knee

knee flexion during swing functionally ____

shortens limb

slight knee ___ during stances phase allows for ____, convervation of ____ and ___ transmission

flexion, shock absorption, energy, force

knee stability relies more on ____ than ____

soft tissue, shape

tibiofemoral joint

-____ and ____ compartment

-modified ____ joint

-____ degrees of freedom

• ____/____ and ____/___ (voluntary or ___)

medial, lateral, hinge, 2, flexion, extension, internal, external rotation, involuntary

patelofemoral joinr = ___ joint

plane

shaft of femur slants ___ as it descends due to ____

medially, 125 angle of inclinaiton

normal genu valgum = ___ to ___ degrees (measured on ___ side)

170, 175, lateral

angle less than 170 degrees, knocked knee =

excessive genuvalgum

angle greater than 180 degrees, bow-leg =

genu varum

____ at hip can present as ____ at knee

coccavera, genu valgum

proximal fibula

-attachment site for ___ and ___

-forms ___ joint

biceps femoris, LCL, proximal tibiofibular

distal femur osteology: medial and lateral___, ___, ___, ___; ____ notch, ___ groove, ____ surface

condyles, epicondyles, facets, grooves, intercondylar, trochlear, popliteal

proximal tibia osteology: medial and lateral ____, ____ plateau, ___ eminence, anterior and posterior ____ area, ____ tuberosity, ___ line

condyles, tibial, intercondylar, intercondylar, tibial, soleal

patella osteology

-largest ___ bone in body

-base=____ and apex=____

-anterior surface is ____

-posterior surface covered in lots of ___

-posterior surface = ___ facet, vertical ____, ___ facet, ____ facet

sesamoid, superior, inferior, convex, hyaline cartilage, lateral, ridge, medial, odd

articulation between patella and trochlear groove of femur

patellofemoral joint

articular capsule

-relatively ___

-no ___ against hyperextension

-____ and reinforcing ___ may be injured

thin, bony block, capsule, tissues

lines internal surface of the capsule

synovial membrane

reduce friction, up to 14

bursae

associated with bursae, most extensive at suprapatellar and deep infrapatellar bursae

fat pads

____=synovial pleats, most common are ___, ___ and ____ plica

plicae, suprapatellar, inferior, medial

menisci

-____ cavity, provide ____

-____ = no blood supply so ___ healing potential

-____ and ____ horns are anchored to intercondylar region

-____ ligament connects two menisci anteriorly

deepen, stabilty, fibrocartilage, low, anterior, transverse, transverse

two menisci in knee

medial and lateral meinscus

medial meniscus

-___ shaped

-attaches to ___ and capsule

-___ mobile than lateral meniscus so ___ lea-way for stress

crescent, MCL, less, little

lateral meniscus

-___ shaped

-connects to ___ tendon

-___ mobile than medial meniscus

circular, popliteus, twice

menisci blood supply

-red zone - _____ recieves vascular supply from genicular arteries; ___ outcomes for surgical repair

-white zone - ____ no direct blood supply, usually ___ rather than repair because ____ healing potential

outer 1/3, better, inner 2/3, meniscectomy, poor

primary function of menisci = ____

reduce compressive stress

menisi ___ joint contact area, thus ___ force per unit area on bone

triples, reduce

secondary fucntions of menisci (3)

stabilization, proprioception, guiding arthrokinematics

most common mechanism of injury to menisci

rotation on planted leg and flexed knee in excess

-____ tears = most common knee injury

-50% ACL tears have concurrent ____ ____ tears

meniscal, medial meniscus

Medial (tibial) collateral ligament

-resists ___ forces

-superficial part = longer, ___ fibers

-deep part = shorter, ___ fibers

valgus, parallel, oblique

lateral (fibular) collateral ligament

-___-like structure

-from ____ to ____

-resist ____ forces

cord, femoral lateral epicnodyle, fibular head, varus

MCL and LCL

-limit excessive ___ motion

-most taut in ____

frontal plane, full extension

collateral ligaments

MCL, LCL

cruciate ligaments

ACL, PCL

cruciate ligaments

-ACL and PCL cross within ____ notch of femur

-__ joint capsule

-___ blood supply

-resist ___ of all knee motion when act together

-guide ____

-contain ____

intercondylar, inside, poor, extremes, arthrokinematics, proprioceptors

anterior cruciate ligament

-____ area of tibial plateau to medial side of ____

-2 bundles of twisted type ___ collagen

-most taut in ____

-prevents excessive ____ of tibia on femur

-damage with ____ force

anterior intercondylar, lateral femoral condyle, 1, knee extension, anterior translation, shear

most commonly ruptured ligament in the knee

ACL

3 factors for ACL mechanism of injury

1- strong activation of ____ over moderately ____ or nearly ___ knee

2- ____ collapse of the knee

3- excessive ____ of the knee/____ of the hip

quadriceps, flexed, extended, valgus, external rotation, internal rotation

posterior cruciate ligament

-taut with ____

-antagonist = ____

-prevent excessive ___ tibial translation

knee flexion, hamstrings, posterior

PCL mechanism of injury

-typically ____

-fall on to ___

-relatively ____

high-energy trauma, fully flexed knee, rare

voluntary rotation of tibia can happen only when the knee is ___

flexed

involuntary rotation of tibia can only happen when the knee is ___

extending

tibiofemoral joint

-large _____ ____ condyles

-small ____ ____ condyles

-___ degrees of freedom: ____

convex, femoral, nearly flat, tibial, 2, flex/extend, internal/external rotation

flexion/extension: 0 degrees = leg is ____

straight

osteokinematics: rotation of tibia

-important for ____

-____ exceeds ____ by nearly 2:1

functional mobility, exrenral, internal

with rotation, osteokinematic motion is determined by location of ____ relative to ____

tibial tuberosity, anterior distal femur

osteokinematics: external rotation = tibial tuberotisty ____ to distal anterior femur

lateral

osteokinematics: internal rotation = tibial tuberosity ____ to distal anterior femur

medial

screw-home rotation is ____

involuntary

locking knee in full extension requires about 10 degress of ____

external rotation

screw-home rotation

-femur ____ on tibia, or tibia ____ on femur

-knee = ____

internally, externally, extended

screw-home rotation mechanics driven by

-___ of ___ femoral condyle

-passive tension in ____

-slight ___ pull of ____

shape, medial, ACL, lateral, quadriceps

arthrokinematics: knee extension

-tibial on femoral = ____ on ____

-tibial rolls and slides ____

-screw-home rotation: tibia _____ rotates

concave, convex, anteriorly, externally

arthrokinematics: knee extension

-femoral on tibial = ____ on ____

-femoral condyles roll ____ and slide ____

-screw-home rotation: femur _____ rotates

convex, concave, anteriorly, posteriorly, internally

arthrokinematics: knee flexion

-tibial on femoral

-reversal of ____

• tibia ____ rotates

• driven by ____

-____ on ____

-tibial rolls and slides ____

screw-home, internally, popliteus, concave, convex, posteriorly

arthrokinematics: knee flexion

-femoral on tibial

-reversal of ____

• femur ____ rotates

• driven by ____

-____ on ____

-femoral condyles roll ____ and slide ____

screw-home, externally, popliteus, convex, concave, posterior, anterior

arthrokinematics - rotation (voluntary)

-knee must be ___

-arthrokinematics = ____

-____ are compressed and deform slightly

flexed, spin, menisci

patellofemoral joint

-two surfaces: ____ surface on ____ and ___ groove of the ____

articular, patella, trochlear, femur

patellofemoral joint stabilizers (3), main one is ____

quads, joint shape, passive soft tissue restraint, joint shape

common clinical source of knee pain

patellofemoral joint

osteokinematics: patellofemoral joint

-___ motion

-tibial on femoral: patella pulled in direction of ____ during knee flexion

-femoral on tibial: ___ slides on fixed ___

sliding, tibia, trochlear groove, patella

loose packed position of patellofemoral joint

full knee extension

close packed position of patellofemoral joint

mid range flexion

patellofemoral arthorkinematics -135 degrees knee flexion

-patella ____ to trochlear groove

-____ and ____ facet contact femur

-patella contacts femur at ____ pole

inferior, lateral, odd, superior

patellofemoral arthorkinematics -90-60 degrees knee flexion

-patella ____ with trochelar groove

-most ___

engaged, stable

patellofemoral arthorkinematics - 20-30 degrees knee flexion

-patella ___ femur at inferior pole

contacts

patellofemoral arthorkinematics -0 degrees knee flexion

-patella completely ____ to trochlear groove

-_____ moveable retaliative to femur

proximal, freely

accessory patellar kinematics: patellar ___, ___, ___

tilt, spin, shift

patellar tilt: ___ plane of rotation, ____ axis, tilt ____/___

horizontal, vertical, medially, laterally

patellar spin: ___ plane of rotation, ____ axis, apex pointed ___ or ___

frontal, ant-post, right or left

patellar shift: ___ plane of rotation, ___ axis, shift ___/___

frontal, med-lat, medially, laterally

____ have 3x greater CSA than ____

-_____ torque is greater

-_____ pulls medially on patella

-_____ pulls laterally on patella

quads, hamstrings, extension, vastus medialis, vastus lateralis

isometric action of quads

stabilize knee

eccentric action of the quads

-_____

-controls _____

-forces up to 7x body weight through ____ when ____

shock absorption, rare of knee flexion, patella, landing

concentric action of the quads

extends knee

tibial on femoral extension: when the knee is in 90 degrees of flexion:

-_____ external moment

-line of gravity = ____

no, through tibia

tibial on femoral extension: when the knee is in 45 degrees of flexion:

-____ external moment

-line of gravity = _____

increasing, through center of mass of moving segment

tibial on femoral extension: when the knee is in 0 degrees of flexion (full extension):

-_____ external moment

-internal forces ___

-most quads force = greater _____

longer, increase, patella femoral compression

femoral on tibial extension

-first 90 degress = ____ external moment

-about 45 degress = ____ external moment

-0 degrees = _____ external moment

greatest, smaller, no

the patella provides a better _____ because it _____ extension torque potential by allowing a ____ internal moment arm

mechanical advantage, increases, longer

the patellofemoral joint increases compression forces with increased ____ and ____

quadriceps force, knee flexion

contracting quads pulls patella ____ into trochlear groove and slightly ____ and ____

superiorly, laterally, posteriorly

angle between force vector of quads and long axis of patellar tendon

q angle

measure relative lateral pull of the quads on patella

q angle

excessive ____ tracking is common cause of patellofemoral joint pain

lateral

optimal patellar tracking

-movement between patella and femur is across ____ area with ____ stress

greatest possible, least possible

excessive lateral tracking ___ contact area which ___ stress throuhgout articular surface, which ____ risk for dislocation

reduces, increases, increases

local factors that pull patella laterally

-____

-____ force on the patella

-lateral patellar ____ fibers

-____ muscle

iliotibial band, bowstring, retinacular, vastus lateralis

local factors that pull patella medially

-____ muscle

-raised lateral facet of ____

-medial patellar ____ fibers

vastus medialis, trochlear groove, retinacular

excessive ____ or _____ increases q angle

-caused by laxity in ___, weak ___, excessive ____ of subtalar joint

coxavara, genu valgum, MCL, hip abductors, pronation, eversion

excessive lateral patellar tracking can be caused by excessive ____ load

-causes: ___ rotating femur on ____ lower leg, compensation for excessive femoral ____ or excessive tibial ____, excessive ___ of subtalar joint

valgus, internally, fixed, anterversion, external torsion, pronation/eversion

knee flexor-rotator muscles

-____ decelerate advancing lower leg during late swing phase so we don’t forcefully ___

-rapidly ___ to accelerate knee ___ during sprinting

-dynamically ____ knee

eccentrically, extend, contract, flexion, stabilize

3 knee flexor-rotator muscles

hamstrings, pes anserinus, popliteus

main function of popliteus

-_____ and ____ rotates extended knee (_____ the knee)

flex, internally, unlocks

contributing factors to excessive genu valgum

-____ alignment

-previous ____

-weak hip ______

bony, injury, abductors