Questions Flashcards
what zone does gigantism and achondroplasia affect? how about for fractures?
- zone of proliferation
- remember it goes reserve (gauchers)
- hypertrophy (fractures
bone is weakest with ___ forces and strongest against ___ forces
shear (NOT tension); compression
X-linked rickets:
- what is the Ca level?
- what is the phosphate level?
- what is the gene?
- it is the most common form of ___
- what is PTH?
- Normal
- Low
- PHEX
- hereditary rickets
- Normal; it would be high with nutritional rickets
how does induction coupling work? what is this seen with for treatment of nonunions?
-stimulates osteoblasts, increases expression of BMP-2, BMP-7, and tgf-beta
-bone stimulators
IT DOES NOT CHANGE OSTEOCLAST FUNCTION
What is the cell lineage for osteoblasts? osteoclasts?
- mensenchymal stem cells
- hematopoetic stem cells from macrophage lineage
what is the gene for x-linked rickets?
what is the gene for Osteogensis imperfecta?
- PHEX
- COLIA1, COLIA2
what are the functions of protein C/S?
they inhibit the coagulation cascade thus deficiencies in them would cause increased amounts of clotting; also remember that warfarin first inihibits them quicker than the coag factors thus you have a brief hypercoagable state when started it
what molecule is released during surgical dissection that increases coagulation?
thromboplastin which activates factor VII which activates factor X and then activates factor II (prothrombin to thrombin)
what is the mechanism of enoxaparin?
aka lmwh that activates antithrombin III and forms a complex that binds to Xa and prevents Xa from converting II to IIa (prothrombin to thrombin)
tell the activity of TA and Gastroc during toe off, swing and heel strike
- TA: dormant, concentric to clear the toes from the ground, eccentric to lower the foot
- GC: concentric during toe off, dormant during swing, and eccentric during flat foot as the bodyweight transfers
what diseases are included when testing blood for transfusions?
HIV 1 and 2, west nile, hep B and C, syphilis
what is the inheritance for becker’s and duchenne muscular dystrophy?
x-linked recessive
Anisotropic vs isotropic?
Mechanical properties change depending on the orientation of the stress vs those that don’t; examples of anisotropic are menisci, cartilage, cortical/cancellous bone and isotropic would be implants
- nitrogen containing bisphosphonate
2. non-nitrogen containing bisphosphonate
- inhibit GTPase formation which prevents GTP prenylation
2. cause apoptosis with ATP analogs
what is the function of denosumab?
human monoclonal antibody that binds to RANKL
use of topical vancomycin decreases ___ but increases ___
- SSIs
- gram negative infections as the positive goes down
BMP 2 is approved for ____ with fixation via ___ while BMP 7 is approved for ____
- open tibial shaft fixed with IMN within 14 days of initial injury
- long bone nonunions
what are the 3 principal layers of the growth plate? what does gigantism affect?
- reserve, proliferative, hypertrophic
- proliferative
what happens to the cartilage of a limb that is NWB and what happens to the contralateral limb during that time?
-thinning to NWB and no changes to contralateral side
what is the initial abnormality and phase with paget’s disease?
it starts with increased bone remodeling and turnover that is abnormal with increased osteoclast absorption; there is then a mixed phase followed by sclerotic phase where the osteoblast dominates
fibrin is an end product of the ___ ____ and is factor ____ formed from ____
- coagulation cascade
- IIa
- thrombin
Sclerostin and DKK-1 downregulate what pathway? what does this result in?
- wnt/beta-catenin via the LRP 5/6 receptor
- osteoblast formation
what is the most common pathogen with cat bites? dog bites?
- pasteurella multifoca
- pasteurella canis
what are the 3 stages of tendon healing?
what is the weakest?
- inflammatory, proliferative, and maturation
- inflammatory
Deep zone of cartilage has ____ fibers and ____ proteoglycans; superficial zone has ___ fibers and ___ proteoglycans
- perpendicular
- high
- parallel
- low (more water)
Osteocytes communicate in the lacunar network through ____; what is the in the haversian canals? what connects the canals?
- canaliculi
- blood vessels
- volkmann’s canals
what is the small part of the C-arm? what is the large part? which has more radiation exposure?
- source is the small side and the intensifier is the large side
- the source
what is the function of decorin?
-proteoglycan that helps regulate fibril size in collagen
what allows staph epidermidis to adhere to surfaces?
forms a biofilm/glycocalyx that lets it attach to the implants which helps it to resist phagocytosis
what type of collagen is primarily made during the inflammatory early healing phase? what about later?
- type III
- type I
BMP 2 is approved for ____ tibial shaft fractures while BMP 7 is approved for ___ tibial shaft fractures
- acute, open
- closed nonunion
what does viscoelastic mean?
stress-strain curve is time/rate dependent; example being ligaments
go through the 4 types of allergic hypersensitivities
search on orthobullets
Modulus of elasticity: what is this a measure? the higher the modulus the ___ a material is, list common implants relative to cortical bone
- stress/strain curve of a material reflects the stiffness
- stiffer
- cortical bone - titanium - stainless steel - cobalt chrome - ceramic