the knee Flashcards
what makes up the patellofemoral joint
distal femur and posterior patella
what is the honorable mention of th knee
proximal tibiofemoral joint
the tibiofemoral joint is joined anteriorly by the ____ ____
patellar groove
on the tibia there is a ____ degree posterior slop of the plateau
7-10
is the distal femur concave or convex
convex
genu valgum causes ___ forces on the laterla aspect of the tibiofemoral joint and ___ focrces on the medial aspect
compressive
tensile
(tensile on medial , compressive on lateral)
genu varum casues tensile forces in the ___ aspect of the tibiofemoral joint
lateral
compressive on medial and tensile on lateral
in genu valgum the weight bearing line passes ___ and for genu varum the weight bearing line passes ___
lateral
medial
what are the functions for the meniscus
• Improve congruence
• Transmit/distribute weightbearing loads (50-70%) • Reduce tibiofemoral friction
• Provide shock absorption
• Enhance joint stability
what shape is the medial and lateral meniscus
medial is C shaped
lateral is 4/5 of a circle
which ligament connects the menisci anteriorly
transverse
which meniscus is more restricted
medial
what firmly attaches medial mencius to the joint capsule
MCL
what attaches to the anterior horn of the medial meniscus
ACL
what attaches to the posteior horn of the meniscus
PCL
the medial meniscus is an attache sight for which mm
semimem
the anterior horn of the laterla mencius and ACL Share the ___ insertion site
tibial
which mencius attached to PCL thru meniscofemroal ligament
lateral
the lateral meniscus is an attached sit for which mm
popliteus
the horns are well vasucalized T./F
true
the bony congruence and ligaments tautness are maximal in full ___
extension (closed packed position)
the anterior border of the joint capsule of the knee consist of what four things
quad tendon
patella
patellar tendon
extensor mechanism
the synovial layer in the knee is extensive for ____ and ____
lubrication and nutrition
what 2 ligaments of the knee are intracapsular but extra synovial
ACL AND PCL
what are synovial plica
folds of synovial membrane
what is the thicket band in the medial reinaculum
medial patellofemoral ligament
varus stress on the knee causes ___ of tibia
valgus stresses on the knee casues ___ of the tibia.
add
abd
the MCL of the knee connects to the ___ femoral condyle to the ___ tibia
medial
proximal
the MCL is the primary restraint to excessive ___ and ___ tibia rotation
valgus
lateral
the MCL is ___ in hypertension but plays a key role in ___ as well
taut
flexion
what is the secondary role of the MCL
resist anterior translation of tibia on femur
the LCL attaches from the ___ femoral epicondyle to the ___ head
lateral
fibular
what MM does the LCL joint with
BF
what ligaments is Primary restraint for varus stress and limits excessive lateral rotation
LCL
the LCL also helps to prevent ______ rotators instability
posterolateral
the LCL is __- in full extension but also effective in ___
taut
flexion
the ACL extends ___ , ___ and ____
inferiorly, medially, and anteriorly
what Attaches to lateral and anterior aspect of medial intercondylar tibial spine
ACL
what is located on the Posteromedial aspect of lateral femoral condyle
ACL
how many bundles does the ACL have
2 (Anteromedial bundle (AMB) and posterolateral bundle (PLB))
the ACL is primary restraint against ___ translation of the tibia on femur
anterior
what bundle of the=he ACL becomes taut in extension and which becomes taut in > 15° of knee flexion
PLB
AMB
what is Also responsible for resisting hyperextension (PLB) and rotatory instability of the knee
ACL
when do most ACL injuries occur
when the knee is slightly flexion and in a valgus position combined with anterior tibial translation
what are Muscles that act to translate tibia anteriorly relative to the femur
quad and gastroc
what are Muscles that act to translate tibia posteriorly on the femur
hamstrings and soleus
Co-contraction of hamstrings and quadriceps allow the hamstrings to counter the ___ translation imposed by the ____
anterior
quadriceps
___ can resist anterior translation of tibia if foot is on the ground
Soleus
what is located on the Anterolateral aspect of medial femoral condyle to posterior tibial surface between posterior horns of two menisci
PCL
is the pcl or acl bigger
pcl
what band of the PCL is taut near full extension and which is taut at 80-90 of knee flexion
posterior medial bundle
ALB
the PCL Resists ___ tibial displacement
posterior
____ and quad shares role of PCL; ____ and gastroc increase posterior shear
Popliteus
hamstring
which ligament is a tendinous expansion of semimembranosus
oblique popliteal lig
which lig of the posterior capsule is taut in EXT; resists varus/valgus
posteior oblique lig
which ligaments of the post capsule taut in EXT; resist varus/valgus and rotation
arcuate lig
what is PLRI
interruption/damage to LCL, popliteus, arcuate and popliteofibular ligament
what is Extension of fascia covering the tensor fascia latae (TFL) and gluteus maximus muscles
ITB
where is the primary attachenment of ITB
Gerdy’s tubercle + distal femur/lateral border of patella
the ITB Increases ____ stability
lateral
the ITB is Traditionally believed to “____” over lateral femoral condyle during
knee FLX/EXT
roll
during closed chain flexion of the knee joint the femur rolls ____ and glides ___
posteriorly
anteriorly
for closed chain extension at the knee joint the femur rolls____ and glides ____
anteriorly
posteriorly
during open chain flexion at the knee joint the tibia rolls and glides ____
posteriorly
during open chain extension at the knee joint the tibia rolls and glides ____
anteriorly
when the femur moves on the knee it is ___ on ____
convex femur on concave knee
when the tibia moves on the knee during open chain it is ___ on ____
concave on convex
how much knee flex does walking require
60-70°
how much knee flexion does stairs need
80°
how much knee flexion do u need to sit to stand
> 90°
knee extension may be limited to fixed ankle ___ or tightness of___
DF
PF
tightness of PF may also present with genu ___ at the knee in standing
recurvatum
in probe knee flexion may be limited by passive insufficiency of ___ ____
rectus femoris
close chain knee flexion casues which ligament to become taut
closed chain knee extension causes which ligament to become taut
ACL
PCL
menisci shape and deformation help steer roll and slide, there will be a ___ deformation with flexion and a ____ deformation with extension.
posteior
anterior
there is More motion of the ____ tibia/femur than ____
lateral
medial
medial rotation (tibia on femur)→ deformation of MED meniscus ____ and LAT meniscus ____
posteriorly
anteriorly
in 90° of flexion at the knee how much IR and ER is there
IR - 15
ER- 20
what is loose and closed packed position of the knee
loose - 30° of knee flexion
closed- full extension
Terminal knee extension is accompanied by ____ rotation (open chain) of the tibia
lateral
Flexion from full extension requires unlocking – ___ rotation of tibia (open chain) or ____ rotation of femur (closed chain)
medial
lateral
Flexion from full extension requires unlocking – medial rotation of tibia (open chain) or lateral rotation of femur (closed chain)… what mm does this
popliteus
___ and _____ can assist knee EXT in weightbearing
Soleus
Glute Max
In full EXT, line of gravity passes ____ to knee axis creating ____ moment
anterior
extension
In squat, gravity pulls into knee FLX and ___ eccentrically control flexion
quads
Quads are typically twice as strong as ____
hamstrings
in Open chain (NWB) quads must generate more torque (and more force) as the knee approaches
full ____q
extension
in Closed chain (WB) the quads generate more force as the knee _____ to control the increasing
moment arm (and torque)
flexes
Open Chain: MA of resistance increases as knee extends, greater quad force is required as extension progresses; produces ____ tibial shear especially at 10-20 deg
anterior
Closed Chain: MA of resistance is minimal in full extension and increases with squat; squats and leg press result in ____ tibial shear especially at 85-105 deg
posterior
what 5 things limit anterior tibial translation
ACL,
ITB,
hamstrings,
soleus,
Glute Max
what 5 things limit posterior tibial translation
PCL
MFL
quads
pop
gastroc
the MCL, ACL, PCL, arcuate, POL, medial muscles, pes anserinus muscles all limit kne ___
valgus
the LCL, ITB, ACL, PCL, arcuate, POL, lateral muscles all limit ____
varus
ACL, PCL, PM Capsule, MFL, BF all limit ___ rotation of the tibia
medial
PL Capsule, MCL, LCL, medial muscle all limits ___ rotation of the tibia
lateral
what is the patella attached to
quad and patellar tendon
is the patella congruent or incongruent
incon
in an extended knee the patella sits on the ___ ___
femorla sulucs
Patella translates and rotates on ____ condyles
femoral
when the knee flexion there is an ____ glide on the patella and ___ slide during extension
inferior
superior
are the compression forces of the patellofemoral joint larger in extension or flexion
flexion
when is open/loose pack for the patello femoral joint
when the knee joint is in closed packed
Physiologic valgus of femur/tibia causes patella to be pulled slightly ___ by quad and patellar tendon forces
laterally
what are the longitudinal stabilizes of the patellofemoral joint
Patellar tendon inferior and quad tendon superior
at the patellofemoral shaft if there Excessive extension (genu recurvatum) will increase the potential for frontal plane ___
instability
the Superficial extensor retinaculum from vastus medialis and lateralis are ___ stabilizers of the patellofemorall joint
transverse
• Weak VMO
• Tight ITB/TFL
• Genu Valgum
• Femoral anteversion
• Lateral tibial torsion
• Foot pronation
• Stretched medial structures
all of these are from ___ patellar forces
lateral
an increased Q angle will present with genu ___
valgum
what is the normal Q angle
10-15
May need to avoid last 30 deg of extension in non-weight bearing exercises for what type of pain
patellofemoral pain
Plica irritation is from what
sitting, stairs, extension exercise
Meniscal injuries from what
rotation on a fixed tibia; microtrauma
Ligament tears from what
excessive high forces or low level repetitive stresses
Bone and cartilage damage:
high load or fall
Bursa and tendon from what
direct blow or repetition
what is chondromalacia
cartilage changes
