Basic Science OITE HY Flashcards
(132 cards)
1
Q
Tensile Strength Ranking
A
max stress to failure is tensile strength
Co-C > Ti >Steel>Cortical Bone
2
Q
RSD of the knee
A
usually see patellar osteopenia, but most diagnostic test is relief from sympathetic block
3
Q
haversion canals
A
are in the center of an osteon in compact bone - contain vessels and nerves
4
Q
mannerfelt syndrome
A
rupture of FPL in Carpal Tunnel
5
Q
typ 1 vit D dependent labs
A
auto recessive - low Ca, low Phos, high ALP, high PTH, LOW 1,25 Vit D
6
Q
verification bias
A
if diagnostic test resuls impact wheather patientss are assigned treatment group
7
Q
what cell expresses RANK receptor
A
osteoclasts -
8
Q
most common site of frx in growth plate
A
prov calcification (part of zone of hypertrophy)
9
Q
BMP 3
A
antagonizes BMP 2, and is most common in DBX, increases the level of chondrogenic markers like Type 2 collagen and aggrecan
10
Q
MIS plating is better for which blood flow
A
both periosteeal and intramedullary
11
Q
typ2 vit D pathology
A
BADintracellular receptor for 1,25 vit D - tx with HIGH DOSE vit D and Ca; also has alpoecia and does NOT repsond to calcitriol
12
Q
SACH heel
A
solid fused ankle with wood heel and cushion around it
13
Q
what is responsible for TENSILE strength of bone
A
type 1 collagen
14
Q
locked plates and strain
A
less than conventional plating
15
Q
what secretes OPG
A
osteoBLASTS
16
Q
type 1 error
A
findingin an association that does NOT exist
17
Q
lovenox is
A
factor 2A and Xa inhibitor
18
Q
what is anakinra
A
IL-1a antagonist for RhA (2nd line) -
19
Q
most common cause of midstem failure in modular hips
A
FRETTING corrosion - also seen at head nekc junction
20
Q
what cell expresses RANK-L
A
OsteoBLASTS
21
Q
Myxoid liposarc gene and translocation
A
t12:16; TLS CHOP
22
Q
Rheumatoid immunology
A
Rh Factor is an IgM that attacks Fc part of IgG
23
Q
ideal vs total body weight for pain meds
A
use IDEAL weight for lipophillic pain meds
24
Q
fretting corrosion
A
resulting from contact sites b/w metals under load
25
effect of adding amino acids in rats w/ femur fracture
incr - serum albumin, body mass, quad total protein and frx callus mineralization; DECREASED effect of IGF 1,2 myosin, actin, VEGF mRNA were all decreased - key pt add 20%protein diet
26
OA changes
INCREASED: water, chondroitin sulfate, proteoglycan synthesis/degradation; DECREASED collagen content, proteoglycan content, keratin sulfate, modulus of elasticity
27
factor 5 function
normally is used to help Xa activate thrombin - which creates fibrin from fibrinogen - leading to CLOT; in Factor 5 Leidin - its not turned off by protein C so lots of thrombin gets made - lots of clots
28
long bone blood supply
inner 2/3 - Endosteeal; outer 1/3 - periosteeal
29
Ribosome antibiotic at 50subunit
chloramphenical, erythromycin (macrolides), clindamycin, and linezolid
30
mxn of axion heparin
blocks conversion of prothrombin to thrombin
31
Stats: Effect Size definition
magnitude of the difference in the means of the control and experimental groups in a study with respect to the pooled standard deviation. Effect sizes are normally used for continuous variables in contrast to relative risk reduction which is used for dichotomous variables.
32
Vit D regulates itself via
decreasing PTH release and 1-OH enzyme production
33
cement lines mark
the boundary of osteons
34
type 1 vit D pathology
cant convert to active 1,25 vit D (gene 12q14) - tx ith physiologic dose (1-2mcg) of vit D; responds to calcitriol and has NO alopecia
35
youngs modulus high to low
Ceramic > Alloy > Stainless Steel > Ti > Cortical Bone > Matrix Polymers > PMMA > Polyethylene > Cancellous Bone > Tedon/Lig >Cartialge
36
osteopetrosis
defect in CLCN 7 gene - abnormal osteoclasts
37
CRPS I vs II
II has a nerve lesion
38
Nutritional Rickets(Low D)
Low Ca, Phos, Vit D
High ALP,PTH
39
which factors assis osteoClast attachement to bone
vitronectin and integrin av
40
serum values in Vit D resistent Rickets (hypophosphatemic)
normal Ca, PTH and Vit D
LOW Phos, HIGH ALP
41
hookes law
stress is proportional to the strain in ELASTIC ZONE ONLY
42
cell cycle pahses
Initial growth (G1) > DNA synthesis (s) $n at the end > Gap 2 (G2) also 4N --> then M phase
43
mech of axn Rituximab
targets CD 20 - found on B-cells;
44
chi -sq vs fisher exact
chi-sq is for comparing proportions; Fishcer is for < 5 events in each group or sum < 50
45
high turnover renal osteodystrophy
leads to persistent elevated PTh even after renal disease is fixed
46
lab values in hypophos rickets (Xlinked)
low phos, high ALP and high PTH - caused by inability for kidneys to re-absorb phosphate back into body
47
what has greatest effect on ex-fix stiffnss
PIN DIAMETER
48
growth plate nutrient supply
perichondral Aa, and secondary via epiphyseal aa
49
recall bias
how pts remember things based on adverse experience
50
cannaliculi
are a system of canals within the lacunar system whereby osteocytes communicate with each other
51
Osteocalcin
most abudant NON_collangen protein in bone; promotes minneralizatin
52
Rhabdomyosarc gene, translocation
t2:13; Pax3-FKHR
53
sclerostin and Wnt
inhibits Wnt pathway which is normally used to promote osteoblasts
54
strain
change in length/original length
55
lab values in NUTRITIONAL rickets
NORMAL PTH, low phos, high alp, low/normal Ca
56
what is delayed type Hypersensitivity (type 4)
cell mediated - NOT ANTIBODIES
57
Chondrosarc gene and translocation
t9:22; fusion protein EWS-CHN
58
type 1 vit D
auto recessive
59
cancer markers Ovarian, Pancreatic, Breast, and Colorectal
CA-125 (ovarian); CA19-9 (pancreatic); CA15-3 (Breast); CEA - Colorectal
60
how heparin works
Antithrombin III (ATIII) is a potent inhibitor of the coagulation cascade. It is a nonvitamin K-dependent protease that inhibits coagulation by lysing thrombin and factor Xa. Antithrombin III activity is markedly potentiated by heparin, resulting in anticoagulation
61
OsteoNECTIN role
regulated Ca and mineral in matrix
62
toughness definition
amount of energy per volume a material can absorb before failure (fracture) - area under stress/strain cover - joules/m^3
63
Volkman Cannals are
within osteons and connect haversian canals to each other
64
groove of ranvier does
supplies chondrocytes at periphery for APPOSITIONAL growth
65
who to avoid giving Forteo
pagets, high ALP, open physis, or previous rad tx to axial skeleton
66
infliximab is
TNF alpha inhibitor
67
protamine is the antidote to what med
lovenox (LMWH)
68
components of cobalt-chrome
Chromium allows for corrosion resistance, and increases hardness
strength is increased by adding molybdenum
69
creep definition
constant load - deformation over time
70
plyometric contraction
when muscle rapidly lengthens just prior to contracting (repetitive box jumping)
71
crevice corrosion
resulting from different O2 tension
72
mech of axn-quinolones
inhibit DNA gyrase
73
pitting corrosion
resulting from localized pits on med surface
74
Ribosome Antibiotics at 30 subunit
Aminoglycoside and tetracyclin
75
bending rigidity of solid cylinder
radius to the 4th
76
ligament to bone insertion order
lig ->fibrocartilag -> mineralized fc-> bone
77
why does doxy help RhA pts
inhibits the collagenase which breaks down tissue in RhA
78
how to ginkgo and ginseng affect blood
inhibit platelet function
79
mazabraud syndrome
Poly-ostotic fibrsous dysplasia w. intramuscular myxoma a/w GNAS1 gene
80
formula for postiive LR
[TP/(TP+FN)]/FP Rate
81
effect of bisphos on OsteoP
65% reduction in new vt frx at 1 y, 40% at 3y, overal 39% drop in risk of NON_vt frx
82
steel vs co-chrome
steel is MORE susceptible to galvanic and crevice corrosion
83
biggest advatange of bicortical locking
greater torsional strenght
84
CaPhos vs CaSO4
Sulfate absorbs faster and is similary to cancellous bone; phos is x4 stronger takes 1 year to resorb
85
how does Forteo work
reproduces PTH effect by activating adenyl cyclase
86
Define Hypophosphatasia
low ALP due to error in production of tissue non-specific isoenxyme of ALP 9TNSALP) - high urine phosphoethanolamine is DIAGNOSTIC
87
aging cartilage
increases in Keratin Sulfate, modulus of elasticity, chondrocycte size, decreased water, proteoglycans, chondroitin sulfate, chondrocyte number
88
how does methotrexate work
blocks DHFR - dihydrofolate reductase
89
fxn of cathepsin K
secreted by osteoclasts at ruffled border for bone resorption
90
Stress defiinition
force over area
91
detection bias
when you look more carefully at one group than another
92
Ca requirements by age
1-3y: 500mg/d
4-8y: 800mg/d
9-18y: 1000-1500mg/d
>50y - 1200 to 1500mg/d
lactating women - 2000mg/d
93
type 2 vit D rickets labs
auto reccesive; low ca, low phos, high ALP, high PTH, HIGH 1,25 vit D
94
stat power def
1 - false negative
95
capacative coupling
using AC current to open Calmodulin channels and upregulate healing factors
96
xarelto (rivaroxaban) blocks
factor Xa directly
97
Clear cell sarc gene and translocation
t12:22; Fusion EWS-ATF1
98
UMN signs
mild weakness, spasticity, abnormally fast reflexes
99
incorporation bias
when someone stidies a diagnostic test that includes features of the target outcome
100
Bisphosphonate types
Non-Nitrogen containing - work via ATP analogue
Nitrogen Containin use farnesyl tranferase (stronger)
101
gene in FOP (fibrodysplasia ossificas progressivea)
stone man syndrome - BMP 4 is upreg - lots of HO forms
102
renal disease rickets labs
high phos, low ca, high ALP, high PTH
103
Nitrogen containing bisphhos mech of axn
(alendronate/Fosamax, pamidronate/Aredia, risedronate/Actonel) prevent protein prenylation by inhibiting farnesyl diphosphate synthase
104
what is thromboplastic
aka Tissue Factor TF - extrinsic coag pathway - activates factors 7 --> 10 --> prothrombin to thrombin = clot.
105
osteogenic BMP
2,4,6,7,9
106
SOX-9 role
chondrocyte differentiation pathway
107
LMN signs
progressive weakness, wasting, loss of reflexes and tone
108
LMWH mechanism of action
blocks factor Xa
109
when to use Wilcox Rank Sum
comparing two means from samples that are NOT normally distributed or small size
110
def of specificity
probability of negative test in pts who do NOT have the disease, TN/(FP+TN)
111
how does TXA work
compettiively binds to lysine residue to prevent activation of plasminogen
112
m-c complication of interscalene block
sensory neuropathy for 6 monts; followed by CRPS
113
rifampin works by
lipophilic and crosses cell membrane - works on RNA polymeraase
114
Gene and translocation in Ewings
t11:22; EWS-FL1 fusio protein
115
scurvy affects
collagen formation - seen in primary spongiosa of metaphysis
116
sensitivity defiinition
probability the test is positive IN PATIENTS WITH THE DISEASE
TP / (TP+FN)
117
Olliers Diseasee
multiple enchondromas due to Indian hedgehod malfxn in PTH pathway
118
bisphos in spine surg
decreased fusion rate
119
what Is responsible for compressive strenght of bone
proteoglycans and hydroxyappateitite are responsible for compressive strength of bone
120
osteopontin
cell binding protein
121
osteoCLAST precursor cell
monocyte origin from hematopoeitic cells
122
Synovial sarcoma gene and translocation
X:18; SYT-SSX1,2 o4 fusion protein
123
coumadin
prevents formation of factors 2, 7,9,10
124
orientation of chondrocyte and collagenin superficial zone of cartilage
flat cells parrallell to tidemark, fibers also parallel
125
PTH pathway
PTH responds to hypoCa and HyperMag - influences Kidneys to make more vit D, and gut to absorb more Ca, and bone to release more Ca and Phos
126
COX 2 roles
prostaglandin endoperoxide synthase 2; helps mesenchymal cells turn to OsteoBLASTS
127
working distance most affects
axial stiffness and torsional rigidity
128
what area do gigantism and achondroplasia affect
PROLIFerative zone
129
type 2 or beta error
falsely concludes no association when there infact IS one - false negative
130
rituximab is
cd20 blocker
131
benefits of giving EPO
lower transfusion rate, no difference in bleeding times wound complciations, or bone healing
132
hyper PTH labs
high pth, low phos, high alp, HIGH Ca
