Knee Joint Flashcards Preview

Leg > Knee Joint > Flashcards

Flashcards in Knee Joint Deck (45):

Which actions does the knee joint allow for?

flexion & extension
(v small amounts of medial & lateral rotation)


What are the articulations within the knee joint?

patella, femur, tibia


What does the shape of the knee joint suggest?

it is weak and relies on muscles and ligaments to ensure stability


Which muscles have a common distal attachment to the base of the patella?

quadriceps femoris (anterior thigh muscles)


How many articulations are there in the knee and what are they?

tibiofemoral and patellofemoral
(tibia with femur) and patella with femur


Describe the tibiofemoral articulating surface

medial and lateral condyles of femur articulate with tibia


Describe the patellofemoral articulation

anterior and distal part of femur articulate with patella


What is the main function of the tibiofemoral joint?

weightbearing joint of the knee


What does the patellofemoral joint allow?

the tendon of the quadriceps femoris (anterior thigh - extensors at knee) to insert directly over the knee
increases the efficiency of the muscle

both joint surfaces lined with hyaline cartilage & enclosed within single joint cavity


Where is the patella formed? how is this beneficial?

inside the tendon of quadriceps femoris
minimises wear & tear on the tendon


What are the functions of the lateral and medial menisci? What type of structures are they?

fibrocartilage structures
1. deepen the articular surface of the tibia - increasing stability
2. shock absorbers


What shape are the menisci and where do they attach?

C shaped
attached at both ends to the intercondylar area (between 2 condyles) of the tibia


Where else is the medial meniscus attached to apart from the intercondylar attachment? what does this result in?

attached to the tibial collateral ligament and the joint capsule
any damage to the tibial collateral ligament results in tearing of the medial meniscus


Why is the lateral ligament fairly mobile?

only attaches to the intercondylar eminence of the tibia


What is a bursae?

a synovial fluid filled sac found between moving structures of a joint to reduce wear and tear on the structures of the joint


How many bursae are there in the knee joint and what are they?

1. suprapatella bursae
2. prepatella bursa
3. infrapetella bursa
3. semimembranosus bursa


Describe the suprapatella bursa

extension of the synovial cavity of the knee, located between the quadriceps femoris and the femur
(prevent quadriceps femoris from rubbing on the femur)


Describe the prepatella bursa

between apex of patella and skin


Where is the infrapatella bursa?

split into deep and subcutaneous (superficial)
deep bursa lies between tibia & patella ligament
subcutaneous bursa lies between patella ligament and skin


Where is the semimembranosus bursa?

located posteriorly in the knee joint
between semimembranosus muscle (deep medial posterior thigh) and the medial head of the gastrocnemius (posterior leg)


What are the major ligaments of the knee joint?

1. patellar ligament
2. collateral ligament
3. cruciate ligament


What and where is the patella ligament? Where does it attach to?

a continuation of the quadriceps femoris tendon distal (beneath) to the patella
attaches to the tibial tuberosity (anterior superior tibia)


What are the collateral ligaments' function?

2 trap-like ligaments either side of the knee joint
stabilise the hinge motion of the knee (extend and flex), preventing any medial or lateral movements


Where is the tibial (medial) collateral ligament found? attachments?

a wide and flat ligament, found on medial side of the joint
proximally: attaches to medial epicondyle of femur
distally: medial surface of tibia


Where is the fibular (lateral) collateral ligament found? attachments?

thinner & rounder than the tibial collateral ligament
attaches proximally to the lateral epicondyle of the femur
distal: attach to depression on the lateral surface of the FIBULAR HEAD


What are the cruciate ligaments?

2 ligaments connecting the femur to the tibia
cross over each other - hence 'cruciate'


Where is the anterior cruciate ligament found? attachments? function?

posterior intercondylar fossa of femur to the anterior intercondylar region of the tibia

prevents anterior dislocation of tibia in relation to the femur


Where is the posterior cruciate ligament found? attachments? function?

anterior intercondylar fossa of femur to posterior intercondylar region of tibia
prevents posterior dislocation of the tibia onto the femur


What are the movements of the knee joint?

1. extension
2. flexion
3. lateral rotation
4. medial rotation


Which muscles carry out the extension of the knee?

quadriceps femoris - inserts into tibial tuberosity via the patella


Which muscles carry out the flexion of the knee?

hamstrings: semimembranosus, semitendinosus, biceps femoris
popliteus, sartorius, gracilis (all cross the knee joint)


Which muscles carry out the lateral rotation of the knee?

biceps femoris


Which muscles carry out the medial rotation of the knee?

semimembranosus, semitendinosus, gracilis, sartorius, popliteus


When cn lateral and medial rotation occur?

when the knee is flexed - otherwise only occurs at the hip joint


What type of joint is the knee joint?

bicondylar type synovial joint


Clinical: injury to the collateral ligaments
what causes injury to the collateral ligaments?

caused by force being applied to the side of the knee when the foot is placed on the ground


How can damage to the collateral ligament be assessed?

by asking the patient to medially rotate and laterally rotate the leg (flexed at knee)
pain on medial rotation = damage to medial (tibial) collateral ligament
pain on lateral rotation = damage to lateral (fibular) collateral ligament


What is likely to be damaged if the tibial (medial) collateral ligament is damaged?

medial meniscus - as the medial meniscus is attached to the tibial collateral ligament


how can the anterior cruciate ligament be torn?

1. hyperextension of the knee joint
2. application of a large force to the back of the knee with the joint partly flexed


How do you test for anterior cruciate ligament (ACL) damage?

perform an anterior drawer test
attempt to pull the tibia forwards - if it moves then the ligament has been torn


What is the most common way to damage the posterior cruciate ligament (PCL)?

1. 'dashboard' injury
when knee is flexed and a large force is applied to the shins - pushing the tibia posteriorly
seen in car accidents when knee hits dashboard
2. hyperextension of the knee joint
3. damage to the upper part of tibial tuberosity (insertion of quadriceps femoris - used for extension)


How do you test for posterior collateral ligament damage?

perform posterior draw test
clinician holds the knee in flexed position, and pushes the shin POSTeriorly
if there is movement then the PCL has been damaged


What can cause inflammation of the prepatella bursae?

friction between the skin and the patella - cause prepatella bursa to become inflamed - producing swelling on anterior side of knee
'housemaids knee'


What can cause inflammation of the (subcutaneous) infrapatella bursa?

friction between the skin and tibia
'clergyman's knee'


What is the unhappy triad?

due to the medial collateral ligament attached to the medial meniscus, damage to the collateral can damage the fibrocartilaginous structure
if there is a lateral force on an extended knee, the anterior cruciate ligament (ACL) can also be damaged, causing the 'unhappy triad'