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Flashcards in Primary Bone Tumors Deck (58):
1

What are the s/sx of hyperparathyroidism?

-Bones
-Stones
-Abdominal Groans
-Psychiatric overtones

2

What is the effect of PTH on ca resorption in the renal tubules?

Increases Ca resorption, and increases phosphate secretion

3

What is the effect of PTH on Vit D?

Increased synthesis of active form

4

What happens to Serum Ca and phosphate levels with PTH excess?

Increased

5

What is the most common cause of excess PTH?

Primary hyperparathyroidism

6

What is the tunneling reabsorption seen in Hyper PTH?

Lines on x-ray r/t osteoclast resorption 2/2 PTH

7

What are the brown tumors seen in hyperparathyroidism?

Collection of fibrous tissue, giant cells, and hemosiderin in bones that appear as areas of hypo-lucency on x-ray

8

What is renal osteodystrophy?

Chronic renal failure causes decrease in 1,24 (OH) D3 deficiency and associated secondary increase in PTH

9

What causes the osteomalacia with dialysis and renal osteodystrophy?

Metabolic acidosis, and increased PTH

10

What are the complications from renal osteodystrophy?

Osteitis fibrosa cystica
Osteomalacia

11

what is the pathophysiology behind Paget's disease of the bone?

1. Aggressive osteoclast-mediated bone resorption and
2. Imperfect osteoblast mediated bone repair

12

What is the progression of the pathophysiology of paget's disease of the bone?

First aggressive osteoclast resorption is more prominent, then imperfect osteoblast rapri becomes the larger factor

13

What is the supposed infectious etiology of Paget's disease?

Paramyxovirus increases expression of RANK receptor

14

What are the three major stages of Paget's disease of the bone?

1. Osteolysis
2. Osteoblastic
3. Osteosclerosis

15

Pt complaining of hat size changes = ?

Paget's disease of the bone

16

What are the histological findings of Paget's disease of the bone?

-Sclerosis of the bone with wide trabeculae
-Large amounts of osteoid

17

What happens to the osteoclasts with Paget's disease of the bone?

Increased size

18

What is the definition of scurvy?

Defective osteoid synthesis and collagen support of the blood vessels

19

What are the characteristic hair findings of scurvy?

Corkscrew hairs and petechiae

20

Where does hydroxylation of proline take place within a cell?

rER

21

What are some major complications of scurvy?

Subperiosteal hemorrhages

22

What, generally, is avascular necrosis?

Infarction of bone and marrow 2/2 ischemia

23

What are the common mechanisms that lead to avascular necrosis? (4)

-Fracture (mechanical vascular interruption)
-Corticosteroids
-Idiopathic
-Sickle cell disease

24

What are the gross characteristics of AVN?

Wedge shaped infarct in the bone, with separation of the subchondral area from the periosteum

25

Why is the femoral head particularly susceptible to avascular necrosis?

Hip fracture can shear off blood supply

26

What is the blood vessel that supplies the head of the femur?

Branch of the obturator artery

27

What are the two blood vessels that supply the neck of the femoral head?

Medial and lateral circumflex arteries

28

What is the first thing to happen when a bone is fractured?

Organization of a hematoma into a procallus

29

What happens with a fractures after a procallus has formed?

Conversion of the procallus to fibrocartilaginous callus caused by deposition of woven bone

30

What happens with a fracture after a fibrocartilaginous callus has formed

Replacement of the mesenchymal cells by osseous callus, with bone remodeling along stress lines

31

What is the order of calluses that occurs with fractures? (3)

Procallus
Fibrocartilaginous callus
Osseous callus

32

How much more common are fractures relative to primary bone tumors?

3000-4000x

33

What are greenstick fractures?

Incomplete fractures with closed skin, with bowing on the opposite side

34

What are stress fractures?

Fractures that develop slowly over time following a new repetitive stress

35

What are pathological fractures?

Diseased bone--non-traumatic

36

What is a compound fracture?

fracture where a part of the bone breaks through the skin

37

What is the enzyme that is defective with Gaucher's disease?

Defect in glucocerebrosidase

38

What is happening in the 0-3 day timeframe of fracture healing?

Hemorrhage, inflammatory infiltrate, and granulation tissue

39

What is happening in the 3-7 day timeframe in fracture healing?

Chronic inflammation with granulation tissue and osteoclastic activity

40

What is happening in the 7-35 day time frame of fracture healing?

Progressive increase in cartilage woven bone and cartilage formation

41

What is happening in the 35+ day time frame of fracture healing?

Secondary callus, and replacement of woven bone by lamellar bone

42

What are the five major impediments to fracture healing?

-infection
-non-union
-Poor circulation
-Drugs

43

What is osteomyelitis?

Inflammation of the bone and marrow caused by infection

44

What are the bacteria that commonly cause osteomyelitis in sickle cell patients?

Salmonella

45

What are the three major routes of spread for osteomyelitis?

-Hematogenous
-Direct extension
-Open fracture or surgery

46

What is the most common bacterial cause of osteomyelitis in general?

Staph aureus

47

What usually follows initial osteonecrosis with osteomyelitis?

Subperiosteal pyogenic abscesses

48

What is the sequestrum with chronic osteomyelitis?

Residual necrotic bone

49

What is the involucrum with chronic osteomyelitis?

Rim of reactive bone around sequestrum

50

What is a brodie abscess?

Walled off abscess in bone by sclerotic bone

51

True or false: viable organisms may persist in brodie abscesses

True

52

What are some complications of chronic osteomyelitis?

Draining sinuses to the skin, which may serves as a nidus for sepsis or cancer

53

What cancer do patients with chronic osteomyelitis have an increased risk for?

Osteosarcoma

54

What usually causes tuberculosis osteomyelitis?

Hematogenous spread, but can be direct extension

55

What bones in particular are affected with tuberculous osteomyelitis?

Vertebrae and long bones

56

What is Pott's disease?

TB of the vertebral bodies, producing a gibbus deformity (loss of vertebral body encroaches on spinal cord)

57

Why is there a resurgence of tuberculous osteomyelitis in developed countries?

Immigration and immunosuppressed people

58

What is the general progression of tuberculous osteomyelitis?

Starts in the synovium, then progresses to the epiphysis and through the medullary cavity