Lower Quarter 1 (Hip and Knee-Tibiofemoral) Flashcards
what makes up the coxofemoral joint/
acetabulum of the pelvis
femoral head
what type of join is the coxofemoral joint?
ball-and-socket joint
how many degrees of freedom does the coxofemoral joint have/
three
Where is the acetabulum located in terms of the innominate?
on the lateral aspect
what are the faces of the acetabulum?
lateral
inferior
anterior
what are the three bones that contribute to the surface of the acetabulum?
ilium-2/5th (upper)
ischium-2/5th (posterior)
pubis-1/5th (front)
What is the innominate?
half the pelvis
What does the acetabulum do/
accepts the head of the humerus.
What is the fossa of the acetabulum?
the deepest portion of the acetabulum
what is the lunate surface of the acetabulum?
horseshoe-shaped articular cartilage
What is the labrum of the acetabulum?
wedge-shaped fibrocartilage that rings the acetabulum
What does the labrum do in the acetabulum?
deepens the socket
helps to maintain contact with the head of the femor.
What is part of the head of the femur?
fovea
articulating surface
what is part of the neck of the femor?
trochanters (greater and lesser)
What are the faces of the head of the femur?
medial
superior
anterior
Which face does both the femur and acetabulum have?
anterior face
what is the angle of inclination of the femur?
Frontal plane angle
Angle between an axis through the femoral head/neck and a longitudinal axis through the shaft
What are the different angle changes of the femur throughout life?
at birth-150 degrees
in adult-125 degrees
elderly- 120 degrees
What are some abnormalities of the angle of inclination of the femur?
coxa vara- decrease in the angle (towards 90) femur goes inward, angle goes medially, adduction
coxa valga-increase in the angle (towards 180) opening up the angle
femur goes outward, angle goes internally, abduction
What is the angle of torsion?
it’s in the transverse plane
it’s the angle between an axis through the femoral head/neck and an axis through the femoral condyles
How does the angle of torsion change throughout life?
at birth-40 degrees
adult-10-15 degrees-internal rotation
what is the normal angle of torsion called?
anteversion
What are some abnormalities of the angle of torsion?
Excessive anteversion-increase in the angle
results in lower extremity internal rotation
Retroversion-goes more towards zero point or a decrease in the angle
results in lower extremity external rotation
What are some non-osseous structures?
joint capsule
ligamentum teres
What does the joint capsule do?
covers femoral head and neck
is the femoral neck intracapsular or extracapsular?
intracapsular
are the trochanters intracapsular or extracapsular?
extracapsular
where is the joint capsule of the hip the thickest?
anteriorly
where does the ligamentum teres go between/
acetabulum
to fovea
what is an important aspect of the ligamentum teres?
it’s intra-articular but extrasynovial
Is ligamentum teres a stabilizer?
No
what does ligamentum teres do?
provides secondary source of blood for the femoral head/neck
What are the stabilizing ligaments of the hip joint?
iliofemoral ligament
pubofemoral ligament
ischiofemoral ligament
where is the iliofemoral ligament located
anterior
what is a defining aspect of the iliofemoral ligament?
it looks like a “y”
what is the strongest ligament of the hip?
the superior band of the iliofemoral ligament
where is the pubofemoral ligament located?
anterior
What is a defining aspect of the pubofemoral ligament?
together with iliofemoral ligament it forms a “Z” on the capsule
where is the ischiofemoral ligament located/
posterior
What does extension of the hip do to the ligaments
winds the ligaments up
what does flexion of the hip do to the ligaments?
unwinds the ligaments
What position is the femur in while standing neutral?
anterior head of femur is exposed
where is the greatest joint congruency of the hip joint?
flexion
abduction
external rotation
when is the hip the most stable?
in a closed pack position because of the ligaments
What is the closed pack position of the hip?
extension
slight abduction
internal rotation
what are the flexors of the hip?
iliopsoas
rectus femoris
tensor fascia lata
sartorius
what are the extensors of the hip?
gluteus maximus
hamstrings
what are the adductors of the hip?
pectineus gracillis adductor magnus adductor brevis adductor longus
What are the abductors of the hip/
Gluteus medius
gluteus minimus
what are the external rotators of the hip?
obturator internus obturator externus gemellus superior gemellus inferior quadratus femoris piriformis-when hip is below 60 degrees gluteus maximus
what are internal rotators/
gluteus minimus
gluteus medius-ant. fibers
TFL
piriformis-when hip above 60 degrees
Where does the piriformis attach?
to the summit of the greater trochanter
In hip extension, what type of moment arm does the piriformis have?
a long moment arm
In hip flexion, what type of moment arm does the piriformis have?
a short moment arm
when the piriformis has a short moment arm what action does it perform?
internal rotation
when the piriformis has a long moment arm what action does it perform?
external rotation
What are the motions of the hip complex
flexion/extension (sagittal plane and coronal (M/L axis)
Abduction/adduction (frontal plane, A/P axis)
internal/external rotation (transverse plane, vertical axis)
What are the motions of the pelvis?
anterior pelvic tilt posterior pelvic tilt hip hiking pelvic drop forward rotation backward rotation
What is anterior pelvic tilt?
ASIS moves anterior and inferior
What is posterior pelvic tilt?
ASIS moves posterior and superior
What is hip hiking?
elevation of the contralateral iliac crest
What is pelvic drop?
depression of the contralateral iliac crest
what is forward rotation of the pelvis?
anterior rotation of the contralateral innominate
What is backward rotation of the pelvis?
posterior rotation of the contralateral innominate
What is the principle of the length tension relationship?
a two joint muscle is more able to act across one of the joints when it has been stretched across the other joint.
When is the rectus femoris most effective
As a hip flexor when the knee is flexed
As a knee extensor if the hip is extended
When does the rectus femoris have active insufficiency?
if the knee is extended when trying to flex the hip
when are the hamstrings most effective?
As a hip extensor when the knee is extended
As a knee flexor when the hip is flexed
What are the joints of the knee?
tibiofemoral joint
patellofemoral joint
What type of joint is the tibiofemoral joint?
a double condyloid joint
how many degrees of freedom in the tibiofemoral joint/
two degrees
what is the closed-packed position of the tibiofemoral joint?
extension with external rotation (of tibia)
what is the open-packed position of the tibiofemoral joint?
25 degrees of flexion-allows for the most volume
Is the patellofemoral joint considered a real joint?
no
where is the sesamoid bone located in the patellofemoral joint?
in the quadriceps tendon
what are the bony structures on the distal femur?
lateral and medial epicondyles
adductor tubercle
what are the bony structures located on the proximal tibia?
tibial plateaus
gerdy’s tubercle-IT band inserts here
tibial tubercle-Quads insert here
What are the bony structures of the proximal fibula?
head-biceps femoris inserts here
what are the bony structures of the patella?
base-on top
apex-on bottom
medial border
lateral border
What are the three facets of the patella?
lateral facet
medial facet
odd facet-located medial to medial facet
What are the non-osseous structures of the knee joint?
joint capsule synovial lining plicae bursae menisci
Is the joint capsule of the knee thick or thin?
Thin
What is the joint capsule of the knee reinforced by?
anteriorly-patella, quad tendon and patellar ligament
posteriorly-muscle, popliteal and arcuate ligament
medially-medial collateral ligament
laterally-lateral collateral ligament
what is the most extensive and complex aspect of the body?
the synovial lining of the knee
Where does the synovial lining adhere?
to the inner wall of the capsule except posteriorly where it follow the inercondylar notch
to the ACL and PCL
What are the ACL and PCL?
intracapsular, but extrasynovial-they are within the capsule, but not within the capsule synovial
What are plicae?
Folds or pleats in the synovial tissue-crunchy and cause pain
In what percent of the population do plicae exist?
20-70% of the population
Where are plicae usually located?
infrapatella
suprapatella
medial
What are bursae?
flat sacs of synovial membrane containing fluid
How many bursae in the knee?
as many as 14
Where are bursae formed?
in inter-tissue junctions that are subject to high friction during movement
What are menisci?
assymetrical fibrocartilaginous discs
What do menisci do/
deepens articular surfaces
smooths synovial surface to 200x smoother than ice
provides symmetry to the TF joint
acts as a shock absorber
What does the lateral meniscus look like/
a “d”
what does the medial meniscus look like?
a “c”
How does the menisci move/
must move with the tibia during flexion and extension
menisci move as people move, if they don’t they tear
flexion-pulls posteriorly
extension-shifts anteriorly
what prevents impingement of the menisci?
muscular attachments
what are the ligaments of the knee?
medial collateral ligament
lateral collateral ligament
anterior cruciate ligament
posterior cruciate ligament
What does the medial collateral ligament look like?
broad and flat, slops anteriorly
where does the medial collateral ligament attach?
to the medial condyle of femur and medial aspect of proximal tibia
some fibers attach to medial capsule and medial meniscus
what does the medial collateral ligament resist?
valgus stress
checks external rotation of the tibia
when is the medial collateral ligament most taunt?
in extension
what does the lateral collateral ligament look like?
strong cord
where does the lateral collateral ligament attach?
to lateral condyle of femur and head of fibula
what does the lateral collateral ligament resist?
varus stress
checks external rotation
When is the lateral collateral ligament most taunt?
in extension
Where does the anterior cruciate ligament run to?
from anterior tibia to the medial side of the lateral femoral condyle
what does the anterior cruciate ligament resist?
anterior tibial or posterior femoral displacement
resists extension- prevents hyperextension
checks rotation
What does the anterior cruciate ligament assist in
screw home mechanism- it gets taunt as you go into extension and gives a little twist.
where does the posterior cruciate ligament run from and to
from the posterior tibia to the lateral side of the medial femoral condyle
Compared to the ACL, what does the PCL look like?
shorter and more oblique compared to ACL
what does the PCL resist?
posterior tibial or anterior femoral displacement
resists flexion
checks rotation
Where does the PCL attach?
to the lateral meniscus via the posterior meniscofemoral ligament
What is the patellar tendon?
infrapatellar
attaches patella to tibial tuberosity
what is the quadriceps tendon?
suprapatellar
attaches quadriceps to the patella
what is the iliotibial band and the lateral retinaculum?
fibrous bands of connective tissue that support the lateral knee joint
Where do the iliotibial band and the lateral retinaculum attach?
on the patella
What can the iliotibial and lateral retinaculum cause?
abnormal alignment of the patella due to excessive lateral pulling on the patella
what are the prime flexors of the knee?
hamstring (semimembranosus, semitendinosus, biceps femoris)
gracilis
sartorius
What are the prime extensors of the knee?
quadriceps (vastus medialis, vastus lateralis, vastus intermedius)
rectus femoris
what are the internal rotators of the knee?
semitendinosus semimembranosus popliteus gracilis sartorius
what are the external rotators of the knee?
biceps femoris
What motions occur at the knee?
flexion/extension- sagittal plane, coronal axis
internal/external rotation- transverse plane, vertical axis
What are the open chain arthrokinematics of the tibiofemoral Joint?
concave tibia moves on convex femoral condyles
extension-anterior glide
flexion-posterior glide
What are the open chain arthrokinematics of the tibiofemoral joint?
convex femoral condyles moving on concave tibia.
extension-posterior glide
flexion-anterior glide
What is the screw home mechanism with a fixed femur?
during the final 30 degrees of knee extension, the tibia externally rotates 10 degrees on the femur in the transverse plane (open chain)
What is required to unlock the knee in the screw home mechanism?
flexion which is accomplished by the popliteus muscle
What factors are creating motion in the screw home mechanism?
shape of medial condyle
tension of ACL
Lateral pull of the quads
What occurs during open kinematic chain at the knee?
lateral tibial condyle moves posteriorly
medial tibial condyle moves anteriorly slightly
results in external rotation of the tibia
What occurs during closed kinematic chain at the knee?
lateral femoral condyle spins slightly
medial femoral condyle glides posteriorly
results in internal rotation of femur on the fixed tibia
What is the normal joint position of the knee?
normal Genu Valgum
shaft of femur angles medially due to inclination of femur
knee assumes a slight valgus position
What are some frontal plane abnormalities at the knee?
excessive genu valgum-greater than 15 degrees valgus position
genu varum- reversal of the genu valgum position
What are some sagittal plane changes that can occur at the knee?
genu recurvatum
What is genu recurvatum?
excess motion in extension (normal to have 5-10 degrees of hyperextension)
What’s normal patellofemoral alignment when the knee is in full extension (last 20-30 degrees)?
patella lies in front of the intercondylar groove
contact on the femur is at the inferior patellar pole
What’s normal patellofemoral alignment when the knee is flexed between 60-90 degrees?
Patella shifts below intercondylar groove
contact on the femur shifts inferiorly to the mid-patella
what’s normal patellofemoral alignment when the knee is flexed at 135 degrees?
patella is well below the intercondylar groove
contact on the femur is at the odd facet and lateral edge.
What’s the Q-angle stand for?
Quadriceps angle
What is the Q-angle?
the angle at which the quadriceps pull on the tibia.
How is the Q-angle measured?
by comparing the line from the ASIS to the mid-patella and the line from the mid-patella to the tibial tuberosity. The patella is pulled to the side of the angle.
What are the normal degrees of Q-angles for men and women
Men-14 degrees
Women- 17 degrees
What is the length tension relationship when the hip is flexed and the knee extended?
Rectus femoris is actively overshortened
Hamstrings are passively overstretched
what is the length tension relationship when the hip is extended and the knee is flexed?
hamstrings actively overshortened
Rectus femoris is passively overstretched.
