The Knee

Question 1

what type of joint is the knee join

Answer 1

synovial joint, largest in body

Question 2

what two articulations make up the knee, what are the functions

Answer 2

1) tibio-femoral joint, weight bearing
2) patello-femoral joint, pull of quadriceps femoris muscle to be directed anteriorly over the knee to tibia without tendon wear

Question 3

what type of bone is the patella

Answer 3

sesamoid bone

Question 4

flexion/extension

Answer 4

-occurs around sagittal axis
-open chain, tibia moves
-closed chain, femur moves

Question 5

patella and PFJ during flexion and extension

Answer 5

-flexion, patella moves inferiorly
-extension, patella moves superiorly

Question 6

hyaline cartilage

Answer 6

covers condyles of tibia and femur

Question 7

patellar groove

Answer 7

V-shape

Question 8

are femoral condyles convex or concave

Answer 8

convex

Question 9

are tibial condyles convex or concave

Answer 9

concave

Question 10

menisci structure

Answer 10

-fibrocartilaginous, C-shaped, wedged
-firmly secured to tibial condyles at edges, more mobile deeper into joint

Question 11

medial meniscus attachment

Answer 11

attaches at its edge to joint capsule and medial collateral ligament

Question 12

lateral meniscus attachment

Answer 12

no capsular attachment, more mobil than medial

Question 13

menisci function

Answer 13

-triple area of joint contact
-expand outward on weight bearing
-reduces pressure across knee
-cup shape, deepen articular surface of knee, stabilize joint, reduce ligament strain

Question 14

knee joint capsule

Answer 14

-encloses articular cavity and intercondylar region
-partly formed and reinforced by extensions from tenons of surrounding muscles

Question 15

medial knee joint capsule

Answer 15

-blends with MCL
-attaches to medial meniscus

Question 16

stratum fibrosum

Answer 16

-lateral knee joint capsule
-separated from fibular collateral ligament
-does not attach to lateral meniscus

Question 17

anterior knee joint capsule

Answer 17

-attached to margins of patella ligament

Question 18

posterior knee joint capsule function

Answer 18

-prevent hyperextension

Question 19

two major ligaments or thickenings of posterior capsule

Answer 19

1) arcuate ligament
2) oblique popliteal ligament, extension of semimembranosus tendon

Question 20

intracapsular ligaments

Answer 20

-in intercondylar region of knee, interconnect the femur and tibia
-ACL
-PCL

Question 21

ACL attachment

Answer 21

-attaches to a facet on anterior intercondylar eminence (tibia)
-ascends posteriorly to attach to facet at posterior lateral wall of intercondylar fossa (femur)
-intracapsular

Question 22

PCL attachment

Answer 22

-attaches to posterior aspect of intercondylar eminence (tibia)
-ascends anteriorly to attach to medial wall of intercondylar fossa (femur)
-intracapsular

Question 23

ACL functional significance

Answer 23

-resists anterior translation of tibia
-resists posterior translation of femur relative to a fixed tibia in a closed chain perspective
-prevents hyperextension

Question 24

PCL functional significance

Answer 24

-resists posterior translation of tibia
-resists anterior translation of femur over a relatively fixed tibia in a closed chain perspective
-prevents hyperflexion

Question 25

collateral ligament functions

Answer 25

stabilize hinge like motions of flexion and extension

Question 26

LCL attachment

Answer 26

-attaches superiorly at lateral femoral epicondyle -inferiorly attaches to lateral surface of fibular head -separated from capsule by popliteus tendon -extracapsular

Question 27

MCL attachment

Answer 27

-attached by much of its deep surface to underlying joint capsule -superiorly attaches to medial femoral epicondyle just inferior to adductor tubercle -inferiorly attaches to medial Margi and medial surface of tibia -extracapsular

Question 28

MCL function

Answer 28

-resists valgus producing forces -taut in full extension, assist with locking knee

Question 29

LCL function

Answer 29

-resists varus producing forces -taut in full extension, assist with locking knee

Question 30

patella retinacula

Answer 30

-thin connective tissue -medial and lateral to patella, superficial

Question 31

extracapsular posterior ligaments

Answer 31

-arcuate ligament -oblique popliteal ligament, extension of semimembranosus tendon

Question 32

patella

Answer 32

-sesamoid bone -transmits quadricep force across knee -enhances leverage of quad muscle

Question 33

knee rotations

Answer 33

-horizontal plane -internal -external

Question 34

screw home mechanism of knee rotation

Answer 34

-locking the knee reduces muscular demand during standing, 2 mechanisms -1-medial rotation of femur on tibia during extension, tighten ACL and collateral ligaments -2-shape of femoral condyles, knee extends and surfaces move to inferior femoral condyles, medial rotation provides stable knee, popliteus unlocks knee with lateral rotation of femur on tibia

Question 35

suprapatellar bursa

Answer 35

-articular cavity superiorly between distal shaft of femur and quadriceps femoris muscle and tendon

Question 36

prepatellar bursa

Answer 36

-subcutaneous and anterior to patella

Question 37

infrapatellar bursae

Answer 37

-deep and subcutaneous -sides of patellar ligament

Question 38

pes anserine bursa

Answer 38

-medially on proximal tibia -pes anserine is insertion for gracilis, sartorial, semitendinosis -bursa prevents friction between 3 tendons and tibial plateau

Question 39

fat pads

Answer 39

-protection around knee joint -capsule separated from patellar tendon by infra patellar fat pad

Question 40

circumflex

Answer 40

branches off major artery that surrounds something