Knee and Thigh

Question 1

What does the mechanical load-bearing axis refer to?

Answer 1

weight bearing; the path of force bearing starting the the centre (widest) part of the femoral head to the foot (talus)

Question 2

What is the hip knee angle? (MAT and MAF)

Answer 2

MAF= mechanical axis of the femur (start of femoral head and goes to centre of the femoral condyles, intercondylar notch)
MAT= mechanical axis of the tibia (from midpoint of tibial spines to the centre of the talus)

Question 3

What is the anatomical axes?

Answer 3

lines along the shafts- femur and tibia

Question 4

What is genu recurvatum?

Answer 4

deformity in the knee joint, so that the knee bends backwards (excessive extension occurs at the knee joint)

Question 5

What are the bones involved in the knee joint?

Answer 5

femur, tibia, fibula, patella

Question 6

What are joints in the knee joint?

Answer 6

tibiofemoral joint, patellofemoral joint, superior tibiofibular joint

Question 7

What are fat pads?

Answer 7

space filler in areas that change shape a lot and avoid the patella ligament or other things getting impinged

Question 8

What does the tibiofemoral joint consist of?

Answer 8

femoral condyles and tibial plateau

Question 9

What is the joint classification of the tibiofemoral joint?

Answer 9

bicondylar (predominantly uniaxial)

Question 10

What are the actions of the tibiofemoral joint?

Answer 10

mainly F-E in sagittal plane (coronal axes), and limited rotation around vertical axis

Question 11

What is the screw-home mechanism?

Answer 11

medial rotation of femur on tibia tightens ligaments which essentially locks your femur and tightens your ligaments and your capsule; good stability

Question 12

What is extensor moment?

Answer 12

flat surface of femoral condyles with tibia and stabilise joints

Question 13

Why is the shape of femoral condyles important?

Answer 13

it is flat on flat in extension so it creates stability

Question 14

What is the functions of the tibiofemoral menisci?

Answer 14

increase congruency/contact area between femoral condyles and tibial plateau; decreases stress; protects articular cartilage

Question 15

Why is the tibiofemoral menisci needed?

Answer 15

discrepancy of the shape of femoral condyles and the flat tibial plateau so there is the fibrocartilage structure interposed to create better contact area; therefore same amount of load distributed over a great area= same force, over greater area means less stress

Question 16

Why is it important for there to be fibrocartilage in the meniscus?

Answer 16

fibrocartilage is deformable without tearing as readily as hyaline cartilage (fibrocartilage protects underlying hyaline cartilage)

Question 17

What is the differences between the medial and lateral meniscus?

Answer 17

medial- longer in anterior-posterior direction, larger posterior horn, more capsule attachment
lateral- more variable and mobile as it doesn’t have as much capsular attachment

Question 18

When will you have greater contact between the femoral condyles and posterior horn?

Answer 18

Flexion (greater weight bearing of posterior horn in flexion)

Question 19

Which meniscus provides greater coverage of its plateau? Consequences?

Answer 19

lateral gives greater protection to its tibial condyle. consequence- bigger medial femoral condyle and tibial condyle but don’t have as effective coverage of the tibial condyle of the articular surface on the medial meniscus

Question 20

What are the tibiofemoral ligaments?

Answer 20

tibial collateral (medial) ligament, fibular collateral (lateral) ligament, anterolateral ligament, anterior cruciate ligament, posterior cruciate ligament, oblique popliteal

Question 21

What does the tibial collateral ligament (medial) resist?

Answer 21

resists valgus

Question 22

What does the fibular collateral ligament (lateral) resist?

Answer 22

resists varus

Question 23

What does the anterolateral ligament resist?

Answer 23

resists tibial IR in 30 degrees F

Question 24

What does the anterior cruciate ligament resist? what are the two fibre bundles?

Answer 24

fibre bundles: posterolateral band (PLB), anteromedial band (AMB)
resists anterior translation of tibia on femur, resists posterior translation of femur on tibia, resists valgus, will tighten in end range extension

Question 25

What does the posterior cruciate ligament resist?

Answer 25

resists posterior translation of tibia on femur, resists femur moving forward on tibia

Question 26

What are the muscles of the anterior thigh?

Answer 26

sartorius, rectus femoris, vastus intermedius, vastus lateralis, vastus medius

Question 27

What are the muscles of the posterior thigh?

Answer 27

biceps femoris, semimembranosus, semitendinosus

Question 28

What are the muscles of the posterior leg?

Answer 28

gastrocnemius, plantaris, popliteus

Question 29

What are the medial thigh and knee muscles?

Answer 29

pes anserinus: sartorius, gracilis, semitendinosus

Question 30

What are the lateral thigh and knee muscles?

Answer 30

tensor fascia latae- iliotibial band, biceps femoris

Question 31

What structures (active and passive) provide resistance to anterior translation of tibia on femur?

Answer 31

ACL, menisci, hamstrings

Question 32

What structures (active and passive) provide resistance to posterior translation of tibia on femur?

Answer 32

posterior tibial, PCL, menisci, quadriceps

Question 33

What structures (active and passive) provide resistance to tibiofemoral hyperextension?

Answer 33

oblique popliteal ligament, ACL, PCL

Question 34

What structures (active and passive) provide resistance to tibiofemoral valgus?

Answer 34

width of TF jt, TCL superficial>deep, ACL, PCL, semimembranosus, semitendinosus, sartorius, gracilis

Question 35

What structures (active and passive) provide resistance to tibiofemoral varus?

Answer 35

width of TF jt, FCL, ACL, PCL, posterolateral capsule, menisci, ITB, popliteus

Question 36

What structures (active and passive) provide resistance to IR of tibia on femur?

Answer 36

ACL, ALL, menisci, bicep femoris

Question 37

What structures (active and passive) provide resistance to ER of tibia on femur?

Answer 37

ACL, menisci, semimembranosus, semitendiosus, popliteus, sartorius, gracilis