Knee joint

Question 1

Basics

Answer 1

round femoral condyles on top of flat tibial condyles

unstable so menisci (fibrocartilage) divide joint onto two compartments the supra and inframeniscal

Question 2

Patellar ligament (extracapsular)

Answer 2

Patella to tibial tuberosity

anterior support; stretched during knee flexion

Question 3

Lateral Collateral Ligament (LCL) (extracapsular)

Answer 3

Lateral femoral epicondyle to apex of fibula

Taut during extension; lateral support

Question 4

Medial Collateral Ligament (MCL) (extracapsular)

Answer 4

Medial femoral epicondyle to medial meniscus and tibia;

taut during extension; medial support

Question 5

Oblique popliteal ligament (extracapsular)

Answer 5

Semimembranosus tendon to lateral joint capsule;

resists hyperextension

Question 6

Medial meniscus (intracapsular)

Answer 6

intercondylar area of tibia, tibial plateau, MCL

Receives medial femoral condyle; translates on tibia and rotates with femur during knee motion

Question 7

Lateral meniscus (intracapsular)

Answer 7

intercondylar area of tibia, tibial plateau, lateral femoral condyle via meniscofemoral ligament

Receives lateral femoral condyle; translates on tibia and rotates with femur during knee motion

Question 8

ACL (intracapsular)

Answer 8

Anterior intercondylar eminence of tibia to medial surface of later femoral condyle (up and out)

Taut during extension; resists anterior dispalcement of tibia on fixed femur and vice versa

Question 9

PCL (intracapsular)

Answer 9

Posterior intercondylar eminence of tibia to lateral surface of medial femoral condyle (up and in)

taut in flexion and extension; resists posterior displacement of tibia on fixed femur and vice versa

Question 10

Fixed femur knee movement

Answer 10

tibia moves on the femur

Question 11

Fixed tibia knee movement

Answer 11

femur moves on the tibia

Question 12

Knee extension notes

Answer 12

Lateral femoral condyle is smaller than medial femoral condyle so it continues to roll and rotates the femur medially and locks knee in full extension. Unlocking needs muscle action. Popliteus muscle laterally rotates femur on tibia to unlock.

Question 13

Knee flexors

Answer 13

Main: hamstings: semitendinosus, semimembranosus and biceps femoris

lesser: gracilis, sartorius, popliteus

Question 14

Knee extensors

Answer 14

Main: quadriceps femoris: rectus femoris and vasti medialis, intermedialis and lateralis

Question 15

Medial knee rotators

Answer 15

main: popliteus, semitendinosus, semimembranosus
lesser: sartorius, gracilis

Question 16

Lateral knee rotators

Answer 16

biceps femoris