Shared Flashcard Set

Details

Body Synthetic - BioMechanics
knee, hip, and spinal implants
176
Biology
Undergraduate 2
07/09/2014

Additional Biology Flashcards

 


 

Cards

Term
proximal
Definition
towards the head
Term
distal
Definition
away from the head
Term
condyles
Definition
knobs/bulbs on the end of the bone. ex) femoral condyles
Term
tibial plateau
Definition
surface of tibia femoral condyles articulate with
Term
trabecular bone
Definition
spongy bone, near ends of bone, allows redirection of forces into bone shaft
Term
cortical bone
Definition
hard, sturdy, dense bone, in bone shaft, allows for support
Term
lateral
Definition
away from center line
Term
medial
Definition
towards center line
Term
epiphysis
Definition
end of the bone -
ends transfer load from different directions, then towards the middle.
more yield at the ends, can compress more before failure
Term
diaphysis
Definition
middle of the bone -
made of cortical/compact bone
Term
epiphysial growth plate
Definition
bone grows outward in from here - fuses after puberty
growth plate offers least resistance, common to fracture here
Term
three bones in knee
Definition
tibia, patella, femur
Term
three compartments of knee joint
Definition
medial femoral, lateral femoral, patellar
Term
two joints in knee
Definition
tibio femoral joint, patello femoral joint
Term
articulation
Definition
load bearing bone interaction
Term
meniscus, articular cartilage
Definition
lines the joints, limits friction and creates deeper sockets, cushions and stabilizes
lowers coefficient of friction to 0.001
energy expended creates motion instead of overcome friction
Term
patella location
Definition
embedded in patellar tendon
Term
dynamic stabilizer
Definition
muscles, tendons, structures that move and stabilize joint
Term
static stabilizers - knee
Definition
ligaments. ACL, PCL, LCL, MCL
(anterior, posterior, lateral, and medial cruciate ligaments)
Term
fibrocartilagenous joint sac
Definition
sac of fluid around knee joint filled with fluidand seals to lubricant joint
Term
synovial fluid
Definition
fluid that fills sacs around joints
Term
causes of an ACL tear
Definition
plant and turn injury, rupture of synovial sac
Term
arthroscopic debridement
Definition
shave rough cartilage off to create a smooth surface once more
Term
degrees of freedom
Definition
6 total - three axes, translation and rotation about each
Term
how many degrees of freedom does the knee have?
Definition
6 degrees of freedom. 3 active, 3 passive, and one mostly
Term
TKR
Definition
total knee replacement
Term
osteoarthitis
Definition
wear out of cartilage, rubbing of bone (non inflammatory)
Term
rheumatoid arthritis
Definition
autoimmune, inflammatory response against body's own cartilage
Term
two cause of osteoarthritis
Definition
idiopathic - onset by age
post traumatic - caused by injury
mechanical load misalignment
Term
symptoms of arthritis
Definition
bones start to rub
bony spur creation
ligaments weaken from lesser load (mechanical misalignment)
muscle atrophy from no use
Term
which is more common? hip or knee arthitis?
Definition
knee - 80% over 75 years old
Term
why is knee arthitis more common in women after 55?
Definition
menopause and hormonal changes
Term
risk factors of osteoarthritis
Definition
increasing age
obesity
gender - female
trauma
infection
repetitive occupational trauma
Term
genuvatus
Definition
bow legs
Term
crepitus
Definition
noise knee makes
Term
non pharmacological therapy (5)
Definition
patient education
use of assistive devices
weight loss
physical therapy
occupational therapy
Term
pharmacological therapy (4)
Definition
NSAIDS (non steroidal anti inflammatory drugs)
glucosamine sulfate
intra articular corticosteroids
intra articular hyaluronic acid
Term
disadvantages of steroid shots
Definition
affect how condocytes are produced (main building block of cartilage)
disrupts the capsule
Term
osteotomy
Definition
remove wedge from tibia to realign the mechanical loading of the joint (altered due to arthitis)
Term
conditions needed for osteotomy
Definition
60yo or younger, 90 degrees of motion before surgery
Term
partial knee replacement
Definition
unicompartental replacement (one condyle and part of the tibial plateau)
done with critical trauma - younger patient
Term
total knee replacement
Definition
replace both condyles and entire tibial plateau
Term
unconstrained knee implants (3)
Definition
cruciate retaining/sparing
cruciate subsituting (posterior stabilized - PS knee)
Mobile bearing prosthesis (rotating platform implant)
Term
constrained knee implant
Definition
hinged
Term
osteolysis
Definition
device pulling away/separating from the bone
Term
most popular knee implant
Definition
PS - posterior stabilized
Term
mobile bearing prosthesis - success or failure?
Definition
failure - allowed unnecessary movement - failure rate actually INCREASED
Term
constrained knee implant - when is it recommended?
Definition
when muscle strength is not there, compensates for lack of dynamic constraint
Term
lifespan of knee replacement
Definition
15 years
Term
materials for TKR
Definition
stainless steel
cobalt-chromium alloys
titanium alloys
tantalum (trabecular metal)
zirconium alloy
UHMWPE
Term
UHMWPE
Definition
ultra high molecular weight polyethylene
Term
metal on metal disadvantage
Definition
wear debris into bloodstream, not healthy
loosening, breakage, fracture, pain, stiffness, instability
Term
cemented vs uncemented TKR
Definition
Term
bone cement material
Definition
PMMA - polymethylmethacrylate
Term
cementless encourages what?
Definition
osteointegration
Term
downsides to cementless fixation
Definition
low bone density
longer healing time
not popular in practice
Term
differences between cement and cementless devices
Definition
cement smooth
cementless: textured, holes through femoral component
Term
hybrid fixation
Definition
femoral component fixated without cement
tibial and patellar components are inserted with cement
Term
downsides to cement fixation
Definition
if replacement surgery is needed, cement must be chiseled out
Term
most successful material combination?
Definition
metal on plastic
femoral component metal
tibial component plastic
Term
change in knee axis orientation is due to what?
Definition
difference in size of lateral and medial femoral condyles
Term
polycentric joint
Definition
axis changes as the joint rotates
Term
radius of curvature
Definition
radius of circle created by rotation path at any specific moment (will vary due to polycentricity)
Term
screw-home mechanism of the knee
Definition
last 20 degrees of extension, knee goes into external rotation and locks
geometric congruity in flexion, after first 15-20 degrees, knee unlocks
Term
TKR components
Definition
cobalt-chrome alloy femoral component
cobalt-chrome alloy/titanium tibial tray
UHMWPE tibial bearing component
UHMWPE patella component
Term
robotic knee surgery benefits
Definition
accuracy, personalized replacement designs, reduce risk of future complications
Term
Q-angle
Definition
angle between line of action of force (mechanical alignment of knee) and line from origin of quadriceps to tibial line
Term
women Q-angle
Definition
hips widen at puberty, larger Q-angle, more prone to injury
Term
coronal plane
Definition
separates anterior from posterior
Term
sagittal plane
Definition
separates left from right
Term
axial plane
Definition
separates top from bottom (proximal from distal?)
Term
labrum
Definition
cartilagenous extension from hip socket that stabilizes joint
Term
acetabulum
Definition
hip socket
Term
stabilizing ligament in hip
Definition
circular, round ligament
Term
reasons for hip replacement (5)
Definition
osteoarthritis
rheumatoid arthritis
traumatic arthritis (injury that damages cartilage)
hip fractures (results in degeneration)
avascular necrosis (head of femur loses blood supply and dies)
BONUS: idiopathic osteonecrosis - without known cause
Term
modular
Definition
multiple separable parts that allow for easier replacement
Term
cementless hip replacement
Definition
femoral component with hole in stem, beads on surface to mimic pores in bones,
Term
increased angle of torsion
Definition
pigeon toed
Term
decreased angle of torsion
Definition
duck foot
Term
normal angle of inclination for hip
Definition
125
Term
range of hip flexion/extension
Definition
140
Term
larger hip angle of inclination consequences
Definition
more force on head, longer limb
Term
smaller hip angle of inclination
Definition
more force on neck, shorter limb
Term
two lines that make up angle of inclination
Definition
femoral neck and femoral shaft - obtuse angle
Term
valgus
Definition
distal end of bone shifted laterally
Term
varus
Definition
distal end of bone shifted medially
Term
coxa valga
Definition
bow legged (in reference to hip joint)
Term
coxa vara
Definition
knocked knees (in reference to hip joint)
Term
genu valga
Definition
knocked knee (in reference to knee joint)
Term
genu vara
Definition
bow legged (in reference to knee joint)
Term
angle of torsion
Definition
angle between femoral neck line and axis of femoral condyles
(in reference to hip, distal end of femur is torqued)
Term
normal angle of torsion (#)
Definition
12-15 degrees
Term
hip replacement components
Definition
femoral stem (metal), separate head piece, acetabular cup/shell (metallic), inner liner (metal, ceramic, polyethylene)
Term
monobloc
Definition
inner liner of hip replacement
Term
monolithic
Definition
one piece
Term
large femoral head pros/cons
Definition
high stability/high wear
Term
small femoral head pros/cons
Definition
higher chance of dislocation/lower wear
Term
polyethylene on metal hip replacement
Definition
most common
greatest wear on all material combos
wear results in osteolysis
Term
ceramic on ceramic hip replacement
Definition
high density, high purity, small grain
little debris
excellent wear resistance
no toxic side effects
no evidence of osteolysis
expensive
squeaky hip
low fracture toughness
Term
ceramic on polyethylene hip replacement
Definition
.05 mm per year
new ceramics have low fracture rates
more expensive than metal on poly, less than ceramic on ceramic
Term
metal on metal hip replacement
Definition
allow for larger ball heads
0.01 mm year
not good for women or people with reduced kidney function - particles from wear can adversely affect kidney function
Term
hip replacement posterior approach
Definition
access joint from back
preserves hip abductors
more extensive approach
higher dislocation risk
Term
hip replacement lateral approach
Definition
from the side
common
elevation of hip abductors
lower dislocation risk than posterior
occasional improper healing of abductor muscles
Term
hip replacement anterio-laterial approach
Definition
minimally invasive procedure
small incision on the side of the hip
no cutting of muscles or tendons
implant more likely to remain in place
quicker recovery
Term
hip replacement anterior approach
Definition
from the front
reduces dislocation rates in smaller diameter heads
10% rate of numbness due to injury of the Femoral Cutaneous Nerve
Term
hip replacement minimally invasive approach
Definition
double incision
reduces soft tissue damage
visualization and accuracy impaired
comp assisted surgical techniques
Term
nerve palsy
Definition
nerve injury
Term
retroversion
Definition
decrease in torsion angle
Term
antiversion
Definition
increase in torsion angle
Term
cervical spine
Definition
neck
Term
thoracic spine
Definition
back
Term
lumbar
Definition
lower back
Term
lordotic curve
Definition
curves into back, cervical and lumbar spines
Term
kyphosis
Definition
thoracic spine curve
Term
lordosis
Definition
lumbar spine curve
Term
sacrum and coccyx
Definition
tail bone, five fused vertabrae
Term
scoliosis
Definition
deviation in the front/cordonal plane
Term
total number of vertebrae
Definition
25
Term
how many vertebrae in cervical spine
Definition
7
Term
how many vertebrae in thoracic spine
Definition
12
Term
how many vertebrae in the lumbar spine
Definition
5
Term
intervertebral disc
Definition
soft tissue element of spine
Term
vertebrae
Definition
bony element of spine
Term
spinous process (projection)
Definition
bump along back
Term
transverse processes
Definition
two projections on either side of vertebra
Term
laminae
Definition
processes that connect on either side of the spinous process
Term
laminectomy
Definition
removing one or both lamina to relieve spinal cord pressure - often followed by fusion
Term
referred pain
Definition
pain that isn't present at the spine though the nerve cell damage might be at the spine. pinch off nerves between vertebrae and cause pain elsewhere
Term
pedicles
Definition
connect the body of the vertebra with the spinous processes
Term
functional spinal unit (FSU)
Definition
sandwich of vertebra intervertebral disc and vertebra
Term
facet joints
Definition
planar surfaces that come into contact between vertebrae
Term
superior facet
Definition
plane on lower vertebra (upper plane)
Term
inferior facet
Definition
plane on upper vertebra (lower plane)
Term
angle of facet joints near top of spine
Definition
horizontal
Term
angle of facet joints near bottom of spine
Definition
more vertical/less horizontal
Term
elasticity
Definition
tendency for something to return to its original shape after deformation - proportional to displacement
Term
viscosity
Definition
resistance to flow - proportonal to rate of change of displacement
Term
causes of degeneration of intervertebral discs
Definition
rupture in annulus fibers
nucleus pulposus shrinks
herniation of nucleus pulposus
Term
two components of intervertebral disc
Definition
nucleus pulposis and annulus fibrosis
Term
nucleus pulposus
Definition
inner viscous core of intervertebral disc
Term
annulus fibrosis
Definition
anisotropic - layers of fibers that surrounds the nucleus pulposis in the intervertebral disc
Term
process of disc degeneration
Definition
loss of fluid content in disc, loss of viscoelasticity, loss of disc height, vertebral bodies start closing together, close down on nerve roots leaving gaps, bulging disc, partial herniation
Term
spondylolisthesis
Definition
slipping of any two levels
Term
spinal fusion
Definition
connect two or more vertebrae together to increase stability and alleviate pain, commonly lumbar
Term
cons of spinal fusion
Definition
possible non fusion, loss of range of motion and flexibility, stress transfer to adjacent vertebrae,highly invasive
Term
autograft
Definition
tissue from the same person you are implanting it in
Term
WOLFFs law
Definition
response of bone to applied stress - less load - less bone formation
Term
dynamic spinal fusion
Definition
allows some range of motion, higher load on fused joints to allow for bone growth, NOT FDA approved!!!! Failed in too many patients
Term
endoscopic microscopy
Definition
remove small quantities to relieve stress on structures bone might be pushing against, minimally invasive, bandaid procedure
Term
four surgical approaches for spinal fusion
Definition
Lumbar Interbody Fusion (LIF)
anterior, posterior, lateral, transforaminal
Term
off label
Definition
drug or device not FDA approved for the use of the product for a specific use, up to the surgeon and the surgeon ONLY if the device could be successful in patient. Companies CANNOT promote or even suggest off label use. Any consequences that come from off label use are on the surgeon
Term
true/false - all vertebrae are the same size
Definition
FALSE - they become larger as you move downward. Think stress = F/A To keep stress the same with increasing force (due to increasing weight bearing, you must increase the cross sectional area
Term
ACDF
Definition
anterior cervical discectomy fusion
treatment for disc herniation
posterior screws are off label use, anterior is very common (possible paralysis)
Term
two components of ACDF
Definition
cage/spacer
plate
Term
dysphonia
Definition
not able to talk well
Term
dysphagia
Definition
not able to swallow well
Term
PEEK
Definition
common polymer used for disc spacers
Term
spacer
Definition
replacement intervertebral disc
Term
dynamic stabilization
Definition
soft fusion
promotes fusion by small movements
less stress on adjacent levels (adacent disc degeneration is very common with solid fixation)
Term
causes of scoliosis (3)
Definition
congenital
neuromuscular
idiopathic scoliosis
Term
Adam's test
Definition
forward bend test to check for scoliosis
Term
cobb angle
Definition
measurement of degree of side to side spinal curvature
draw line from top and bottom most tilted vertebrae
perpendicular lines from both lines - at intersection, measure angle
Term
cobb angle 15-20 degrees - treatment
Definition
physical therapy and regular check ups
Term
cobb angle 20 -45 degrees - treatment
Definition
back brace
Term
cobb angle over 45 degrees - treatment
Definition
surgical measures necessary - often fuse most of spine -- remove facet joints, vertebrae roughened up to promote new bone growth, eventually fuse together, realigned with metal pins and rods
Term
boston brace
Definition
scoliosis correction
Term
milwaukee brace
Definition
kyphosis correction
Term
IV disc replacement
Definition
using a composite implant to mimic and intervertebral disc
polymer center with metal endplates
Term
true/false - it is more common to use mechanical IV replacement constructs than injectables
Definition
TRUE
Term
Charite
Definition
artificial disc, available angled endplates, increases range of motion
Term
Secure - C
Definition
constrained artificial disc design
15 degrees in flexion extension
10 in lateral bending
unlimited axial
Term
IVD replacement repeat surgery rate
Definition
2-5 years
Term
IVD risks
Definition
material rejection
nerve damage
generally not covered by insurance
Term
mini hip
Definition
short femoral component
Term
total hip replacement
Definition
long femoral component
Term
resurfacing
Definition
young patient, trauma causes damage, replace femoral head ONLY
Supporting users have an ad free experience!