Lecture 7A

Question 1

The _____ tibial plateau is smaller and more mobile than the _____ tibial plateau

Answer 1

Lateral

Medial

Question 2

The _____ joint is dependent on BOTH dynamic and static restraints for function and stability

Answer 2

Patello-femoral joint

Question 3

Patello-Femoral Joint (4) Functions?

Answer 3

1. Provide articulation with low friction
2. Protect distal femur and quad tendon from damage/wear
3. Improve movement arm of quad mm. to increase efficiency
4. Decrease amount of AP shear stress placed on tib-fem joint

Question 4

Which menisci is more C-shaped?

which is more O-shaped?

Answer 4

Medial

Lateral

Question 5

What are the 3 big purposes of menisci?

Answer 5

1. Stability
2. Shock Absorption
3. Lubrication

Question 6

How much of the load does the menisci transmit in knee extension?

In knee flexion?

Answer 6

50-70%

85-90%

Question 7

What part of the menisci has the best innervation and nutrition?

Answer 7

Outer 1/3 and anterior and posterior horns

Question 8

How do nutrients get into the mensicus?

Answer 8

Movement

injuries often occur due to lack of movement

Question 9

The anteriomedial bundle of the ACL is taut in

Answer 9

flexion

Question 10

the ACL posteriolateral bundle is taut in _______

Answer 10

extension

Question 11

What are the 3 motions that the ACL prevents?

Answer 11

anterior tibial translation

posterior femoral translation

Internal tibial rotation

Question 12

What motions does the PCL stop (4)?

Answer 12

Posterior tibial translation

anterior femur translation

internal tibial rotation

secondary restraint to valgus and varus forces

Question 13

____ knee flexion isolates the MCL

Answer 13

25-30 degrees of knee flexion

Question 14

the MCL resists what

Answer 14

valgus stress

Question 16

the mcl and lcl also resist _______ rotation

Answer 16

tibial external rotation

Question 17

Which liagment blends with the joint capsule: MCL or LCL

Answer 17

MCL

Question 18

LCL resists varus forces especially at _______

Answer 18

35 degrees flexion

Question 19

Anterior vs Posterior joint capsule reinforcement

Answer 19

Anterior- Quad + Patella retinaculum

Posterior - OPL + Popliteus + Gastroc + hamstrings + posterior arcuate complex

Question 20

What muscles support the medial joint capsule?

What muscles support the lateral joint capsule?

Answer 20

medial- muscles at pes anserinus

Lateral- Biceps femoris + popliteus + lateral head of gastroc

Question 21

What is the hoffman’s fat pad

Answer 21

source of anterior knee pain, it gets stuck and increases joint compression.

Question 22

What % of the population have a plica, where is it located

Answer 22

20-60%

loose synovial fold from fetal development medial patella

Question 23

What is the MOI of plica syndrome

Answer 23

Repetitive knee flexion

Question 24

What is the open packed position of the knee?

Closed packed?

Answer 24

25 flexion

Extension

Question 25

Open chain rolling and gliding of knee:

Answer 25

Same direction Concave on convex Tibia on femur

Question 26

Close chain rolling and gliding of knee

Answer 26

Opposite Convex on concave Femur on tibia

Question 27

What is the action of the poplitues muscle

Answer 27

UNLOCKS knee knee with tibial internal rotation

Question 28

What are the 3 causes of the screw home mechanism (locking)

Answer 28

Shape of medial femoral condyle Passive tension of ACL Lateral pull of quadriceps

Question 29

What is the normal q angle

Answer 29

Long axis of femur vs long axis of tibia 13-18.

Question 30

Increased Q angle is associated with Femoral ____version ______ tibial torsion Laterally displaced tibial tubercle Genu Valgum

Answer 30

Femoral anteversion external tibial torsion

Question 31

Genu Valgum compressed the _____ condyles Genu varum compressed the ___ condyles

Answer 31

Lateral Medial

Question 32

What is the open packed position of the patellofemoral joint Close packed?

Answer 32

Full ext Full flexion

Question 33

Flat lateral femoral condyles lead to

Answer 33

More common patellar subluxation

Question 34

How much does the patella normally move

Answer 34

7-8cm in relation to femoral condyles

Question 35

4 functions of patello-femoral joint

Answer 35

Pulley Guides quad tendon Decrease friction Shields cartilage of femoral condyles

Question 36

What are 3 reasons why the patella can track laterally

Answer 36

Vastus lateralis stronger than medial Lateral patellar retinaculum tight Short IT band Deficits in lateral intercondylar groove

Question 37

There is a deficit of the lateral aspect of the intercondylar groove if the sulcus angle is ____

Answer 37

Greater than 150

Question 38

Knee ext: proximal fibula moves ______ Knee flexion: proximal fibula moves ____

Answer 38

posterior Anterior

Question 39

How does the proximal fibula move during ankle Dorsi

Answer 39

Externally rotates and moves slightly up

Question 40

What kind of joint is the proximal tibia-fibular joint

Answer 40

Plane synovial joint

Question 41

Is the proximal tibia fibular joint inside or outside of the joint capsule

Answer 41

Outside