The Knee Joint Flashcards
articulations for knee joint
2 femerotibial - medial and lateral
1 femeropatellar
what is the effect of hip extension on knee flexion?
limited knee flexion when extended due to loss of tension of hamstrings
requirements for rotation of knee:
knee is flexed and collateral ligaments are relaxed
what happens to the joint when approaching full extension
undergoes few degrees of medial rotation on the tibia
locks knee
how is the knee unlocked?
popliteus muscle which laterally rotates the femur
what is more stable knee movement?
extension as the surface of the tibial condyls is flat = tibial plateau
functions of menisci
increased joint congruency
distribute weight evenly shock absorption
assist locking mechanism
medial meniscus is attached to
the tibial collateral ligament
types meniscal tears
vertical transverse peripheral bucket-handle parrot-beak flap
ligaments inside the joint are called
e.g.
intra-articular
ant. + post. cruciate ligaments
ligaments outside the joint are called
e.g.
extra-articular
fibular + tibial collateral
posterior cruciate ligament features
post. intercondylar region of the tibia
travels superolaterally to medial femoral condyle
ant. cruciate ligament features
attaches to ant. intercondylar region of the tibia
travels supero-posteriorly to attach to the lateral femoral condyle
function of posterior cruciate
post - stops post displacement
prevents hyperflexion
how to damage post. cruciate ligament
damage when landing on tibial tuberosity when knee is flexed
function of anterior cruciate
prevents ant. displacement of tibia of femur
prevents hyperextension
to injure ant. cruciate ligament
occurs when knee is hyperextended and force is applied anteriorly
what does tibial collateral prevent
abduction of the leg at the knee
what does fibular collateral prevent
adduction of the leg at the knee
what causes the unhappy triad?
excessive lateral twisting of flexed knee
or
blow to lateral side of extended knee
what ligaments are damaged?
tears tibial collateral ligament which is attached to the medial meniscus, which then also tears
ACL may also tear as it is taught due to flexion
muscles of knee
quadriceps hamstrings (post thigh) sartorius gracilis iliotibial tract
where are the bursae?
Prepatellar bursa - in front of patella
Deep and superficial infrapatellar bursa - below patella
Suprapatellar bursa - behind patella in front of femur
What muscles pull superolaterally?
Rectus femoris
Vastus intermedius
Vastus lateralis
What muscles pull horizontally?
Pull of vastus medialis
why is dislocation more common in females?
pull of vastus lateralis is wider and more shallow because angle of femur (Q) in females is more oblique due to wider pelvis
Genu varum
Bow leg
Tibia adducted with respect to femur
Gene valgum
Knock knee
Tibia abducted with respect to femur
