the knee Flashcards
the tibiofemoral joint is the articulation between
This is part of the knee joint!
articulation of the femur with the tibia
specifically, the medial and lateral condyles of the tibia and the medial and lateral condyles of the femur
what kind of joint is the tibiofemoral (TF) joint?
This is part of the knee joint
a modified hinge joint (aka synovial condlylar)
- the tibia glides under the femur, but some rotation occurs as we move from flexion to extension
the patellofemoral joint is the articulation between
This is also part of the knee joint!
the patella and the intercondyler notch of the femur behind it
what kind of joint is the patellofemoral joint?
This is also part of the knee joint!
it’s a gliding joint
the proximal tibiofibular joint is the articulation between
the proximal fibula and the lateral condyle of the tibia
The femur and fibula don’t actually attach. But there is a ligament that connects them called the
lateral collateral ligament
In terms of the tibiofemoral joint, the bottom of the femur has what between that and the tibia?
the bottom of the femur has femoral condyles. There is a lot of hyaline cartilage at the end of these bones (helps with blood supply).
Does the tibia or fibula support our body weight?
the tibia
What is the most injured joint in the body?
the tibiafemoral joint bc of degenerative joint disease
the intercondylar eminence
the top of the tibia (looks like Rocky Mountains) that goes into the condylar notch of the femur and help directs motion
range of motion of the knee
0-160 degrees (more than 0 = flexion)
flexion of knee
bend towards your tush
extension of knee
straightening knee - up to 0
Both articular facet surfaces of the tibia have a corresponding _____
meniscus (a lateral and a medial meniscus)
ontop of flexion and extension the knee also has
“the screw home mechanism”
flexion has 25 degrees of medial rotation (turns inward)
extension has 25 degrees of lateral rotation (turns outward)
fibula and tibia- which is lateral which is medial?
fibula is lateral to the tibia
the screw home mechanism of the knee is due to which muscle?
the poplitius muscle. When it contracts, it will medially rotates the tibia.
What kind of bone is the patella and why?
Its the largest sesamoid bone and its sesamoid because it is embedded in tendons (quad tendons to be exact)
the quadricep tendon
envelops the patella (it’s a line straight down over it)
the patellar ligament
a continuation of the quadricep tendon that takes it to the tibial tuberosity
if quadricep tendon contracts what will happen?
your leg will kick out into knee extension
the base of the patella vs the apex of the patella
the base is the broad top of the patella
the apex is the pointy bottom of the patella
On the posterior aspect of the patella, there is an articular surface. This allows it to articulate with the condylar notch. How is the articular surface of the patellar divided?
It is divided into medial and lateral facets. The facets are separated by a median vertical ridge
What is patellar tracking?
It is the patella moving in the intercondylar notch of the femur
When your leg is extended, what happens to the patella?
It is pulled up
If you flex your knee (aka hamstrings contract) what happens to the patella?
It is pulled down
The patella is thought to ___ the pull of the quadriceps
increase
chondromalacia patella
patellar shift and damage to the articular cartilage
(think of the pic where it moved laterally and Mcgowan said to think of the wear and tear every time its flexed and extended)
The fibrous capsule of the knee joint is, in general, quite thick. However, it is deficient _____ and is replaced by the fused tendons of the ____ musculature and its expansion
ANTERIORLY
replaced by the fused tendons of the QUADRICEPS
The articularis genu muscle, which consists of deep fibers of the vastus intermedius that attach into the capsule and innervated by the femoral nerve, DO WHAT?
pulls the fibrous knee capsule and bursa out of the joint when we extend the knee to prevent injury
what lines the fibrous knee capsule?
a synovial membrane
it does not cover articular surfaces
oblique popliteal:
extension of semimembranosus- attached above the lateral condyle of femur to the medial tibial condyle - forms the floor of popliteal fossa and is in contact with popliteal artery.
supports posterior knee
ACL and PCL are in or out of synovial membrane?
out, but they’re still inside the joint
infrapatellar fold
fold of synnovial membrane between the femoral condyles (intercondylar notch)
There are about 16 or so bursae around the knee. Name the 4 important ones
- suprapatellar- above the patellar. it lies on top of the distal portion of femur.
- prepatellar- “before the patella”. between the skin and over top of patella
- deep infrapatellar- a little below the prepatellar. Kind of over the patellar ligament
- superficial infrapatellar - lies between tibial tubercle and the overlying skin
housemaids knee
prepatellar bursitis
clergymans knee
infrapatellar bursitis (deep and superficial bursa)
bakers cyst
benign swelling of semimembranous bursa
- a synovial cyst being filled with fluid due to irritation. It tells us that there is some other derangement going on in body
ligamentum patellae
this is the patellar ligament.
It’s the continuation of quadriceps tendon, so it goes from inferior border of patella to tibial tuberosity;
the lateral (fibular) collateral ligament (LCL)
round cord ligament that goes from the lateral epicondyle of femur down to the head of the fibula. It doesn’t directly touch the joint, it leaves space for the tendon of popliteus. It is important for stability
Deep to the lateral collateral ligament is the
lateral meniscus
If the LCL is strained is the lateral meniscus?
no, because there is space between
The medial(tibial) collateral ligament (MCL)
MCL goes from the medial epicondyle of the femur and attaches to the medial condyle of the tibia.
If the MCL is strained will the medial meniscus be strained?
It likely will be because the MCL is attached to the meniscus
The MCL is crossed by which tendons? These tendons attach to the medial meniscus
the sartorius, gracilis and semitendinosus tendons
arcuate popliteal:
Y-shaped - from the posterior border of the intercondylar area of the tibia and the lateral epicondyle of femur to the area below the head of fibula.
form the floor of popliteal fossa
supports posterior knee
The cruciate ligaments are called cruciate because they
cross each other
anterior cruciate:
anterior intercondylar area of tibia, runs superiorly, posteriorly and laterally to the posterior part of the medial surface of the lateral femoral condyle.
stability for rotary
posterior cruciate:
posterior intercondylar area of tibia, runs superiorly, anteriorly and medially to the lateral surface of the medial condyle of the femur.
stability
what are the Intracapsular Ligaments?
the anterior cruciate, the posterior cruciate and the menisci
The cruciate ligaments: are tight both in ____ and ____but are most relaxed at about 30 degrees of flexion, whereas the collateral ligaments are tight in ______ and relaxed in ____
cruciate- tight in BOTH flexion and extension
collateral- tight in extension but relaxed in flexion
the cruciate ligaments prevent
anterior and posterior displacement of tibia
the collateral ligaments prevent
abduction/adduction of the knee-joint
There is an anterior meniscofemoral ligament (Humphrey) and posterior meniscofemoral ligament (Wrisberg). What do they cushion?
also they are only present in 70% of knees
The PCL
I don’t really know what their purpose is
The medial meniscus is C shaped and bigger. Anteriorly, it attaches to the tibia by the _____ _____ ____ and posteriormedially it attaches to the fibrous capsule and deep surface of the tibial collateral ligament.
transverse genicular ligament
menisci work to deepen the surface and to direct motion
The lateral meniscus is more round and nearly a complete
ring. Anteriorly, it attaches to the tibia via the ____ ____ ____, and posteriomedially it attaches to the tendon of the
_______
Transverse genicular ligament
popliteus
menisci work to deepen the surface and to direct motion
ACL tear
hyperextension of knee
rotational injury
relaxed in 30 degrees flexion
-weaker than PCL, have poor blood supply,
anterior drawer test
test to see if there is ACL or PCL injury
if practitioner pulls tibia forward, it should have a stopping point. if it doesn’t, ACL tear.
If practitioner pulls tibia backwards, it should have a stopping point. If not PCL tear
transverse genicular ligament
attaches the lateral and medial menisci of the knee
menisci are ___ on the outside and ____ on the inside
bigger on the outside, smaller on inside, create a triangle shape
coronary ligaments of knee
pieces of the outer menisci that attach to the tibia
both MCL and PCL are ___ in extension
taught
unhappy triad of O’donohue
injury to ACL, medial meniscus, and medial collateral ligament
Hiltons law
know the nerves that innervate a joint, and then you should know the sensory innervation of the joint
On the femoral condyles there is a ____ _____- this is where the patella attaches
trochlear groove
On the back of the femur, there is a ____ _____/ fossa. Some parts of tibia fit nicely in this notch
intercondylar notch/ fossa
