Knee joint Flashcards
2 articulations of knee joint
Tibiofemoral (distal femur with proximal tibia) MAIN
Patellofemoral (distal femur with patella)
Type of joint that knee is
synovial
hinge (moves in 2 planes) flexion and extension
Stability changes in knee
when knee is extended = greater stability as there is a greater articulating surface (more contact between femur and tibia)
when knee is flexed - only round condyles are in contact
how is the knee joint supported?
ligaments
joint capsule
menisci
two menisci in knee
medial and lateral
what are menisci made of and what does this allow?
fibrocartilage
allows flexibility and they can change shape increasing congruity (surface contact) of the joint
other than increasing congruity, what is the other function of menisci?
Act as shock absorbers
Why are the medial and lateral menisci different?
medial menisci is connected to medial collateral ligament
medial menisci is less mobile than lateral
(lateral not attached to anything)
Extracapsular ligaments of knee
medial collateral
lateral collateral
Intracapsular ligaments of knee
anterior cruciate ligament
posterior cruciate ligament
where do the cruciate ligaments insert?
posterior - posterior tibia
anterior - anterior tibia
What do lateral collateral ligaments resist?
Varus strain (force pushing away from medial side)
what do medial collateral ligaments resist?
Valgus strain (force pushing towards medial side)
Bursa of the patella
Semimembranous Suprapatellar (above) Subcutaneous prepatellar (infront) Subcutaneous infrapatellar (below but superficial) Deep infrapatellar (below but deep) Subsatorial (pes anserinus)
Joint capsule of knee parts
Inner synovial membrane
Outer fibrous membrane