question 10

Rickets/Osteomalacia:

Deficiency leads to:

Answer 10

defective mineralization of osteoid

Question 11

Rickets:

Population

Answer 11

children

Question 12

Rickets:

Clinical presentation

Answer 12

Pidgeon breast deformity
Frontal bossing
Rachitic rosary
Bowed legs

Question 13

What is a rachitic rosary?

Answer 13

Beads form along costochondral margins of ribs

Question 14

Osteomalcia:

Clinical presentation

Answer 14

weak bones/fracture risk

Question 15

Rickets/Osteomalacia:

Lab values

Answer 15

serum Ca2+ and phosphate decrease

PTH and alkaline phosphatase increase

Question 16

Osteoporosis:

Cause

Answer 16

loss of trabecular bone mass-> porous bone

Question 17

Osteoporosis:

Lose bone mass continuously after age 30 due to what factors?

Answer 17

Diet
Exercise
VitD receptors
Estrogen protective (premenopausal)

Question 18

Osteoporosis:

Most common forms

Answer 18

postmenopausal and senile

Question 19

Osteoporosis:

Clinical presentation

Answer 19

bone pain and fractures in weight-bearing areas

Question 20

Osteoporosis:

Diagnosis

Answer 20

DEXA scan

Question 21

Osteoporosis:

Lab values

Answer 21

all normal!

Question 22

Osteoporosis:

Prevention

Answer 22

exercise, Vit D, calcium

Question 23

Osteoporosis:

Common fracture sites

Answer 23

vertebral, femoral neck, distal radius (Colles’)

Question 24

Osteoporosis:

Treatment

Answer 24

estrogen (SERMs-Raloxifene), calcitonin, bisphosphonates (severe)

Question 25

Paget’s Disease:

Cause

Answer 25

imbalance in osteoblast/osteoclast function

etiology unknown

Question 26

Paget’s Disease:

Clinical presentation

Answer 26

thick, sclerotic bone (fractures easily) localized to 1+ bones
bone pain
increased hat size
hearing loss
"mosaic" pattern of lamellar bone
late adulthood onset

Question 27

Paget’s Disease:

Lab values

Answer 27

increased alkaline phosphatase

Question 28

Paget’s Disease:

Potential complications

Answer 28

osteosarcoma

high output cardiac failure

Question 29

Paget’s Disease:

Treatment

Answer 29

calcitonin, bisphosphonates

Question 30

Osteomyelitis:

cause and group affected

Answer 30

infection of bone/marrow space

usually in children

Question 31

Osteomelitis:

Location

Answer 31

metaphysis in chilren

epiphysis in adults

Question 32

Most common osteomyelitis infections (6)

Answer 32

1. S. aureus
2. N. gonorrheae (sexually active YAs)
3. Salmonella (sickle cell)
4. Pseudomonas (IV drug users, diabetes)
5. Pasturella (dog/cat bite)
6. TB (Pott’s Dz-lumbar vetebrae)

Question 33

Osteomyelitis:

Clinical presentation

Answer 33

pain w/ fever

leukocytosis

Question 34

Osteomyelitis on x-ray:

Answer 34

lytic focus (liquefactive necrosis) surrounded by sclerosis

Question 35

Avascular aseptic necrosis- causes

Answer 35

fracture/trauma
steroids
sickle cell

Question 36

Avascular aseptic necrosis: complications

Answer 36

osteoarthritis

fracture