MSK knee Flashcards
(160 cards)
what are the 3 joints of the knee?
tibiofemoral
patellofemoral
tibiofemoral
what is the primary WB joint of the knee?
tibfem
guides flex/ex and IR/ER
what is the primary WB structure in the frontal plane?
medial condyle
describe the medial condyle in the sagittal plane?
longer by 1/2 inch
drives screw home
what is the pathway of patella tracking?
begins slightly proximal to the femoral sulcus
lateral contact guides the patellar to full contact at 30 deg
tracking forms a subtle C pattern lat/med/lat
what does patellar tracking depend on?
bony architecture of femoral sulcus/patellar
extensibility of surrounding CT
quadriceps activation
what are the mvmts of the patellofemoral joint?
superior (ext)/inferior (flex) glide
medial/lateral glide
medial/lateral tilt
medial/lateral rotation
describe the tib fib joint
NWB, 3mm of mvmt
post to tibia
fibular nerve wraps around its head
describe ACL
dynamic stabilizer of the knee
load is highest in ext
two bundles - postlat - ext, antmed - flex
anterior tib translation resisted by ACL
describe the innervation and vascularization of ACL
tibial nerve
middle genicular artery
describe PCL
dynam stabilizer
20% bigger than ACL
loaf highest in flexion
resists post tib translation
two bundles - antlat(thicker) - flex, postmed - ext
ER stabilizer
less commonly injured
originates on med fem condyle
describe MCL
limits valgus
bolstered by pes an and semimem
describe the superficial MCL
primary valgus stabilizer
taut at end ranges
semimem and post oblique lig
describe the deep MCL
stab valgus and may help with ant translation
taut in ext
meniscofemoral and meniscotibial ligs
describe LCL
resist varus
near to popliteus
bolstered by anterolateral lig - poor man’s ACL
bolstered by IT band
describe the posterior knee
durable post capsule and obl popliteal lig resists hyperext
has a release valve for synovial fluid
has rotational instability after ACL/PCL injury
what is in the posterior lateral corner?
LCL
popliteus
arcuate lig
biceps femoris
describe the menisci
stability, cushion, nutrition, proprioception to knee
attaches to: quads, semimem, bifem, capsule, MCL
which men moves more?
lateral
where is vascularity the worst in the menisci?
the MIDDLE
outside 10-30% is well vascularized
what are the roles of the other parts of the LE?
trunk - stability
hip - force generation - big butt muscles
knee - force modulation - cannot work alone
ankle/foot - force transmission - react to ground
what are the muscles that cross the knee?
IT band
quads
hams
gastroc
gracilis
sartorius
add mag
all long muscles
poor stability
great force generation
describe the posterior innervation of the knee
sciatic nerve - sacral plexus
common fibular
superficial fibular - lat leg
deep fibular - ant leg and dorsum of foot
tibial nerve - post leg and plantar of foot
sural nerve - sensory only
describe the anterior innervation of the knee
femoral - lumbar plexus - ant thigh
anterior cutaneous - prox sen
saphenous - dist sen
obturator - lumbar plex - med thigh
lateral cutaneous - lumbar plex - sen of lat thigh