The Knee: general exam - Lecture 1 Flashcards
What is the terrible triad for the knee?
MCL
Medial meniscus
ACL
(This happens w/ excessive valgus)
A pt was running and foot got stuck and they came to a quick stop. They said they felt their knee bend backwards. What kind of injury is this most likely? What is likely to be messed up?
“Felt like knee went backwards”
Hyperextension
ACL (often when the ACL is affected the MCL / medial meniscus are also affected)
NOTE: w/ hyper extension its the femur sliding posterior and the tibia going anterior - which is why its the ACL thats affected
What position is the ACL most taut?
Extension (hints why hyperextension is where we get ACL ruptures)
Extension = femur sliding posterior which means that the tibia is anterior
ACL origin and insertion
Origin: Medial wall of lateral femoral condyle
Insertion: Middle of the anterior intercondylar area of the tibia
KNOW: The knee joint itself isnt that stable (not a deep joint) - however there a lots of ligaments to help w/ that stability
If someone was hit on the lateral knee pushing in what kind of injury would they have?
Valgus style injury (knee pushed in)
Ipsilaterl cutting causes varus or valgus?
Varus
Cutting to the right causes right varus
Whats a more common injury at the knee, a varus or valgus force?
Valgus
Theres an extreme valgus force at the knee. What has likely happened?
The terrible triad happens w/ excessive valgus force
What 3 things happen w/ varus force? (injuries)
LCL
posterolatearl capsule
PCL
NOTE: normally this is from some kind of cutting (you do it to yourself often)
What kind of activity results in a PCL injury
Hyperflexion
Dashboard injuries are normally waht kind of injuries
* Flexion or extension?
* What ligament gets messed up?
Flexion style injury
PCL is damaged
KNOW: w/ PCL injuries the tibia is moving posterior (femur anterior) which is a flexed position causing that ligament to become taut and rupture
**KNOW:
**ACL injury
* Anterior moving tibia
* Posterior moving femur
PCL injury
* Posterior moving tibia
* Anteior moving femur
What is the most common position for a PCL rupture? (2)
Flexion w/ posterior translation
What kind of injury will this person most likely have?
PCL
What kind of injury is this person likely to have? Explain MOI
PCL
They are in a flexed position and when their knee hits the dash board it will posteriorly translate that tibia causing that PCL to become taut and reupture
KNOW: When the knee flexes the PCL becomes taut because the femur actually shifts forward
https://www.youtube.com/shorts/yQfHCgndVTM
Whats a grade 3 ligament sprain?
Rupture
What two things can be damaged w/ flexion of the knee?
PCL (duh)
Medial meniscus
What is damaged w/ twisting? (3)
* KNOW: twisting is done in a closed chain environment w/ that toe planted on the ground
ACL
PCL
Meniscus
NOTE: ACL/PCL resist rotatory motions
What muscle could potentially rupture w/ knee hyperflexion?
Quads
KNOW: If theres lots of swelling around the knee I’m thinking more extracapsular (i.e., some kind of muscular rupture). However, if theres not much swelling I’m thinking more intracapsular (think ligaments because most of the ligaments are intracapsular around the knee)
KNOW: 3 kinds of knee injuries
* Accceleration style
* Deceleration style
* Constant speed w/ cutting
Acceleration style knee injuries normally damage what part?
Meniscus
Deleration style injuries in the knee normally injure what? Explain MOI
Cruciate ligaments (ACL/PCL)
As I stop moving on that foot my body weight is going to keep moving forward
* that causes both ACL and PCL to be pulled taut and rupture
* tibia moving posterior (because femur is moving forward)
Constant speed with cutting style injuries cause what to be messed up? Explain MOI
This is a quick stop and turn motion or twisting. This is tibial rotation.
ACL
Pes anserine attaches what 3 muscles
1) Sartours
2) Gracilis
3) Semitendinosis
SGTFOS (sargent FOS)
* Sartours
* Gracilis
* semiTendinosis
* Femoral obturator sciatic innervates
If pt is having anterior knee issues what 5 things am I thinking it could be
1) Patellofemoral pathology
2) Bursa
3) Fat pad
4) Tendinitis/osis
5) Osgood-Schlatter’s disease (younger)
This is a lump more infrapaterlla (tibial tubersoity area)
If pt is having medial knee issue what 5 pathologies am I thinking?
1) MCL sprain
2) Medial meniscus tear
3) Pes anserine bursitits (bursa here)
4) Plica syndrome (you have synovial folds at birth that eventially turn into joint capsule. in some people these little folds invaginate on themselves and become true little folds, and those folds can get caught and stuck in the joint w/ movement)
5) Medial articular cartilage lesion
If pt has vauge aching pain on the back and no MOI what should I look at?
The spine / back
* L3/L4/L1/L2
* Femoral n
Always keep these thoughts in the back of mind w/ vauge pain w/ no MOI
Vauge pain to the medial knee is most likely what n roots? you’re also checking what peripheral nerves
L3/L4
Also check obturatory n / saphenous
what peripheral n innervates posterior knee?
Sciatic n
Pt is having lateral knee pain. What 4 diagnosis am I thinking?
1) LCL sprain
2) Lateral meniscal tear
3) IT band syndrome
4) Lateral articular cartilage injury (think like OA)
KNOW: Medial meniscus is MUCHHHH more likely to have issues than lateral
What 4 patholigies am I thinking if I have a posterior knee pathology?
1) popliteral cyst
2) PCL
3) Distal hamstring injury
4) Proximal gastroc injury
If pt has knee pain whenever they are moving their foot / ankle what am I thinking?
SUPERIOR (proximal) tibiofibular joint (because that rotatory movement distally is going to cause those superior unstable structures to move and cause pain)
If theres aching pain in the knee what kind of pathology am I thinking
More degenerative
* Think OA
Sharp pain / catching in knee its typically what kind of problem?
Mechanical pain (think internal stabilizing components)
* Meniscus or one of our stabilizing ligaments (MCL/LCL/ACL/PCL) (we have special tests to help us differinatite)
* KNOW: medial meniscus more likely than lateral
Pain in knee after activity what pathology am I thinking?
Inflammation
If theres swelling at the knee but no trauma what am I thinking? (3)
Infection
Gout
RA
Knee giving out due to instability. What are 3 kinds of instability that can cause this
Active stabilizer issue (muscles)
Passive stabilizer issue (ligaments)
Neural stabilizer issue (properioceptors sending bad information back to SC)
KNOW: Meniscus can make the knee feel like its giving out
* Subluxation of the knee can also do this
* Osteochondritits dessicans can do this
* Patellofemoral syndrome
What are the 3 main things that cause the knee to give out
Patellofemoral syndrome (under knee cap is damaged)
patellar subluxation
Instability (active vs passive vs neuro)
What are 2 things that cause locking of the knee?
Loose bodies
Meniscus issue (can tear off and cause loose bodies)
Grating / grinding of the knee is due to
degeneration (think OA)
KNOW: theres a decent link between hip OA and knee OA. This is due to kinematics of the person (poor movement) causing both to degenerate or one causing the other to degenerate
* Often pts w/ hip OA also have knee OA
KNOW: Swelling w/ activity is often linked to instbaility. AKA the knee isnt really moving the way it should which causes that inflammation (internal trauma is occuring)
If theres swelling w/ pivoting or twisting what 2 things am I thinking
1) meniscus issue
2) Instability at the tibiofemoral joint
If theres swelling around either end of the quadrceps tending and a stiff kneecap what am I thinking?
patellofemoral dysfunction (says recurrent w/ climbing stairs - so I think it comes on when climbing stairs)
When does synovial fluid swelling happen?
8-24 hours after injury (this is where surgery no longer occurs [skiers])
What is hemoarthrosis?
Bleeding within the joint
How long does it take hemarthrosis to start in the joint after injury?
Right after (immediate)
If pt rerports swelling that started 8-24 hours after the injury what am I thinking?
Synovial fluid swelling (starts 8-24 hours after intital injury)
pt reports swelling in joint that started immediately after injury. What am I thinking?
Hemarthrosis (can take up to 2 hours but often happens immediately after joint injury)
KNOW: Knee outcome measures
* LEFS (most common) - best for keeping it specific to the knee
* Knee injury and osteoarthritis outcome score (KOOS) - would pick this over WOMAC because its specific to the knee
* Western Ontario and MCMaster Universities Osteoarthritis Index (WOMAC)
* Patient Specific Functional Scale (PSFS) - can be used for pretty much anything
KNOW: Red flags in the knee/lower leg: = refferal out (no right answer between if you finish your eval or immediately send out - if they’re in a crisis obvisouly send out but its a case by case issue and will vary)
* Fractures (ottawa Knee Rules, Pittsburgh decision rule, patellar pubic percussion test)
* Peripheral artery disease (usually worsened in a dependent position - sitting causes more pain in limb and I’m seeing significant redness pooling in LE / skin discoloration - looking for brown / purpilish discoloration changes of the skin or trophic changes [skin changes = hair loss in that area - dryer patch / shinny skin / taut skin etc…)
* Deep vein thrombosis (think post surgery / immobilization / significant trauma to LE)
* Compartment syndrome - most common is anterior compartment syndrome
* Septic arthritis (infection of the joint)
* Cellulitits
Common red flags
* Fever/chillds/night sweats
* Unremitting night pain
* Bilateral symptoms in a non-trumatic event (could be some kind of sepsis or even a new bout of RA)
* Prolonged corticosteriod use (if ever on test proably the answer)
* Smoking (if ever on test probs the answer)
Common Yellow Flags: Not immediate refferal out - generally psychosocial in nature
* Fear of movement
* Somatization - body creating pain when theres no real injury there
* Negative coping skills
* Depression
* Long duration of complaints
KNOW: If you have a non traumatic injury distal to gluteal fold you raelly need to do a neuro screen and clear the lumbar spine
How do you clear the lumbar spine?
AROM + OP
Can also do CPAs / UPAs
What nerve roots refer to the knee? (anterior and posterior)
L3/L4 Anterior
S1/2 Posterior
KNOW: I would check lumbar spine –> Hip –> ankle for knee dull achy pain w/o a trumatic MOI
What is the open packed position for the knee joint?
15-25 degrees
allows for more swelling
KNOW: When looking head on at the knee the patella should be facing forward w/o tilt
What is patella alta?
Higher riding patella
Think A for above
What is patella Baja?
Lower riding patella
Think B for below
Notice where normal is (weird)
What is this?
Patella alta
What is this?
Patella Baja
KNOW: The whole purpose of the patella is to essentailly create a longer lever arm for the quads. So when the patella is deviated from the norm that lever will be shorted and we won’t have as much force production from the quads
* So we will notice decrease m output (or the muscle might even be completely inhibitied)
What is a squinting patella?
Medially tilted patella
Think when you squint you can only see out of the middle of your eyes
What is grasshopper eyes patella?
Lateral tilted patella
What is this?
Squinting patella
KNOW: If its bilateral they were probs born w/ it
Is patella more likely to be pulled centrally or laterally (central tracking vs lateral tracking)
More likely to be pulled laterally (latearl tracking of the patella)
KNOW: Lots of our latearl structures are very taut - so they will likely pull the patella to them causing it to laterally track
What kind of strenghtening would we recommend for someone w/ laterally tracking patella? Why?
If its laterally tracking its being pulled latearlly by those taut lateral structures. More than likely this is because of weak medial structures. We should strengthen adductors / quads (originally they would just strengthen vastus medialis - now we just strenghtne quads as a whole because its alsmost impossible to target singular quad muscles)
What is genu recurvatum?
Hyper extension of the knee
What kind of tears are related to genu recurvatum?
PCL tears
KNOW: THIS IS NOT THE CAUSE OF PCL TEARS - ITS JUST HOW SOMEONE W/ A PCL TEAR WOULD STAND AFTER THE TEAR
What position of the knee gives us the most stability possible?
Full extension because thats the knees close packed position
What typically causes an inferior (or sometimes superior) tilt of the patella?
Fat pad irritation
Fat pad irritation can create what in the knee? (what sign)
Camel sign
In 20-30 degrees of knee flexion it will show a second hump.
The patella is also pulled superior (alta) and the fat pad underneath it is irritated and creates that hump sign
KNOW: There is a fat pad just inferior and deep to the patella
Why would a knee pt be resting w/ a towel roll underneath their knee?
Because that puts them into that 20-30 degrees of knee flexion (which is the open packed position for the knee)
Open packed position for knee
25 degrees of flexion
What is this?
Popliteal cyst
Look at other leg to know its the posterior aspect of leg (because it looks like a kneecap)
or can look at popliteal crease
delta for leg length discrepency?
1.5CM
ASIS –> medial mallelous
What two motions does the ACL primarily restrain?
What about the two that it secondarily restrains?
(OPEN CHAIN)
Primary: Tibial anterior translation and medial rotation (notice PCL also stops medial rotation)
Seconday: restraint to varus / valgus rotation (same as PCL)
What two motions does the PCL primarily restrain?
What about the two that it secondarily restrains?
(OPEN CHAIN)
Primary restraint: keeps tibia from posterior translation and medial rotation (notice ACL also stops medial rotation)
Secondary: restrains varus / valgus rotation (same as ACL)
Whats a thicker ligament ACL or PCL?
PCL
KNOW: PCL also has twice the tensile strength as ACL (makes sense, its twice as thick)
What position puts ACL in the most taut position?
Hyper extension (hits why it ruptures in this position)
What two motions does the MCL primarily restrain?
What about the two that it secondarily restrains?
(OPEN CHAIN)
Praimry: restrains valgus and external rotation of the tibia
Secondary: restrains anterior/posterior translation of tibia on femur
What two motions does the LCL primarily restrain?
What about the two that it secondarily restrains?
(OPEN CHAIN)
Primary: Restrains varus and extneral rotation (both LCL and MCL limit this external rotation)
Secondary: stops anterior / posterior translation of tibia on femur (same as MCL)
KNOW: Tibia shifting posterior = sag sign
Whats a stronger ligament ACL or PCL
PCL
Which tears are more rare ACL or PCL
PCL are more rare (stronger ligament)
Whats more rare LCL or MCL injuries?
LCL because varus style injuries are much more rare than valgus and LCL checks varus
How much hyperextension at the knee can women have?
15 degrees hyperextension is normal
What is an extensor lag?
When the person has quad weakness and cannot fully extend their leg
* their upper leg can hold the straight leg raise but their lower cant because of quad weakness (cant get terminal knee extension)
* Common term used for quad weakness during active SLR = extensor lag
In open chain _ rotation of the tibia on the femur during the last _ degrees of knee extension is known as screw home mechanism
External rotation
5-30 degrees
KNOW: We need screw home mechanism to reach terminal knee extension (which is our close packed position) - more stable
* while you dont absolutely need that 120 degrees of knee flexion - getting to 0 degrees of knee extension is super important because of being in that full exntesion during heel strike and not having your knee bucle
Medial femoral condyle is longer than lateral
* so the tibial platue is also bigger on the medial side
* So we have some wiggle room on the medial side so we add in that extra rotary motion to get it to the end
* That rotation gets us terminal knee extension for screw home mechanism
Which ligaments are taut in that scre home position?
Cruciate ligaments (think hyperextension for ACL, I dont fully understand PCL)
What 4 things can affect the screw home mechanism?
* Ligament
* Muscle
* Ligament 2
* anatomical
1) Meniscus - if you have a miniscus issue than the medial femoral condyle won’t have room for that rotary component
2) Quad strength: lateral portion of quads pulls to create that rotary movement
3) Cruciate ligaments health (they are both pulled taut, so if theres an issue w/ them they wont want to be pulled taut and won’t want to go into that screw home position)
4) Bony abnormalities (think the actual condyles of the femur being shorter or some boney abnormality)
Explain whats happen for the screw home mechnism in an open chain position?
What muscle is responsible for the unlock of this position
During the last 5-30 degrees of extension you will have external rotation of the tibia on the femur. This creates the lock position
Popliteus (think popping a lid off)
Explain the screw home mechanism in a closed kinetic chain
What is responsible for unlocking?
The difference here is that the femur is rotating on the tibia
Femur internally rotates on tibia during the last 5-30 degrees of extension to lock into closed pack position
Unlocking is done via hip (femoral) external rotation
* So thinking more glute max / PGOGOQ
What two movements do we want to train for a screwhome mechanism issue
What glide would we do to help w/ this?
Tibial rotation / knee exntesion
Would do anterior glide (anterior roll / slide when going into extension) (concave on convex)
What is the capsular pattern of restriction for the knee
Flexion more resitricted than extension
What is the close packed position for the knee?
Full extension
KNOW: When theres knee issues muscles that tend to be tight are:
* Adductors, Iliopsoas, Piriformis, TFL, Rec Fem, hamstrings
What special test would we do to see TFL tightness?
Modified ober > Ober
What special test would we do to test for tight hip flexors
Thromas test (lets us differeintaite rec fem)
What special test would we do to test for tight hamstrings?
SLR / 90:90
Anterior drawer tests?
ACL
Posterior drawer = PCL
Lachman test tests for
ACL
Posterior sag tests for
PCL
Jerk test tests for
ACL
Lateral Pivot Shift Maneuver tests for
ACL
Apleys test tests for
meniscus (mostly)
McMurray test tests for
meniscus
Plica “stutter” test tests for
Plica
Brush test tests for
Edema
Patellar tap test tests for
patellar infra fat pad dysfunction
Noble compression test tests for
IT band along gerdys tubercle
Thessaly Test tests for
Meniscus (more functional upright test)
Ege’s Test tests for
Meniscus (more functional upright test)
Meniscal injury (Lower et al) test item cluster
How many do you need
Rules it in
1) History of joint locking
2) Joint line tenderness
3) Positive McMurray test (special test for meniscus)
4) Pain w/ flexion OP
5) Pain w/ extension OP
Need 5/5
MCL Injury test item cluster (Kastelein et al)
Rules it in
1) History of external force or rotational trauma (trauma of ACL/PCL/MCL/LCL)
2) Pain w/ valgus stress @ 30 degrees
3) Laxity w/ valgus stress @ 30 degrees (so need to test side to side)
Need 3/3
Knee OA test item cluster (Cibere et al)
How many do you need?
Most important ones?
Rules in
- Age > 50
- Stiffness > 30 min
- Crepitus
- Boney tenderness (can palpate easily)
- Boney Enlargement (Wolfs law = repetitive stress over and over making this happen)
- No palpable warmth
3/6
Top 3 are most common - so most important
So someone w/ knee OA sometimes responds well to Hip mobilization because if they have knee OA they are likely to have hip OA (remember OA does well w/ mobilization because its intracapsular)
Knee OA responsders to Hip mobilization clinical prediction rule (Currier et, al)?
How many do they need?
Why would a hip mobilization help the knee (2)
Hip or groin pain
Anterior thigh pain
Passive knee flexion < 122 degrees
Passive hip IR < 17 degrees
Pain w/ hip distraction
2/5 needed
Helps because:
1) regional interdepence
2) If I distract the hip I’m also distracting the knee
During stance phase how much knee flexion do we need
~20
How much knee flexion do we need during swing phase?
~70
How much knee flexion do you need to squat to tie shoe or put on a sock? - or even gardening
120 (heel to butt)
How much flexion do we need to sit on chair / toilet (knee flexion)
90
How much flexion at the knee do we need to CLIMB stairs
80
Dermatomes
Myotomes
Pittsburgh Decision Rule
Used to see if you need a radiograph of the knee
Dutton differintial diagnosis - knee diagnosis
Dutton differential diagnosis - knee diagnosis