Mcw Path Block 6

Front 1

Inorganic elements in bone (2)

Back 1

Ca, PO4

Front 2

Organic elements of bone

Back 2

Type I collagen

Front 3

pluripotent stem cells, turn into osteoblasts

Back 3

osteoprogenitor cells

Front 4

synthesize proteins, initiate mineralization of bone

Back 4

osteoblasts

Front 5

cells within bone, communicate through canaliculi

Back 5

osteocytes

Front 6

resorb bone

Back 6

osteoclasts

Front 7

*unmineralized bone

Back 7

osteoid

Front 8

bone seen in fetal skeleton and at growth plates

Back 8

woven bone

Front 9

bone that replaces woven bone and is stronger. Bone is in orderly layers

Back 9

lamellar bone

Front 10

when does skeletal mass begin to decline?

Back 10

after 4th decade - amt of bone formed is less than amt of bone resorbed

Front 11

central part of bone

Back 11

diaphysis

Front 12

3 characteristics of diaphysis

Back 12

1. central part of bone
2. from primary ossification center
3. metaphysis is end of diaphysis

Front 13

end of diaphysis before epiphysis is called

Back 13

metaphysis

Front 14

epiphysis (2)

Back 14

1. end of long bones
2. from secondary ossification center

Front 15

physis (2)

Back 15

1. between diaphysis and epiphysis
2. responsible for growth until fusion

Front 16

4 major parts of a long bone

Back 16

diaphysis, metaphysis, epiphysis, physis

Front 17

4 types of fractures

Back 17

closed - overlying tissue intact
compound - communicates with the skin
comminuted - bone is splintered
pathologic - fracture in already diseased bone

Front 18

5 steps in fracture healing

Back 18

1. hematoma formation
2. procallus formation
3. soft callus
4. hard callus
5. remodeling

Front 19

procallus

Back 19

inflammation with granulation tissue, collagen forms between fractured ends

Front 20

soft callus

Back 20

osteoprogenitors deposit woven bone, may deposit cartilage.
Not weight bearing!

Front 21

hard callus

Back 21

mineralization through enchondral ossification

Front 22

false joint due to untreated fracture

Back 22

pseudoarthrosis

Front 23

2 causes of osteomyelitis

Back 23

1. hematogenous spread (MC. Long bones & vertibrae)
2. Direct spread or innoculation (surgery, open fracture)

Front 24

osteomyelitis in a neonate is usually found in the...

Back 24

metaphysis and/or epiphysis

Front 25

osteomyelitis in a child is usually found in the...

Back 25

metaphysis

Front 26

osteomyelitis in an adult is usually found in the...

Back 26

epiphysis & subchondral regions

Front 27

MC organism in osteomyelitis

Back 27

S aureus

Front 28

osteomyelitis due to EtOH or IV drug use

Back 28

Group G strep

Front 29

osteomyelitis in neonate (causative organisms) (2)

Back 29

Hib, Group B strep

Front 30

osteomyelitis due to heroin use

Back 30

p. aeruginosa

Front 31

osteomyelitis in sickle cell patient

Back 31

salmonella

Front 32

osteomyelitis in an immunocompromised patient

Back 32

All others + mycobacterium & fungal species

Front 33

osteomyelitis due to GU infection

Back 33

E. Coli,
Pseudomonas,
Klebsiella

Front 34

*necrotic piece of bone from ischemic injury

Back 34

sequestrum

Front 35

*reactive or woven bone around sequestrum

Back 35

involucrum

Front 36

soft tissue abscess from periosteum rupture

Back 36

draining sinus

Front 37

small abscess surrounded by reactive bone

Back 37

brodie abscess

Front 38

Radiology:
bone destruction surrounded by zone of sclerosis

Back 38

Dx: osteomyelitis

Front 39

5 factors in primary osteoporosis

Back 39

1. Vitamin D receptor polymorphisms—hereditary
2. Physical activity
3. Muscle strength
4. Diet
5. Hormonal state—loss of estrogen is bad

Front 40

primary vs secondary osteoporosis?

Back 40

Primary=loss of bone mass during agine
secondary=loss of bone mass due to something else (malabsorption, multiple myeloma, etc)

Front 41

4 possible causes of seconday osteoporosis

Back 41

1. Endocrine (hyperparathyroidism)
2. Multiple myeloma
3. Malabsorption
4. Corticosteroids

Front 42

what is the rule of 2's?

Back 42

the normal ranges of bone values all have "2" in them:
bone volume - >20%
osteoid surface - ~20%
osteoid vol - ~2%
mean trabecular width = 200um
osteoclasts - .2/mm2 bone
calcification rate = 1/2 um/day
mineralization lage time=20 days

Front 43

how Dx osteoporosis? (3)

Back 43

values outside of rule of 2's
DEXA scan
CT: lumbar spine

Front 44

Rickets vs Osteomalacia?
(who gets? what causes?)

Back 44

Rickets - children
osteomalacia - adults

due to lack of vitD or problem in metabolism

Front 45

deranged bone growth & skeletal deformity in child

Back 45

rickets

Front 46

adult with undermineralized bone & predesposed to fractures

Back 46

osteomalacia

Front 47

mosaic pattern of lamellar bone what resembles jigsaw puzzle produced by prominent cement lines

Back 47

paget's disease

Front 48

increased abnormal bone mass

Back 48

paget's disease

Front 49

paramyxovirus infection with IL-6 induction --> ???

Back 49

paget's disease

Front 50

bone has many resporption pits. osteoclasts are larger than normal & have >10-12 nuclei

Back 50

Lytic phase of paget's disease

Front 51

osteoclasts persist with prominent osteoblasts lining the bone surfaces. marrow is replaced by loose connective tissue

Back 51

mixed phase of paget's disease

Front 52

bone becomes its own caricature but is larger than normal and hase hoarsely thickened trabeculae

Back 52

osteosclerotic stage of paget's disease

Front 53

paget's disease usually effects what bones

Back 53

long bones of axial skeleton. especially femur

Front 54

pagets disease in bones other than pelvus, skull

Back 54

monostotic

Front 55

pagets disease in pelvis, skull

Back 55

polyostotic

Front 56

increased alkaline phosphatase and urinary hydroxyproline

Back 56

pagets disease!!!!

Front 57

*3 major complications of paget's disease

Back 57

1. compression of cranial or spinal nerve roots (ex: hearing loss)
2. high output cardiac failure due to increased blood flow (bone acts like A-V shunt)
3. **malignancy - usually osteosarcoma**

Front 58

cause of primary hyperparathyroidism?

Back 58

hyperplasia or tumor of parathyroid

Front 59

*cause of secondary hyperparathyroidism?

Back 59

prolonged hypocalcemia with increased PTH secretion

Front 60

anatomic changes of skeleton due to hyperparathyroidism

Back 60

osteitis fibrosa cystica (aka: von Recklinghausen disease of bone)

Front 61

*morphology of osteitis fibrosis cystica (due to hyperparathyroidism)

Back 61

1. Thinned cortices and loss of lamina dura around teeth
2. Cortical cutting cones—spearhead arrangement of osteoclasts
3. Railroad tracts (dissecting osteitis) in cancellous bone
4. Microfractures with hemorrhages are common
4a. Influx of macrophages with fibrosis (**brown tumor**)