Shared Flashcard Set

Details

knee part 1
knee part 1
177
Anatomy
Graduate
09/30/2012

Additional Anatomy Flashcards

 


 

Cards

Term
when someone's knee is swollen, why does it look swollen above the knee?
Definition
synovial joint space continues above the knee
Term
what type of joint is the tibiofemoral joint
Definition
synovial hinge joint
Term
what is the normal range of extension - flexion of the tibiofemoral joint
Definition
0-135
Term
what is the normal range of medial rotation of the tibiofemoral joint
Definition
20-30
Term
what is the normal range of lateral rotatoin of the tibiofemoral joint
Definition
30-40
Term
what are the functions of the tibiofemoral joint
Definition
support, mobility
Term
what is medial/lateral rotation of the tibiofemral joint?
Definition
tibial rotation. Tibia rotating on the femur
Term
what are epicondyles
Definition
small points facing to the sides. On condyles
Term
what attaches to the lateral femoral epicondyle
Definition
lateral collateral ligament and popliteal muscle
Term
when looking at knee ROM, what should be the center fo the axis of measurement/rotation
Definition
epicondyles
Term
how much knee flexion is needed for gait
Definition
60
Term
how much knee flexion is needed for stairs
Definition
70-80
Term
how much knee flexion is needed for sitting
Definition
90
Term
how much knee flexion is needed for bicycling
Definition
110 deg
Term
what is the normal angle of the knee in the frontal plane
Definition
6-10 valgus
Term
how much valgus is called valgus
Definition
10 deg
Term
how much valgus is called varus
Definition
<5
Term
is the medial or lateral femoral condyle surface area larger
Definition
medial femoral condyle has larger surface area
Term
in open chain, what causes screw home mechanism locking?
Definition
tibial external rotation. In open chain, you're moving the tibia on the femur. As you go up into extension, the locking mechanism occurs as the quad pulls tibia up in space to 0 deg extension. Motion on lateral condyle finishes first, but there's still room to go on medial condyle so quads continue to pull. As movement continues on medial side, tibia externally rotates.
Term
what unlocks the screw home mechanism in open chaing
Definition
relaxation/eccentric control of quads
Term
what locks the screw home mechanism in closed chain?
Definition
femoral internal rotation. The quads lift a person up into extension by pulling the femur on top of the tibia. As you go up into extension, the knees extend to 0 deg, the motion on the lateral side of the knee stops first. The tibia is fixed on the ground and the femur is moving on top of the tibia. The femur will medially rotate to put the tibia in relative external rotation.
Term
what unlocks the screw home mechanism in closed chain
Definition
popliteus muscle laterally rotates the femur to unlock the knee
Term
what is the close pack position of the knee
Definition
full extension with lateral tibial rotation (screw home position)
Term
what makes full knee extension its close packed position
Definition
most congruent joint surfaces, least amount of joint space, tightest ligaments
Term
what is the resting position of the knee
Definition
25 deg flexion
Term
what is the capsular pattern of the knee
Definition
flexion > extension
Term
at what position are both bands of the ACL relaxed
Definition
20-30 deg tibfib flexion
Term
what position do people assume when the knee swells
Definition
25 deg flexion
Term
what to ask for in the history portion of the examination
Definition
mechanism of injury; past medical history/other episodes; 24 hour cycle; pain location/type/aggs/alleviating factors/functional limitations/shoe wear, assistive devices, bracing, orthotics/other pertinent history, meds, diagnostic tests, training history, surface conditions
Term
what to ask about catching in the knee
Definition
where is the knee when this happens?
Term
what to ask about the knee giving away
Definition
where does it happen? Can you catch yourself?
Term
what happens when the knee gives way
Definition
painful structure gets a lot of stress, shuts the muscles off
Term
what to ask about shoe wear?
Definition
does a different pair make it better or worse?
Term
what are the ligament injury grades?
Definition
trace, grades 1-3
Term
describe a trace liganemt injury grade
Definition
normal joint play. 1-2mm or so. Different for different joints
Term
describe a grade I ligament injury
Definition
mild injury with integrity maintained. 0-25% injury. Up to 5mm. Pain. Solid end feel
Term
describe a grade II ligament injury
Definition
moderate injury with partial integrity loss. 25-75% of the structure is injured. 6-10mm of movement. Painful with either solid or muschy end feel
Term
describe a grade III ligament injury
Definition
severe injury with complete rupture. 75-100% of the structure injured. >10mm. There may be no pain because the whole thing's torn. There is nothing left that's connected.
Term
Medial collateral ligament is the primary restraint for what?
Definition
valgus stress at 0 degrees.
Term
MCL is a secondary restraint for what
Definition
anterior displacement, rotation, hyperextension
Term
the deep fibers of the MCL attach to what structure?
Definition
medial meniscus
Term
what is the functional interference of the MCL?
Definition
inability to turn quickly
Term
where is the posterior oblique ligament?
Definition
behind the MCL. Goes from femoral condyle to medial tibial condyle. External to the semimembranosus
Term
what is the primary restraint of the posterior oblique ligament?
Definition
restrains valgus in flexion and hyperextension
Term
what is the secondary restraint of the posterior oblique ligament
Definition
valgus stress at 0 degrees.
Term
when the knee is in flexion, is the MCL or posterior oblique ligament a greater restraint to valgus force?
Definition
posterior oblique ligament
Term
what is the mechanism that causes medial knee joint instability?
Definition
valgus force in weightbearing. Force comes into the lateral side of the knee. Knee pops open medially.
Term
how to test for medial joint instability
Definition
generally, the same way it was injured. Apply valgus force
Term
what ligaments are tested when you apply a valgus stress to the knee at 0 deg extension
Definition
ACL, PCL, mcl, pol
Term
what ligaments are tested when you apply a valgus stress to the knee at about 30 deg flexion
Definition
MCL, POL
Term
what other tests might be positive with medial joint instability?
Definition
pivot shift, lachman
Term
will there be joint line tenderness with medial joint instability
Definition
yes
Term
what kind of force can injur medial knee ligaments in open chain?
Definition
medial force to the ankle
Term
when will there be pain with medial knee instability
Definition
end range flexion/extension
Term
what will the ROM be like with medial joint instability
Definition
significantly restriceted with grade II-II tears
Term
what intervention to do for Grade I medial jiont instabilty of knee
Definition
treat for pain and swelling. May choose to brace to reduce pain. RICE, estim, ultrasound
Term
describe a grade I medial joint instability
Definition
medial swelling. It hurts when they walk, run, turn. Structure is intact, only need to control pain and swelling.
Term
what to do if someone has a grade II or III medial joint instability
Definition
try to approximate ends of tissue, immobilize, and refer to orthopod
Term
do all grade II, III medial knee instabilities require surgery
Definition
no
Term
should early weightbearing be considered in medial knee instability and why/why not?
Definition
yes. Helps maintain quadriceps
Term
why should someone with grade II/III medial jiont instbaility wear a brace
Definition
helps prevent excess motion
Term
how long should someone with Grade I tear wait to return to activity
Definition
1-3 weeks
Term
how long should someone with Grade II tear wait to return to activity
Definition
4-10 weeks
Term
how long should someone with Grade III tear wait to return to activity
Definition
8-10 weeks
Term
are there more medial or lateral instablities?
Definition
more medial instability injuries
Term
what are the 2 main lateral ligaments of the knee?
Definition
lateral collateral ligament and arcuate ligament
Term
what is the lateral collateral ligament's primary restraint
Definition
varus stress at 0 deg
Term
what is the LCL's secondary restraints
Definition
anterior displacement, rotation, hyperextension
Term
where is the popliteus tendon compared to the LCL
Definition
popliteus is under the LCL
Term
what is the functional interference of the LCL?
Definition
inability to turn quickly
Term
what is the primary restraint of the arcuate ligament
Definition
varus in flexion
Term
what are the secondary restraints of the arcuate ligament
Definition
varus at 0, hyper extension
Term
what type of stress will result in lateral instability of the knee
Definition
Varus force in weightbearing
Term
what ligaments are implicated in a positive varus test at 0 degrees
Definition
LCL, arcuate, ACL, PCL
Term
what ligaments are implicated in a positive varus test at about 30 degrees
Definition
LCL, arcuate, posterior-lateral capsule
Term
what other tests might be positive with lateral joint instability
Definition
pivot shift, lachman
Term
what is a mechanism of injury for a lateral instability caused in open chain
Definition
lateral force of the ankle
Term
what is another mechanism of lateral instability in closed chain other than varus force to the knee
Definition
as the person hits the ground, the thigh externally rotates and puts extra stress on outside of knee as foot goes into inversion
Term
could a grade III lateral joint instability require surgery
Definition
yes
Term
are lateral joint instabilities commonly injured with ACL, PCL
Definition
yes
Term
when might ACL injuries include LCL/arcuate
Definition
ACL rotational injuries
Term
what are the primary restraints of the ACL
Definition
anterior displacement, rotation (primarily IR), hyperextension
Term
what are the secondary restraints of the ACL
Definition
varus/valgus
Term
is the ACL inside or outside the synovial cavity
Definition
outside
Term
when is the ACL taut?
Definition
part of the ACL is taut throughout knee ROM
Term
what is the functional interference of the ACL
Definition
essential for higher level functions like running, cutting
Term
is there more strain on the ACL in tibial internal or external rotation
Definition
more strain in tibial IR
Term
why do you need to be sure the screw home mechanism works properly in patients after ACL reconstruction
Definition
in screw home mechanism, tibia rotates laterally, taking some stress off of ACL
Term
is the ACL inside or outside the joint
Definition
inside
Term
what are mechanisms of injury that cause straight anterior instability
Definition
PA force on tibia or AP force on femur in weightbearing with flexion; hyperextension
Term
what tests are often positive for straight anterior instabilities
Definition
Lachmans, anterior drawer, varus/valgus
Term
what test is often negative with straight anterior instability
Definition
pivot shift
Term
what structures are injured with straight anterior instability
Definition
ACL, MCL, POL, arcuate
Term
what are mechanisms of injury that cause anteromedial rotary instability
Definition
weightbearing valgus with tibial lateral rotation; valgus blow while cutting
Term
how do you know if you have an anteromedial rotary instability
Definition
when you pull the tibia toward you, you expect both tibial condyles to come toward you. If medial comes more htan latearl, that's anteromedial rotary instability.
Term
what structures are injured with anteromedial instability
Definition
MCL, ACL, POL, sometimes medial meniscus
Term
what is the unhappy triad
Definition
MCL, ACL, medial meniscus
Term
what else should be checked along with anteromedial rotary instability
Definition
posterolateral quadrant
Term
what tests are usually positive for anteromedial instabilities
Definition
Lachmans, slocum in 15 deg tibial ER, sometimes pivot shift, sometimes McMurry
Term
why does tibial lateral rotation harm the ACL when the knee is weightbearing in valugs
Definition
if we move the tibia laterally, it takes the ACL and wraps it around the inside of the lateral femoral condyle, increasing strain on it.
Term
describe anteromedial instabilities and ACL tears
Definition
If a person plants her foot and doesn't go into screwhome with tibial ER at full extension, the ACL is stressed. Then if the tibia Ers and the femur Irs, the ACL is wrapped around the lateral femoral condyle. Stresses the ACL.
Term
what are mechanisms for anterolateral rotary instabilities
Definition
noncontact deceleration that pulls tibia forward on planted foot; cutting toward same side, putting extended leg on ground,tibia goes into relative IR
Term
what structures are damaged in anterolateral instability
Definition
ACL, lateral capsule
Term
what tests are positive in anterolateral instabilities
Definition
slocum drawer IR, pivot shift, flexion rotation drawer
Term
are anterior instabilities usually caused by contact?
Definition
no
Term
how do stiff landings cause anterior instabilities?
Definition
knee is near extension and falling backward as you land. Quads take the tibia and yank it forward, popping ACL
Term
why are weaker quads more likely to tear ACL
Definition
less controlled
Term
are girls or boys more likely to have anterior instabilitie
Definition
girls
Term
why does a slightly flexed knee put ACL more at risk than fully extended knee
Definition
If knee is slightly flexed, it puts the knee out of screwhome. The Tibia rotates more medially, so ACL is in line so that if the tibia is pushed forward or if femur is stretched back, it is a direct force on the ligament.
Term
describe valgus collapse position of the knee
Definition
if my right foot comes forward and I plan tmy foot, flex my knee, get extra valgus, the tibia will relatively ER and the femur will relatively IR. An extra force across posterolateral to anteromedial will cause the tibia to ER. ACL wraps around lateral femoral condyle
Term
where do ACL replacements come from
Definition
allograft = cadaver, autograft = self, synthetic
Term
what is a primary ACL repair
Definition
taking the 2 ends of the ACL and sweing them back together. High failure rate because they're easy to tera
Term
is accelerated rehab good for ACL reconstruction?
Definition
yes
Term
describe accelerated rehab for ACL reconstruction
Definition
immediate weight bearing, full extension day 1. by 2 weeks: if flexion 100, guided exercise/strength. 4 weeks unlimited ADL. Light sports by 8 weeks
Term
compare return to light sports time for accelerated vs non-accelerated ACL rehab
Definition
8 weeks for accelerated, 6 months non-accelerated
Term
how can you reduce anterior knee pain following ACL reconstruction
Definition
get to full knee extension as quickly as possible. Return to screw home mechanism to protect graft
Term
at what point is the ACL graft weakest
Definition
6 weeks
Term
what is the general protection phse for the ACL
Definition
2-4 weeks
Term
when are ACL grafts strongest?
Definition
1-1.5 years after surgery. Still never as strong as original
Term
what to do to avoid future problems and avoid extra tension on ACL
Definition
return to screw home mechanism asap
Term
what closed chain exercises to avoid post surgery and why
Definition
squats beyond 60 degrees. Want to avoid anterior glide of the tibia created by the quads
Term
should you avoid all closed chain knee extension exercises? Why or why not?
Definition
need to do both open and closed chain quads exercises because the quads lag behind everything else.
Term
what open chain exercises should be avoided following ACL reconstruction
Definition
terminal extension, SAQs. From 15 deg short of extension, there is a 60% increase in quads force required to pull the knee into extension. Pulls too much on ACL
Term
what muscle should be emphasized to provide active stabilization of the knee following ACL reconstruction
Definition
hamstrings
Term
when would you need to slow the progressive resistive exercises for the hamstrins?
Definition
if the graft came from the hamstrings
Term
what are common problems following ACL reconstruction
Definition
graft failure, patellar tendonitis, anterior knee pain
Term
what is an uncommon poblem following ACL reconstruction
Definition
patellar fracture
Term
describe how a cybex can be used in ACL reconstruction rehabilitation
Definition
cybex can give posterior force to proximal tibia to keep from putting stress on ACL as you do TKEs. Can change levers to do concentric quads up and concentric hams down, but can't use the same levers to resist up and down.
Term
when can you return to cutting after acl reconstruction
Definition
6 months
Term
what are the primary restraints of the PCL
Definition
posterior tibial motion, hyper extension, rotation, anterior femoral motion
Term
what are the secondary restraints of the PCL
Definition
varus/valgus
Term
is the PCL inside or outside the synovial cavity
Definition
outside
Term
is the PCL tense in extension or flexion of the knee
Definition
extension
Term
what is the functional interference of the PCL
Definition
squat, descend stairs, run backward
Term
what is posterior tibial motion?
Definition
pushing tibia front to back
Term
where is the center of rotation of the knee and what does that mean?
Definition
resides in the PCL. PCL assists in locking the knee into screw home
Term
what are mechanisms of injury resulting in posterior instability
Definition
tibia forced posteriorly. Hyperextension. Hyperflexion
Term
when might a tibia be forced posteriorly
Definition
car crash, dashboard knocks tibia posteriorly
Term
give an example of a hyperextension injury resulting in posterior instability
Definition
gymnast lands in hyperextension and tears ACL and PCL
Term
give an example of hyperflexion injury causing posterior instability
Definition
drop down and sit on your heels
Term
what ligaments are implicated in a positive posterior drawer test
Definition
PCL, POL, arcuate
Term
what is a mechanism of injury for posterolateral rotary instability
Definition
varus force to knee in hyperextension
Term
what test would be positive with posterolateral rotary instability?
Definition
external rotation recurvatum test
Term
what ligaments are implicated with positive external rotation recurvatum test
Definition
arcuate, LCL, popliteal tendon
Term
with PCL reconstruction, what muscle do you want to train to assist the PCL
Definition
quads: assist the PCL to help shift tibia forward
Term
when to do surgical reconstruction of PCL.
Definition
rarely. Usually does well with conservative treatments. Reconstruct if gross instability present.
Term
is it better to do early or postoponed repairs on PCL
Definition
early
Term
what are signs and symptoms of ligament injuries
Definition
fast effusion, giving way, positive instability testing, may have tenderness at involved structures
Term
how to treat Grade I ligament injurie
Definition
modify activities, treat pain and swelling, return to activity
Term
how to treat grade II ligament injuries
Definition
protect to allow healing, friction massage, careful return to activity
Term
how to treat grade III ligament injuries
Definition
may require surgical intervention. Rehab for dynamic stability
Term
do MCL/LCL or ACL/PCL have better blood supply
Definition
MCL/LCL have better blood supply than ACL/PCL
Term
how are MCL/LCL usually treated
Definition
with immobilization
Term
how to protect ligament injuries
Definition
brace? Surgery? Stabilize to prevent further damage
Term
why control swelling?
Definition
prevent detriment
Term
when/why to add ROM
Definition
when it's safe to control size/quality of scar tissue and prevent adhesions
Term
when to add in strength following ligament injuries
Definition
when structures around the joint are stable. Start with isometrics then leg press, quads, hamstrings, calf raises. Then low grade weightbearing activities that allow activity
Term
how to improve proprioception following ligament instabilities
Definition
single leg stance
Term
how to determine what biomechanical corrections should be made with ligament instabilities
Definition
look at posture, see that they are using all muscles correctly
Term
what are mechanisms of meniscal injruy
Definition
squat to standing with valgus/tibial lateral rotation; insidious with long-term compression
Term
describe the squat to standing that tears meniscus
Definition
in full squat position as femoral condyles come down, they compress meniscal structures against the tibia. Medial meniscus is caught. As person stands up, puts more weight on that side, rotates and twists, it can tear.
Term
what are signs and symptoms of meniscal injuries
Definition
pop, catching/locking, effusion, giving way, anterior/medial joint line tenderness
Term
what are the 3 special tests for meniscal injury
Definition
mcmurry, apleys compression, bounce home
Term
what is the difference between catching and locking
Definition
catching is momentary, locking gets stuck
Term
what is the role of the meniscus
Definition
increases contact area, decreasing pressure and reducing risk of OA
Term
is medial or lateral meniscus more commonly injured
Definition
medial
Term
where is the blood supply of the meniscus
Definition
lateral in adults.
Term
as age increases, how does likelihood for meniscal injures change
Definition
increases. Repair and healing decreases. Stiffness increases, shocak absorption decreases
Term
is the meniscus aneural
Definition
mostly, yes. There are nerves in the outer portion. There is also less blood supply in the middle.
Term
how does the middle area of the meniscus get its nutrition?
Definition
from compression/movement of the joint
Term
what is the most common meniscal tear
Definition
bucket handle in the posterior horn of the medial meniscus
Term
what are options for meniscal surgeries
Definition
open, scope. Inside-out or outside-in.
Term
if you see a meniscal injury,what do you do
Definition
activity modification, resolve swelling, restore ROM/strength, MD referral?
Term
what to do immediately after meniscal repair
Definition
protect the repair. Control motion with brace locked at 0, slowly increase. Begin isometrics. Slowly increase motion with bike swinging back and forth
Term
what to do 4-8 weeks following meniscal repair
Definition
increase motion, increase WB, slow increase with passive resistive exercises and conditioning
Term
what to do >8 weeks after meniscal repair
Definition
progress all ROM, strengthening, functional activities while staying out of fully flexed positions.
Term
when to return to activities following meniscal repair
Definition
6 months
Supporting users have an ad free experience!