Knee

Question 1

T or F: The patella is the largest sesamoid bone in the body

Answer 1

True

Question 2

Functions of the patella (5)

Answer 2

• Increase internal moment arm of the quadriceps
• Centralize force of quadriceps pull
• Reduce tendon friction forces
• Contribute to overall knee stability
• Provide bony protection

Question 3

The tibiofemoral joint is the largest or smallest joint in the body?

Answer 3

Largest

Question 4

Tibiofemoral joint DOF

Answer 4

2 DOF

• flex/ex
• IR/ER

Question 5

Tibiofemoral lateral menisci

• shape
• mobility

Answer 5

oval shaped; considerable mobilty

Question 6

Tibiofemoral medial menisci

• shape
• mobility

Answer 6

C shaped; not as mobile as lateral meniscus

Question 7

Tibiofemoral menisci attachments (7)

Answer 7

• coronary ligaments (attach to tibia)
• transverse ligament (anterior horns)
• meniscopatellar fibres
• deep medial collateral ligament
• semimembranosus (attaches to posterior/medial mensicus)
• popliteus attachment (lateral meniscus)
• meniscofemoral ligaments (lateral meniscus)

Question 8

Tibiofemoral meniscus functions

Answer 8

• deepens socket and improve congruency
• absorb and distribute forces/ increase surface area
• promote lubrication of joint
• prevent joint capsule from intruding into joint space
• partially protect against excessive motion

Question 9

Tibiofemoral collateral ligament

• function
• capsule?

Answer 9

• provide medial and lateral stabilty

- extracapsular

Question 10

T or F: The MCL and LCL provide more protective force in flexion than extension

Answer 10

True

Question 11

Tibiofemoral anterior cruciate ligament

- function

Answer 11

• resists anterior translation of the tibia and reverse (posterior glide of femur on tibia)

Question 12

Tibiofemoral posterior cruciate ligament

- function

Answer 12

• resists posterior translation of the tibia on the femur or reverse (anterior translation of femur on tibia)

Question 13

Tibiofemoral osteokinematics

Answer 13

• flex/ex, soft tissue end feel/ firm end feel

- axial rotation, firm end feel

Question 14

Instantaneous centre of rotation

Answer 14

• femoral condyles are larger than tibial condyles

- centre of motion changes as the knee flexes and extends

Question 15

Which muscle unlocks the fully extended knee?

Answer 15

Popliteus

Question 16

Screw home mechanism

Answer 16

• during the last 20 degrees of extension

- with OKC lateral tibial compartment finished excursion before medial tibial compartment

Question 17

The tibia locks down in an OKC or CKC

Answer 17

OKC

Question 18

The femur locks down in an OKC or CKC

Answer 18

CKC

Question 19

T or F: in CKC extension, the femur rotates medially on the fixed tibia

Answer 19

True

Question 20

Tibiofemoral close packed position

Answer 20

Full extension

Question 21

Tibiofemoral resting position

Answer 21

25 degrees knee flexion

Question 22

Patellofemoral joint

• articulations
• tissues
• kinematics (OKC, CKC)

Answer 22

• posterior surface of patella and anterior/distal aspect of femur
• retinaculum, vastus medialis oblique, patellar tendon
• OKC: patella moves on femur
• CKC: femur moves on patella

Question 23

Maximum contact of the patella and the femur occurs at ___ degrees of flexion

Answer 23

90

Question 24

Patellofemoral close packed position

Answer 24

Full flexion

Question 25

Patellofemoral resting position

Answer 25

Full extension

Question 26

As knee flexes, the patella moves inferiorly or superiorly

Answer 26

Inferiorly

Question 27

Patellofemoral Q angle

Answer 27

- measured from ASIS and patella/tibial tuberosity

Question 28

Extensor muscles of the knee

Answer 28

``` Vastus lateralis Vastus medialis Vastus intermedius Rectus Femoris Articularis Genu ```

Question 29

Which of the knee extensors is the largest?

Answer 29

Vastus lateralis

Question 30

Knee flexors

Answer 30

``` Hamstring group Gracilis Sartorius Plantaris (little role) Popliteus ```

Question 31

Tibial medial rotators

Answer 31

Semimembranosus Semitendinosus Gracilis Popliteus

Question 32

Knee flexion and hip extension: which muscle are in active and passive insufficiency?

Answer 32

Hamstrings: active insufficiency | Rectus femoris: passive insufficiency

Question 33

Knee extension with hip flexion: which muscles are in active and passive insufficient?

Answer 33

Hamstrings: passive insufficiency | Rectus femoris: active insufficiency

Question 34

Knee flexion with hip flexion: active sufficiency or passive sufficiency?

Answer 34

Hamstrings are in active sufficiency, elongated at hip and shortened at knee Rectus femoris is in active sufficiency, elongated at knee and shortened at hip

Question 35

Knee flexion with plantar flexion: which muscle is in active insufficiency?

Answer 35

Gastrocnemius

Question 36

When is gastrocnemius in active sufficiency?

Answer 36

- plantar flexed foot and extended knee | - dorsiflexed foot and flexed knee

Question 37

In a unilateral stance, the line of gravity medial?/lateral? to tibiofemoral joint

Answer 37

medial, takes 60% of forces