Knee Flashcards
What does the knee as a region consist of?
Condyles of the femur and tibia, the patella, the fibular head and the popliteal fossa
what does the knee as a joint?
A hing type synovial joint, with gliding and rolling, and some rotation
What is the largest and most superficial joint of the body?
The knee
What are the two reasons the knee joint is one of the most vulnerable joints?
The articular surfaces are incongruous and there is a mechanical disadvantage resulting from bearing weight plus momentum while serving as a fulcrum between 2 long levers
What are some features of the knee that provide compensatory support?
Strong intrinsic, intracapsular and extracapsular ligaments, splinting by tendons and menisci
what is patellofemoral syndrome?
Knee pain resulting from microtrauma/osteoarthritis and improper tracking of the patella
what are the primary movements at the knee joint?
flexion and extension (combined with gliding and rolling)
is the tibia fixed or mobile?
tibia is in a fixed position and femur rotates on top of it
where are the medial and lateral femorotibial articulations?
between the corresponding condyles of the femur and tibia
are the medial and lateral femoral condyles concave or convex?
convex with the articular surface extending superiorly on the posterior aspect
what separates the medial and lateral femoral condyles?
intercondylar fossa
which femoral condyle is larger?
the medial
what is the superior tibial surface expanded by?
the presence of the medial and lateral condyles
describe the tibial plateau?
relatively flat for articulation with femur. medial side is actually slightly concave and lateral slightly convex. with an intercondylar area containing 2 tubercles
what attaches on the medial and lateral intercondylar tubercles of the tibial plateau?
menisci and cruciate ligaments
what attaches on the medial and lateral epicondyle of the femur?
the collateral ligaments
what keeps the knee joint stable?
musculature
when is the knee most stable?
when standing erect in extension
why is the knee most stable in extension?
the articulating structures are most congruent, the collateral and cruciate ligaments are taut and there is a splinting effect by the many surrounding tendons crossing the joint
what is the largest sesamoid bone in the body?
the patella
how many total facets are on the patella?
7
what does the patella provide?
a bony surface that is able to withstand compression placed on the quadriceps tendon during kneeling, and the friction occurring during repeated flexion/extension during running. it also moves the tendon more anteriorly than the tibial tuberosity and farther from the joint’s axis, providing for greater mechanical advantage
what are the 3 functions of the patella?
- dissipates force across anterior aspect of femoral condyles
- improves the mechanical efficiency of the quadriceps muscle
- occupy (“tracks in”) the intercondylar groove
where does the suprapatellar bursa lie?
deep to the tendon of the quadriceps femoris, superior to the knee
T/F: the suprapatellar bursa is continuous with the joint space
true
what could happen if theres an infection in the suprapatellar bursa?
bc it is continuous with the joint the infection could spread to the joint
what holds the suprapatellar bursa in place superiorly?
the articular muscle of the knee
what do the prepatellar and superficial infrapatellar bursae allow?
allow the skin to move freely around the knee as it bends
what is housemaids knee?
an inflammatory process which results from trauma (anyone who kneels a lot without protecting the area with knee pads is susceptible)
what does the infrapatellar fat pad do?
separates the deep infrapatellar bursa from the joint space
what kind of joint is the knee?
synovial with an external fibrous capsule and interanal synovial membrane
why is the external fibrous capsule of the knee incomplete at some spots?
example bc poplietus tendon pierces it
what does the internal synovial membrane of the knee do?
separates the inside of joint into medial and lateral compartments by “bunching up” anteriorly, covering the cruciate ligaments
what does intra-articular mean?
being within the synovium and in contact with sunovial fluid
where does the synovium attach?
at the edge of all the articular cartilage surfaces, including the deep surface of the patella
where is the capsule most defined?
posteriorly