Knee Flashcards by Siva Pye

Extensor lag:

Functional role of _____

A “______” between femur and quads

Increases the ______ moment arm of the _______ mechanism

> est between ___-____ deg

patella

spacer

internal

extensor

20; 60

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Reasons for PF alignment

______
Local factors: act _____ on the PF joint
Global factors: related to ________ of the bones/ joints of LE

Quadriceps
directly
alignment

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How can this happen? Slide with valgus unilateral stance

Laxity/injury to ______

Dynamic posture of ______ of femur (weak hip _______/tightness of add; ________ Trendelenburg and GRF shift to ______ knee creating a ______ torque; excessive ______ of ST joint (____ of tibia) reduced strength/neuromuscular control of ______ of hip (thus _____ of femur)

MCL

ADD

ABD

compensated

lateral

valgus

pronation

IR
ER
IR

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Capsule and Reinforcing
Ligaments

Connective tissue reinforcement:
_______ popliteal lig, _______ popliteal lig

Muscular reinforcement: _______, ________, _______ (esp ___)

oblique
arcuate

popliteus, gastrocs, popliteus, hamstrings, SM

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Connective tissue reinforcement:

Medial: from ____ tendon to ______ capsule medial slide

Muscular- _______ /_______/_______ ______

patellar

posterior

SM
SGT
pes anserine

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TF joint: Meniscisi

large _____ femoral condyles and flat, smaller ______plateaus

Excessive motion but soft tissue provides ______ – thus injury can involve many structures

act as _______ to form seats for the femoral condyles

convex
stability
gaskets

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Menisci are anchored to ________ region of tibia @ ______/______ horns

intercondylar
anterior/posterior

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External edge of each meniscus is attached to tibia and the capsule by _______ ligaments (meniscotibial) – these are loose allowing pivoting

coronary

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The 2 menisci are connected anteriorly by ________ ligament

transverse

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Secondary attachments of muscle to menisci

_____
_____
______ to lateral

SM
Quads
popliteus

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Meniscus

Medial oval shape attaches to ______ and ______ capsule

Lateral more circular, only attaches to _______ capsule, popliteus passes between LCL and LM

MCL; ajacent

lateral

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Blood supply; peripheral 1/3 is called the “_____ zone”

inner 2/3 avascular and called the “_____ zone”

red

white

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TF joint:
decreases ______ forces (triples joint contact area and decreases pressure on ______ cartilage)

compressive
articular

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TF joint:

WB is ______- meniscus deform peripherally (_____ _____-) becomes ________ stress

Compressive force at knee walk ____-_____x BW and > ____X with stairs

axial
hoop stress
tensile

2.5-3
4

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TF joint:

complete lateral ______ increases peak contact pressure 230%

meniscectomy

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TF secondary functions:

_______ joint during motion

_______ articular cartilage

providing _______

stabilizing
lubricating
propiception

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________ have been identified in the anterior and posterior horns of menisci

mechanoreceptors

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Meniscal tears (common)

Often associated with _____, _____ rotation of femoral condyles over a fixed ____ knee (can pinch and dislodge _____)

A dislodged or ____ _____ (bucket handle) can mechanically _____ knee motion

Medial injured _____ as frequently- _____ force (large stress on ____/post/med capsule)

Risk increases with ligamentous _____ (esp ACL) and malalignment

forceful
axial

WB
meniscus

folded flap
block

2x
valgus
MCL

laxity

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TF joint: Osteokinematics

FLX/EXT

_____ degrees of freedom (F/E and ROT)

Knee must be slightly _____ to have rotation occur

Frontal plane is passively only ___-____ deg

___/___ axis (sagittal plane)

____-_____deg FLX
____-_____ deg hyperext

2
flexed
6; 7
ML
130; 150
10

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TF: Osteokinematics

IR and ER

Axial rotation: ________ axis through tibia
(influenced by _____ plane motion) little in EXT

At 90 deg: ____-____ deg of axial rotation; ER __:__ exceeds IR

Rotation named by position of ______ ______ relative to anterior ______ femur

longitudinal
sagittal
40; 45
2; 1
tibial tuberosity
distal

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TF joint: FLX/EXT Tibial on femoral: EXT- tibia rolls and slides ______ on femur; meniscus pulled anteriorly by ______

anterior quads

TF joint: FLX/EXT Femoral on tibial EXT- femoral condyles roll _____ and slide _____ on tibia; quads direct the _____ and stabilizes the ______ vs _______ shear of femur

anteriorly posteriorly quads meniscus posterior

"Screw home" mechanism: Full EXT requires ____ deg of ______ during the last _____ deg of ______ (linked and not independent motion); increases joint ______/________ OC tibia _____; CC femur ____

10 ER 30 EXT congruency; stability ER IR

"Screw home" driven by: 1. shape of _______ ________ (tibial follows medial condyle and creates _____) 2. Passive tension of ____ 3. Slight pull of _____

femoral condyle ER ACL quads

Relating to "screw home" Flexion is opposite: the unlocking _____ happens 1st and driven by the _______ (can rotate the femur or tibia)

IR popliteus

TF Joint: Arthokinematics IR/ER Knee must be _____ Spin between the _____ and _____ surfaces of tibia and femur Axial rotation of _____ over ______ causes menisci to deform/compress ( ______ and ______ help stabilize)

flexed menisci; articular femur; tibia popliteus; SM

______ flat and broad has a superficial and deep part Superficial: well-defined parallel fibers @ 10 cm med epicondyle to med pat retinaculum fibers to med proximal tibia Deep: slightly posterior and distal: shorter and oblique attaches to capsule/medial meniscus/SM tendon

MCL

_____ ligament Short cord-like Runs vertical lateral epicondyle femur to head of fibula Does not attach to the adjacent meniscus (tendon of popliteus runs between them) Distally it blends with tendon of biceps femoris

LCL

Functional considerations for MCL and LCL Primary: limit motion in _____ plane Knee extended: _____ vs valgus. force, LCL vs _____ force

frontal MCL Varus

Functional considerations for MCL and LCL Secondary: provide general ______ tension especially walking near EXT and _______ Protect against ROT extremes (_____ at extreme ER)

stability loading MCL

Most common mechanism of injury for _____ ligament 1. valgus producing force with foot planted "clip" 2. severe hyperextension

MCL

Most common mechanism of injury for _____ ligament 1. varus producing force with foot planted 2. severe hyperextension of knee

LCL

Most common mechanism of injury for _____ ligament 1. hyperextension of combined hyperextension with ER of knee

PCL

Most common mechanism of injury for _____ ligament 1. Large valgus- producing force with foot firmly planted 2. Large axial rotation torque applied to knee (either rotation) 3. Any combination above, especially involving strong quad contraction with knee in near EXT or full EXT 4. Severe hyperextension

ACL

Most common mechanism of injury for _____ ligament 1. Falling on a fully flexed knee (ankle PF) 2. Any event that causes a forceful posterior translation of tibia or ant translation of femur, esp with knee flexed 3. large axial rotation, valgus-varus torque with foot planted, especially with knee flexed 4. Severe hyperextension

PCL

ACL and PCL _____ within the intercondylar notch intracapsular, _____ by extensive synovial membrane ______ blood supply Named for attachment on tibia ( ______ and _____) Together resist extremes of all motions- but primarily ___/____ shear forces between tibia and femur in sagittal plane motions cutting (_____ and ______ planes) Helps guides arthrokinematics and provides propiceptive feedback (________)

cross covered poor thick; strong AP frontal; horizontal mechanoreceptors

ACL _______ tibia Runs ____/_____/_____ to medial side of lateral condyle Collagen fibers _____ on each other Some fibers are taut in ______ but increasingly taut in _____ (esp ___-____ bundle)

anterior sup/post/lat twist flexion ext posted

ACL Last ____- _____ deg of EXT the force of quads pulls the tibia _____

50; 60 anterior

Anterior drawer test: _____ spasm could prevent good test

Common mechanism of injury ACL ______ spatial orientation and multiple ____ bundles... may directions to resist Is highly vulnerable if _____ in extremes of motion (high velocity) Factors: speed and direction GRF, amount of direction of compressive and _____ forces; control and ____ of muscular forces; _____ and strength issues; ______ of trunk and lower limb Most requently _____ lig in knee

Oblique multiple tensioned shear timing integrity alignment ruptured

70% of sports injuries are related to ___-____ ACL

non-contact

Strong quad activation: can cause "____" collapse and excessive _____ (femur IR)

valgus ER

PCL Majority becomes increasingly taut with greater _______ (___-____ deg >est) Slack in ___/____ deg into EXT Limits _____ glide

flexion; 90; 120 30; 40 posterior

Knee extension: quadriceps innervated by _____ nerve

femoral

Knee Rotation: Internal: - Sartorius ( ) - Gracilis ( ) - SM ( ) - ST ( ) - Popliteus ( ) External Biceps femoris ( )

femoral obturator sciatic sciatic tibial sciatic

Knee Flexion: SM ( ) ST ( ) Bicep femoris ( ) Sartorius/Gracilis ( / ) Gastrocnemius/Plantaris ( ) Popliteus ( )

sciatic x3 femoral; obturator tibial tibial

Largest afferent to knee _____ _____ nerve

posterior tibial

afferent fibers in _______ nerve Carries sensation from skin over medial knee and post/post-medial capsule afferent fibers in ________ nerve Carries sensation from ant-medial and ant-lateral capsule

obturator femoral

_______ _______ - AIIS & immediately superior to acetabulum Vastus _______ - est cross sectional area Vastus _______- extends farther toward the knee, 2 sections Vastus _______ - deep to RF and VL ________ _______ - deep to VI, poorly defined, runs distally into the capsule/synovial membrane (pulls them prox during ext)

Rf Lat Med Intermed Articularis genu

RF VL VM VIM forms strong ______ tendon _______ tendon connects apex to tibial tuberosity

quadriceps patellar

Functional considerations _________ functions: stabilizes to protect the knee ________ functions: controls the rate of descent of the body’s COM (sitting, squatting landing from a jump) controls the rate of descent of the body’s COM (sitting, squatting landing from a jump) Step down ________ functions: Accelerates tibia/femur toward extension…raises COG: jump, step up, stand up, running uphill.

isometric eccentric concentric

______ torque External load (item being held) *blue _______ torque Muscle force X its internal moment arm (red) The ET must be met or exceed by an opposite _____

external internal IT

The ______ muscle unlocks the knee when walking, by ______ ROT the femur on tibia during _____ chain OC: it _____ rotates the tibia on femur

popliteus laterally CC medially

Knee Flexors- Rotators _______, ______, ______, _______ all flex and rotate (gastroc only non rotator) Roatation- IR (___/____) ER (____)

HS sartorius popliteus gracilis SM/ST/ BF

Knee flexors- Rotators Sartorius/Gracilis -_____ _____- posterior to knee axis- so IR; medial knee (resists knee ____ and _____ loads_

pes anserine ER Valgus

Popliteus screw home unlocks the knee by either ________ rotating the femur or _______ rotating the ______

externally; Internally tibia

EROT @ knee short head of ____ _____ contracts to accelerate the femur ______ Active force from the pes anserinus muscles in conjunction with a passive force from the stretched medial collateral ligament (MCL) and oblique popliteal ligament (not shown) helps to ______

biceps femoris internally decelerate

Genu recurvatum is > ___ deg of hperextension LOG is _____ to knee Poor _____ control, _______ disease- spasticity of quad/weakness of flexors; ______/laxity

10 anterior postural neuromuscular overuse

ACL and rehab Avoid exercises where _____/_______ quad contractions create _____ translations of the tibia early on rehab to damage tissue Muscle line of force changes with _____ angle Risk is when force in _______ to ACL action and muscular force magnitude increases

repetitive/ strong flexion opposition

Gastroc and Plantaris Action: Nerve:

Knee FLX

Biceps femoris (short head) Action: Nerve:

Biceps femoris (long head) Action: Nerve:

Semimembranosus and tendinosus Action: Nerve:

Knee FLX and IR Sciatic

Popliteus Action: Nerve:

Knee FLX and IR tibial

Quad femoris Action: Nerve:

Knee EXT and Hip FLX Femoral

Vastus Group Action: Nerve:

Knee EXT Femoral

Sartorius Action: Nerve Gracilis Action: Nerve:

Knee FLX and IR femoral Knee FLX and IR obturator