MSK 24 - Knee joint

Question 1

what are the 2 articulations in the knee joint

Answer 1

between the femur and tibia

between the femur and patella

Question 2

what is on the back of the patella where it articulates with the femur

Answer 2

back is covered in cartilage

Question 3

what movements are allowed by the knee joint

Answer 3

extension and flexion

no adduction or abduction

Question 4

where does the patella bone sit

Answer 4

in the tendon of quadriceps muscles

Question 5

where does the quadriceps tendon attach to distally

Answer 5

attaches to the tibial tuberosity of tibia

Question 6

what does the patella do

Answer 6

protect the quadriceps tendon on surface that rubs a lot

Question 7

what does the axis of the lower limb allow in terms of weight

Answer 7

weight of body is transmitted to centre of hip joints then down leg

Question 8

what demographics tend to have varus limb axis orientation

Answer 8

babies and old people

Question 9

what is varus orientation

Answer 9

apex of joint points out away from midline

Question 10

what is valgus orientation

Answer 10

apex of joint points in towards the midline

Question 11

what are the 5 major ligaments associated with the knee joint

Answer 11

patellar ligament/tendon

medial and lateral collateral ligaments

anterior and posterior cruciate ligaments

Question 12

where does the patellar ligament attach to

Answer 12

superiorly it is attached to inferior margins of patella

inferiorly it is attached to the tibial tuberosity

Question 13

what is the difference between ligaments and tendons in terms of attachment sites

Answer 13

tendon attaches muscle to bone

ligament attaches bone to bones in joints

Question 14

where do the medial collateral ligaments attach

Answer 14

from medial femoral epicondyle to medial tibia plateau (posterior to attachment of the pes ansernius)

Question 15

what does the MCL blend with at its insertion

Answer 15

it blends with the joint capsule and medial meniscus

Question 16

where do the lateral collateral ligaments attach

Answer 16

lateral femoral epicondyle to fibula head

Question 17

does the LCL blend with the joint capsule

Answer 17

no it is discrete

Question 18

what is the function of the MLC and LCL

Answer 18

prevents knee going valgus or varus

Question 19

are the cruciate ligaments intra or extracapsular

Answer 19

intracapsular

Question 20

where does the ACL attach

Answer 20

from anterior tibial spine to lateral condyle of femur

Question 21

where does the PCL attach

Answer 21

from posterior tibial spine to medial femoral condyle

Question 22

what does the ACL do

Answer 22

prevent tibia from sliding forward on the femur

Question 23

what does the PCL do

Answer 23

prevent posterior translation of tibia on the femur

prevents femur sliding forward on femur

Question 24

where are the cruciate ligaments relative to the knee joint and articular cavity

Answer 24

within knee joint

outside articular cavity (not inside the synovium)

Question 25

what side of the femur and tibia does the ACL to

Answer 25

lateral femur medial tibia

Question 26

what side of the femur and tibia does the PCL to

Answer 26

medial femur lateral tibia

Question 27

what is a joint capsule and where does it attach

Answer 27

fibrous membrane that encloses the articular cavity attaches where the cartilage finishes

Question 28

where is the pre patellar bursa

Answer 28

infront/anterior to the patella

Question 29

where is the infrapatellar bursa

Answer 29

superficial and deep to patella ligament - inferior to patella itself

Question 30

do the pre and infra patella bursa communicate with the knee joint

Answer 30

no

Question 31

which patella bursa is continuous with the knee joint

Answer 31

suprapatella

Question 32

where does the suprapatella bursa sit

Answer 32

between the quads tendon and the distal femur

Question 33

where will fluid often accumulate in a knee joint effusion

Answer 33

suprapatellar bursa

Question 34

what reinforces the suprapatella bursa anteriorly

Answer 34

quads tendon and patella ligament

Question 35

where is the synovial membrane of the suprapatella bursa relative to the fibrous membrane and cruciate ligaments

Answer 35

deep to fibrous membrane excludes anterior and posterior cruciate ligaments

Question 36

what material is the menisci made of

Answer 36

fibrocartilage

Question 37

what do the menisci - 2 things

Answer 37

increase articulation between femur and tibia as shape of surfaces change throughout the full range of motion act as shock absorbers

Question 38

what shape is the medial and lateral menisci in the knee

Answer 38

medial = moonshaped lateral = c shaped

Question 39

where is the medial meniscus attached

Answer 39

to joint capsule and MCL

Question 40

how mobile is the medial meniscus

Answer 40

not very mobile as its attached to the MCL

Question 41

which meniscus is larger

Answer 41

medial

Question 42

is the lateral meniscus attached to the joint capsule

Answer 42

no

Question 43

is the lateral meniscus mobile

Answer 43

yes as its not attached to the joint capsule of the knee

Question 44

do the menisci attach to the tibia - where and how

Answer 44

yes attach to tibia medially via ligaments anterior and posterior

Question 45

do you tear the ligament when you dislocate the patella

Answer 45

no

Question 46

what is a lipohaemarthrosis in terms of what causes it in the knee and what it looks like in a xray

Answer 46

caused by tibial plateau fractures in the knee bone marrow leaks out from fracture and communicates with the knee joint creates two layers top layer of fat above layer of blood

Question 47

where does the vascular supply to the knee come from what anstomoses together

Answer 47

(superiorly) branches of femoral, lateral femoral circumflex and popliteal vessels which anastomose with (inferiorly) anterior tibial and circumflex peroneal arteries

Question 48

the knee joint is supplied by which 3 nerves

Answer 48

femoral nerve sciatic nerve obturator nerve

Question 49

what is the L2 myotome responsible for

Answer 49

hip flexion

Question 50

what is the L3 myotome responsible for

Answer 50

knee extension

Question 51

what is the L4 myotome responsible for

Answer 51

ankle dorsiflexion

Question 52

what is the L5 myotome responsible for

Answer 52

great toe extension

Question 53

what is the S1 myotome responsible for

Answer 53

ankle plantarflexion

Question 54

what is the pattern of myotomal supply

Answer 54

muscles with the same action have commonly segmental supply ie all muscles taht act to do the same thing to a joint have the same myotome (or two)

Question 55

what muscles are responsible for knee - 6 groups (technically 8 muscles)

Answer 55

hamstrings (bicep femoris, semimembranosus and semitendinosus) gracilis sartorius grastrocnemius plantaris popliteus

Question 56

what muscles are responsible for knee extension - 2 groups

Answer 56

anterior compartment quads

Question 57

what muscles are responsible for knee medial/internal rotation of the leg

Answer 57

semimembranosus semitendinosis

Question 58

what muscles are responsible for knee lateral/external rotation of the leg

Answer 58

biceps femoris

Question 59

what is the clinical importance of pes ansernius

Answer 59

tendons can be used to reconstruct a torn ACLw

Question 60

what is the clinical importance of the unhappy triad

Answer 60

common injury pattern resulting from valgus/lateral force to knee

Question 61

what are the 3 structures involved in the unhappy triad

Answer 61

medial collateral ligament anterior cruciate ligament medial/lateral meniscus