Anatomy (PT) KNEE

oblique popliteal ligament

- expansion of semimembranosus tendon - reinforces posterior knee especially in area of intertrochanteric

facet

part of a bone that articulates with another bone

bakers cyst

popliteal bursa can get a buildup of synovial fluid

MCL

primarily resists VALGUS stress -taut in full extension -also resists lateral tibial rotation and medial femoral rotation

LCL

primarily resists VARUS stress -also taut in full extension -also resists lateral tibial rotation and medial femoral rotation

patellar ligament

strong fibrous band -maintains alignments of patella -receives medial and lateral retinacula (therefore it also plays a role in keeping patella in correct alignment during motion)

Q-angle

the valgus angulation between the pull direction of the quadriceps m and patella tendon

based

top of patella (wider portion)

deep (has fibers that blend with medial meniscus) superficial (more vascularized and first to be injured)

what are layers of the MCL

rectus femoris, hamstrings -hip position may affect force output of these muscles across the knee -hip position may affect ROM measurements across the knee

what are some considerations for two joint muscles regarding the knee and hip

tibiofemoral patellofemoral proximal tibiofibular

what are the 3 joints of the knee complex

inferior aspect of patella to tibial tuberosity

what are the attachments of the patellar ligament

superolateral: biceps femoris superomedial: semiten/semimem inferolateral: lateral head of gastroc inferomedial: medial head of gastroc

what are the boundaries of the popliteal fossa

termination of small (lesser) saphenous v. -popliteal artery and vein -tibial nerve -common peroneal nerve -posterior cutaneous nerve (of thigh) -popliteal lymph nodes and vessels

what are the contents of the popliteal fossa

anterior-medial bundle (most taut in flexion) posterior-lateral bundle (most taut in extension)

what are the functional bundles of the ACL

deepen joint surface and increase congruency/contact area -absorb shock -distribute weight-bearing/load transmission -provide stability -aid in lubrication of joint

what are the functions of the menisci

Ligament of Humphrey ligament of wrisberg (most people have one or the other)

what are the menisocofemoral ligaments called

tibial nerve: posterior compartment, mostly innervates nerve that plantar-flex ankle deep peroneal nerve: goes into anterior compartment (dorsiflexors) superficial peroneal nerve: goes into lateral compartment (evertors)

what are the nerves of the compartments of the lower leg

arcuate popliteal ligament popliteus muscle oblique popliteal ligament

what are the posterolateral corner stabilizers

roof: skin and fascia floor: femur, knee joint capsule, popliteal fascia

what are the roof and floor of the popliteal fossa

medial: MPFL, some fibers of vastus medialis lateral: vastus lateralis, blends with retinaculum and blends a little with IT band

what are the structures that cause medial and lateral patellofemoral tracking

sartorius, gracilis, semitendinosus

what are the tendons of the pes anserine in the CORRECT order

if someone hits your lower leg forward or your upper leg backwards

what are two ways that your ACL could be torn

the MCL is injured more frequently because its attached to MCL and there is less ability to slide out of the way

what collateral ligament is injured more frequently

MCL, therefore is injured more

what collateral ligament is weaker, MCL or LCL

they both secondarily help limit internal rotation of tibia (AKA external rotation of femur)

what do the ACL and PCL do in regards to hip rotation

the two bundles wind around each other to become tighter

what do the bundles of the ACL do when the knee is in motion

anterior: ankle eversion posterior: ankle inversion

what does posterior glide and anterior glide of the tibiofibular joint accompany

medial facet is larger than the lateral facet (50% larger)

what facet of the knee is larger

infra-patellar fat pad

what fat pad of the knee is often most problematic

superficial, but has a better vascular supply so is more likely to heal on its own

what fibers of the MCL are injured more frequently

lateral patellar tracking is more common.

what happens more often lateral or medial patellar tracking?

the part of the patella that is touching the femur changes

what happens to the contact area of the femur and patella as the knee moves between flexion/extension

open packed -minimizes influence of bony architecture, menisci, and hamstrings in providing additional stability

what is better when testing ligaments, the open or closed pack position?

full extension

what is considered the most stable position of the knee

ACL is weaker, poor blood supply and will likely not heal on own

what is structurally weaker between the cruciate ligaments

it depends on the position the knee is in. -when the knee is flexed slightly IT band acts as a secondary knee extensor -once your knee is flexed past 30 degrees the IT band acts as a secondary knee flexor

what is the action of the IT band

open packed: 30 degree flexion closed packed: full extension

what is the closed and open packed position of the tibiofemoral joint

protects the anterior knee -increase the mechanical advantage of the quadriceps muscle

what is the function of the patellofemoral joint

stabilize posterolateral corner. if these are injured, you get a " "rotary instability' (tibia is rotating too much unde femur)

what is the main function of the arcuate popliteal ligament

anterior transverse meniscomeniscal

what is the most common

menisci glide anteriorly with extension; posteriorly with flexion

what is the motion of menisci during extension and flexion

popliteus. contracts the unscrew the knee (ruled more important in weight bearing)

what is the muscle responsible for "unlocking" the knee

men: 14 degrees women: 17 degrees (women are higher because wider pelvis for childbirth)

what is the normal Q angle range

Intracapsular but extrasynovial (inside joint capsule but not inside synovial membrane. therefore do not get nutrition from synovial membrane)

what is the nutrition of the cruciate ligaments

open packed: full extension closed packed: full flexion

what is the open/closed packed position of the patellofemoral joint

epicondyles are on top condyles are below

what is the positioning of the epicondyles and condyles

limit anterior translation of tibia from under the femur (aka posterior translation of femur on tibia)

what is the primary function of the ACL

limit posterior translation of the tibia on the femur (aka anterior translation of femur on tibia)

what is the primary purpose of the PCL

both menisci have coronary ligaments, they attach meniscus on tibia (holds down onto tibia)

what is the purpose of the coronary ligaments

serve as secondary restraint to posterior tibial translation

what is the purpose of the meniscofemoral ligaments

improve line of pull of the quadriceps muscle and give it more mehcnaical advantage -can create more movement with less force -makes lever longer

what is the purpose of the patella

innervated with mechanoreceptors -tell brain when ligament is taut and in dangerous position for injury. -position and/or veloicty info during movement

what is the sensory role of capsule and ligaments

modified plane joint (functions mostly like a regular plane joint. gliding and sliding)

what kind of joint is the patellofemoral joint

bicondylar synovial joint (allows flex/ex, ER/IR)

what kind of joint is the tibiofemoral joint

plane synovial joint (can bear 1/6 weight)

what kind of joint is the tibiofibular joint

medial meniscus attaches to MCL lateral meniscus does NOT attach to LCL

what meniscus attaches to what collateral ligament?

biceps femoris IT band

what muscles are responsible for lateral tibial rotation

pes ans med ham popliteus

what muscles are responsible for the medial tibial rotation in NWB

inner 1/3 doesnt have blood supply outer 1/3 has blood supply (middle can be hit or miss)

what part of the menisci has blood supply

frontal plane movement (valgus and varus)

what plane of movement do the collateral ligaments prevent?

bicondylar "modified hinge joint"

what type of joint is the knee joint

during 20, 45 and 90 degrees of flexion

when are lateral and medial facets of the patella touching the femur?

when you are in flexion, the patella is nestled into trochlear groove on femur. when you are in extension, patella is not in groove and is just resting on top. also ligaments that help hold patella in place are tighter in flexion and don't allow much movement

when is it easier to move the patella? why?

OKC: greater from 0-45 degrees CKC: from 45-90 degrees

when is the PFJR and contact stress greater in OKC and CKC exercises

when the knee is extended

when is the bony congruity the best at the knee

at end range flexion, patella will tilt toward the medial side and this is when odd facet is touching.

when is the odd facet of the patella the ONLY facet touching the femur

the external margins

where does the mensici have thicker margins

because of the poor bony congruency

why are ligaments so important in the knee

important in the knee since the bone congruity is so poor

why are the menisci so important

yes they have a great blood supply, can head and can hurt if injured

are fat pads vascularized?

fibrous capsule (of joint capsule)

arises above the femoral condyles and blends with ligaments and musculature

meniscomenical ligaments (4 types)

attach meniscus to each other how many types of these?

synovial capsule (of joint capsule)

attaches to the edges of articular cartilage and below the menisci

apex

bottom of patella (narrower portion)

genu varus

bow legged

yes. they are both taut in extension, therefore a hyperextension force could result in injury to both

could the MCl or LCL be injured in a hyperextension MOI?

femur moving on tibia convex on convace --> roll and glide in OPPOSITE direction extension: anterior roll/post. glide flexion: posterior roll/ant. glide

describe the arthrokinematics of the tibifemoral joint for CKC

tibia moving on femur concave on covex --> roll and glide in SAME direction extension: anterior roll AND glide flexion: posterior roll and posterior glide

describe the arthrokinematics of the tibiofemoral joint for OKC

epicondyles do not fit well into condyles (poor bony congruity) stability comes from ligaments and muscle strength, due to poor bone congruity

describe the bony congruency of the knee joint

contact area goes from distal to proximal on surface of patella as the knee is flexed -contact area becomes larger as knee is flexed

describe the contact areas of the patella

full extension: no contact between patella and femur -as you begin to flex, the most inferior portion (apex) of patella will start contacting femur. -as you continue flexing, will move superiorly on patella

describe the contact of the patella and femur during flexion and extension

most motion occurs in flexion/extension -little rotation is available

describe the motion in the knee joint

-increased flexion moment arm of gravity or external resistance -quads have to create more force to do exercise -PFJR force peaks at 35 (most compressive) -decreased contact area results in increasing contact stress from 90 to 20 degree of flexion

describe the patellofemoral biomechanics during open chain leg extension, free weight

10-15 degrees of lateral tibial rotation at end range extension

describe the screw home mechanism for non weight bearing

10-15 degrees of femoral medial rotation at end range extension

describe the screw home mechanism for weight bearing

popliteal fossa

diamond shaped depression of the posterior aspect of the knee

no, popliteus is in the way

does the LCL attach to the lateral meniscus or capsule

extension: patella glides superiorly flexion: patella glides inferiorly

during extension and flexion of the knee what way does the patella glide?

plica

extra bits of synovial tissue, where synovial membrane folds over on itself

menisci

fibrocartilaginous structures -made up primarily of type 1 collagen -collagen bundles arranged outside to inside -radial fibers woven in between

arcuate popliteal ligament

head of fibula, splits in tow. one goes to femoral condyle/ epicondyle, other goes into blend with oblique popliteal

VMO (Vastus Medialis Oblique)

helps stabilize patella on medial side. -you CANT't isolate this

named for how they attach on the TIBIA

how are they cruciate ligaments named?

they are somewhat enclosed by fibrous capsule, NOT inside synovial joint (cant get nutrition from synovial knee joint, means capacity for healing is relatively poor)

how do the ACL and PCL fit within joint capsule

anterior intercondylar region of tibia, travels superiorly and laterally to attach to lateral condyle of femur

how does the ACL travel and attach on the tibia and femur

posterior intercondylar area of tibia, travels superiorly and anteriorly and attaches to medial condyle of femur

how does the PCL travel between the tibia and femur

angle from ASIS to center of patella to tibial tuberosity

how is Q angle measured

genu valgus

knock knees (relative to hips) knee are in and feet are out

flexion > extension restrictions

A person with a capsular pattern at the tibiofemoral joint will lose more flexion or extension?

Menisofemoral ligaments

ligaments that attach lateral meniscus to femur