knee Flashcards
what type of joint is the knee?
a modified hinge joint that allows flexion, extension, and slight internal/external rotation
what is the largest and strongest bone of the body? what does it articulate with?
femur
patella bone and proximal tibia
what are the medial and lateral condyles of the distal femur covered in?
articular cartilage
what is the intercondylar fossa?
popliteal surface?
posterior groove between the condyles where vessels travel
creates the floor of the pop fossa on posterior surface
where and what is the tibial tuberosity?
on the anterior tibia, and is the insertion site for the patellar ligament
what are the 3 articular surfaces of the proximal tibia?
medial condyle
lateral condyle
fibular cartilage: surface on inferior aspect of lateral condyle (forms the tibiofibular joint)
what is the largest sesamoid bone in the body?
patella (kneecap)
embedded in the quad tendon on the anterior knee
what is the function of the patella?
strengthens the quad tendon for powerful knee extension and reduces friction between the tendon and knee joint
what is the insertion site of the biceps femoris?
apex of the fibular head (lateral side)
what is the interosseous membrane?
the membrane that separates the posterior and anterior leg muscles
also stabilizes the lower leg
what 4 muscles make up the quad tendon?
rectus femoris (front and center)
vastus medialis
vastus lateralis
vastus intermedius (deep to rectus)
how much of the common quad tendon inserts on the patella bone?
95%
other 5% travel over the top and contribute to the patellar tendon
where is the femoral articular cartilage seen?
on anterior/inferior surface of femur in the trochlear groove between the condyles
provides patellar stability and is covered by articular cartilage
where is the patellar tendon seen?
is it a tendon or ligament?
between the apex of patella and the tibial tuberosity
attached medially and laterally by the patellar retinaculum
technically a ligament
what is the size of the patellar tendon?
4x2x6cm
where is the Hoffa fat pad?
posterior to the patellar tendon
intracapsular but extra-synovial
what are the bursae of the patella?
prepatellar: lines superficial surface, not seen if normal
infrapatellar: between distal patellar tendon and anterior aspect of tibial epiphysis, trace fluid is normal
what is the other name for the tibial collateral ligament? where is it?
medial collateral ligament, between the medial condyle or femur and anterior aspect of medial tibia
what do the deep fibers of the MCL attach to?
the medial meniscus
what are the medial and lateral meniscus made of?
crescent shaped bands of thick, rubbery cartilage on the superior border of the tibial bone
acts as shock absorbers and stabilizes the knee
what is another name for the fibular collateral ligament?
lateral collateral ligament
attaches the lateral condyle of the femur to the fibular head
is NOT attached to the lateral meniscus
what does the LCL share a common insertion site with?
biceps femoris
what action of the knee does the biceps femoris have?
where do both heads of the biceps femoris insert?
flexion of the knee
inserts on lateral/anterior head of the fibula, superficial to the LCL and popliteus tendon
what is the iliotibial band and where does it run?
broad thin fibrous band that connects the iliac crest to tibia
where does the iliotibial band insert?
(which tubercle)
lateral tibial condyle: Gerdy’s tubercle
what is the function of the iliotibial band?
supports internal hip rotation, flexion and extension while running
supports the knee while standing
where is the common site for friction of the iliotibial band?
over the lateral condyle of the femur
susceptible to inflammation with overuse
what are the tendons of the posterior knee?
semiteninosus muscle: part of the hamstrings responsible for extension
gracilis and semimenbranosus: flexes knee
what is the nerve on the posterior knee?
saphenous nerve
crosses posteriorly and superficially over the tendons
what is the bursa that causes a bakers cyst when extending with fluid?
semimembranosus and gastroc bursa of the posterior knee
what is the popliteal neurovascular bundle composed of?
tibial nerve: branch of sciatic nerve
popliteal vein and artery
nerve can be damaged if the tibia suffers a fracture
what does the sciatic nerve divide into at the popliteal crease?
common peroneal nerve and tibial nerve
what does the common peroneal nerve divide into?
divides into superficial and deep branches that run over the fibular head, then deep to the peroneus muscle
what does the peroneal nerve innervate?
front and side of the lower side, top of the foot
what needs to be evaluated when a patient presents with swelling of the knee?
suprapatellar recess
excess fluid can cause feeling of fluid in the knee
what causes quad tendon rupture?
from excess force injuries
what are the underlying conditions that can weaken the tendons?
diabetes, gout or RA
where do quad tears generally occur?
usually 1-2cm from insertion on patella
Where do MCL tears occur?
LCL tears?
-superiorly from joint space
- anywhere along the length of the tendon
generally not treated
where do friction tendinopathies of the IT band most often occur?
what is the second most common part?
lateral condyle of the femur
Gerdy’s tubercle
what pathology of the meniscus can be evaluated by ultrasound?
tears, meniscal cysts or an extruded meniscus
what is the 2nd most common pathology of the knee?
patellar tendinopathy:
jumpers knee: tendinopathy of the insertion
full/partial tears
degenerative changes of proximal deep fibers associated with calcific enthesopathy
complete rupture is rare
what is the most frequently encountered pathology of the knee?
bakers cyst
what can cause a bakers cyst?
prior surgery
obesity
trauma
advanced age
how does a bakers cyst present?
palpable mass in pop fossa with or without pain
