Knee Part 2

Question 1

Articulation Patellofemoral Joint

Answer 1

Convex patellar facets
Concave trochlear groove of femur

Question 2

Patellofemoral Joint type

Answer 2

modified plane joint

Question 3

Movements that occur patellofemoral joint

Answer 3

Superior/inferior and medial/lateral translation

Question 4

Patellar stability is maintained by

Answer 4

bone, passive, and active structures

Question 5

Tibial on femoral movement
Patellofemoral Joint

Answer 5

Patella slides relative to fixed trochlear groove of femur

Question 6

femoral on Tibial movement
Patellofemoral Joint

Answer 6

• Trochlear groove of femur slides relative to the fixed patella

Question 7

Patellofemoral joint problems may be related to weakness of

Answer 7

hip muscles

Question 8

Patella acts as a ____ for the knee
increases quad power by _____ %

Answer 8

fulcrum
33-50

Question 9

Patella embedded in the

Answer 9

tendon of the quadriceps femoris

Question 10

Patella has _____ facets on articular surface

Answer 10

3

Question 11

At full knee extension patella sits on

Answer 11

anterior surface of distal femur (femoral sulcus) against the suprapatellar fat pad

No bony contact with condyles

Question 12

with knee flexed patella sits in ________ and contacts the ______

Answer 12

intercondylar notch, condyles

Question 13

Patellar Tracking Flexion

Answer 13

InFeriorlyand medially

Question 14

Patellar Tracking Extension

Answer 14

Superiorly and laterally

Question 15

Abnormal patellar tracking can occur with an imbalance in the activity of the of the

Answer 15

vastus medialis obliquus (VMO) relative to the vastus lateralis (VL)

Question 16

Most subluxations/dislocations of patella occur when the knee is

Answer 16

close to or fully extended, usually laterally secondary to the lateral pull of the quadriceps

Question 17

• Path of Patella and Areas of Contact
  
  • 135 deg knee flexion

Answer 17

Contacts the femur primarily in its superior pole

• Lateral facet and odd facet share articular contact with femur

Question 18

at 135 deg of knee flexion the patella rests well below the trochlear groove, lodged in the

Answer 18

intercondylar notch of femur

Question 19

Path of Patella and Areas of Contact
90 deg knee flexion

Answer 19

Primary contact region starts to migrate to its inferior pole

Question 20

Path of Patella and Areas of Contact
90-60 deg knee flexion

Answer 20

Patella engaged within the trochlear groove of femur

Contact area between patella and femur is greatest (1/3 of total surface area contact)

Large level of joint compression secondary to quadriceps activation

Question 21

Patellofemoral joint compressive forces across functional tasks:

Answer 21

• Walking on level surfaces:
  1.3 x BW
• SLR exercise:
  2.6 x BW
• Climbing stairs:
  3.3 x BW
• Squats:
  7.8 x BW

Question 22

Interrelated factors associated with joint compression
Patellofemoral joint

Answer 22

Knee flexion angle and quadriceps muscle force

Question 23

Patellofemoral Joint Compressive stress is greatest at

Answer 23

60º-90º knee flexion

Question 24

The net lateral pull exerted on the patella by the quadriceps is indicated by the

Answer 24

Q angle

Question 25

The larger the Q-angle, the greater the

Answer 25

lateral muscle pull on the patella

Question 26

Local Factors Across PFJ Lateral Directed Forces

Answer 26

IT Band Lateral patellofemoral ligaments Bowstringing force on the patella Lateral patellar retinacular fibers

Question 27

Local Factors Across PFJ Medial Directed Forces

Answer 27

Vastus medialis (oblique fibers) Medial patellofemoral ligaments medial patellar (retinacular fibers)

Question 28

- Global Factors Across PFJ that can increase the Q-angle

Answer 28

Excessive knee valgus and knee ER

Question 29

Increased Knee ER can occur as a combo of excessive

Answer 29

femur IR Tibial ER

Question 30

- Patella Alta and Baja - Ratio of the distance between the

Answer 30

patella and the tibia to the length of the patella

Question 31

Patella Alta –

Answer 31

increased distance

Question 32

Patella Baja

Answer 32

decreased distance

Question 33

Meniscus Function

Answer 33

Improve tibiofemoral congruence Increase joint stability during motion Help guide arthrokinematics of the knee Help distribute WB forces (50-70% of load) and decreases pressure on articular cartilage in the knee joint Help lubricate articular cartilage in the knee Provides proprioception

Question 34

WITHOUT Meniscus

Answer 34

Contact area would reduce by 50% (stress will increase in smaller area on the joint —> OA) Load on femoral condyle doubled Load on tibial condyle may increase 6-7 times Friction increases by 20%

Question 35

Medial Meniscus

Answer 35

C-shaped (oval) Open toward intercondylar tubercles Its external border attach to MCL and adjacent capsule

Question 36

Lateral Meniscus

Answer 36

Circular shape Its external border attach to lateral capsule Popliteus tendon pass between LCL and the external border of lateral meniscus

Question 37

Both menisci are connected anteriorly by

Answer 37

transverse ligament

Question 38

Meniscus Attached to patella via

Answer 38

patellomeniscal ligaments (ant. capsular thickenings)

Question 39

Meniscus attached to periphery by

Answer 39

coronary ligaments

Question 40

Medial Meniscus is ______ mobile than lateral meniscus

Answer 40

less more injury prone than lateral meniscus

Question 41

What muscles attach to both menisci?

Answer 41

Quadriceps and semimembranosus

Question 42

Popliteus attaches only to the

Answer 42

lateral meniscus

Question 43

The meniscus is well vascularized during

Answer 43

1st year of life once WB, begins to decrease

Question 44

Meniscus The peripheral (outer) 1/3 is

Answer 44

vascularized (“red zone”)

Question 45

Mensicus The central (inner) 2/3 is

Answer 45

avascular (white zone)

Question 46

Central inner 2/3 of meniscus receives nourishment from

Answer 46

synovial fluid

Question 47

Meniscus is well innervated with

Answer 47

free nerve endings and mechanoreceptors

Question 48

With meniscus injuries, proprioceptive deficits may potentially occur

Answer 48

after injury

Question 49

Most often cause of tears of the menisci

Answer 49

forceful axial rotation of femoral condyles plus a valgus force over a flexed knee when weight-bearing

Question 50

Surgery to remove meniscus can increase the contact pressure at the knee by 230% —> increase the risk of

Answer 50

stress-related osteoarthritis in the knee

Question 51

Meniscus tears in the red zone

Answer 51

can be repaired

Question 52

Meniscus tears in the white zone are usually

Answer 52

not repaired and sometimes require a meniscectomy