Knee

Question 1

Explain the knee (tibiofemoral) jt

Answer 1

Modified hinge between the femur, patella, and tibia

Question 2

Tibiofemoral alignment: the femoral shaft is _____________ lateral from the tibial shaft. Resulting in..

Answer 2

170/175*

Slight physiological valgus

Question 3

Describe Knock-knees

Answer 3

Excessive genu valgus ( less than 165*)

Question 4

Describe bow legs

Answer 4

Genu valgus

Greater than 180*

Question 5

The ________ compartment of the knee accepts greater compressive force during genu varum. Which could result in..

Answer 5

Medial

OA in that area

Question 6

Increased Lateral compression force in the knee could be a result of ____________

Answer 6

Genu valgum

Question 7

Increased stress on MCL, increased stress in lateral compartment, Excessive lateral tracking of the patella, and Increased stress on ACL can be a result from

Answer 7

Genu valgum

Question 8

Increased medial compartment loading, Greater loss of medial joint space, and Increased strain on LCL could be a result of

Answer 8

Genu varum

Question 9

Genu recurvatum can occur secondary to

Answer 9

Laxity of posterior knee structure (posterior capsule and knee flexors)

Or

Overpowering knee extension torque

Question 10

Meniscus functions in the knee

Answer 10

Distribute wt bearing forces
Increase jt congruence
Shock absorption

Question 11

Which meniscus of the knee is less mobile

Answer 11

Medial meniscus, due to greater ligament restraint

Question 12

The medial meniscus has connections to the

Answer 12

MCL, ACL, PCL, and semimembranosus

Question 13

The lateral meniscus has connections to the

Answer 13

ACL, PCL, and popliteus

Question 14

Menisci of the knee are vascularized ______ and diffuse synovium ________

Answer 14

Peripherally

Centrally

Question 15

The menisci increase _____________ and reduce _________

Answer 15

Contact area

Reduce jt stress

Question 16

Which crucible lig. Resists anterior translation of the tibia, hyperextnsion, varus and valgus stretches, and tibial rotation?

Answer 16

Anterior cruciate lig

Question 17

Functions of the PCL

Answer 17

restrains posterior translation of the tibia, varus and valgus stretch and tibial rotation medially

Question 18

What is the primary restrains to valgus force and lateral tibial rotation

Answer 18

Medial collateral lig

Question 19

What is the primary restraint to varus stretch, and also restrains lateral tibial rotation?

Answer 19

Lateral collateral lig

Question 20

Function of the iliotibial tract

Answer 20

Assists ACL in resisting anterior translation of tibia on femur

Question 21

3 factors associated with non-contact injuries

Answer 21

Strong activation of quad over moderately flexed or nearly extended knee

Marked valgus collapse of the knee

Excessive ER of the knee

Question 22

Common MOI for ACL tear

Answer 22

Excessive hyperextension with foot firmly planted

Question 23

MOI of PCL tear

Answer 23

Falling on to fully flexed knee with ankle plantar flexed (proximal tibia his ground first)
“Dashboard” injury

Usually high energy trauma

Question 24

Posterior sag sign

Answer 24

Tibia sags posterior in hook lying.

Shows PCL is not in tact

Question 25

Tibiofemoral Osteokinematics

Answer 25

Flex/ext IR/ER ABD/ADD accessory mvmts

Question 26

Arthrokinematics of flexion in the tibiofemoral jt OKC and CKC

Answer 26

OKC: posterior roll and glide CKC: posterior roll anterior glide

Question 27

Arthrokinematics of extension at the tibiofemoral jt OKC & CKC

Answer 27

OKC: anterior roll and glide CKC: anterior roll and posterior glide

Question 28

Screw home mechanism

Answer 28

ER with terminal extension Knee needs 10 deg of er to fully ext, usually in the last 5 deg of ext

Question 29

To unlock the knee from full ext, the ______________ bust _________________ the knee to perform flexion

Answer 29

Popliteus | Medially rotate

Question 30

Closed packed position of the tibiofemoral jt

Answer 30

Full ext

Question 31

Open packed position of tibiofemoral jt

Answer 31

25 deg of flexion

Question 32

Capsular pattern of the tibiofemoral jt

Answer 32

Flexion>> ext

Question 33

The patella functions as a ________ for the quad

Answer 33

Pulley

Question 34

Ability of the patella to function appropriately is dependent on

Answer 34

Patellar mobility

Question 35

During full extension, the patella lies on the _____________________ . The minimal congruency in this position results in …

Answer 35

Femoral sulcus Greater chance for instability near full extension

Question 36

Patellofemoral pain syndrome

Answer 36

Less than optimal congruency or subtle structural anomalies of the PF joint likely results in abnormal “tracking” of the patella causing pain

Question 37

Patellofemoral Passive Structures

Answer 37

``` Lateral patellofemoral ligament Medial patellofemoral ligament Medial patellotibial ligament Lateral patellotibial ligament Quadriceps ```

Question 38

Function of the patella

Answer 38

Increases the internal moment arm> increasing mechanical advantage > increases extension torque

Question 39

Knee extensor moment arm is greatest btw

Answer 39

20-60 deg of knee flex

Question 40

Sup/inf glide at the patellofemoral jt is present in what motions

Answer 40

Flex/ext

Question 41

Medial and lateral shift of the patellofenoral jt is described as

Answer 41

Frontal plane translation

Question 42

During medial/lateral tilt, the patella….

Answer 42

Rotates around the vertical axis

Question 43

During Medial and lateral rotation at the patellofemoral jt, the patella…

Answer 43

Rotates around the a/p axis

Question 44

Q-angle

Answer 44

Angle formed between: Line connecting ASIS to middle of patella Line connecting tibial tuberosity to middle of patella Estimation of the line of pull of quadriceps

Question 45

Increased Q angle increases…

Answer 45

Lat force on the patella

Question 46

Normal Q angle

Answer 46

13-15 deg

Question 47

Structures that oppose lateral pull of the patella

Answer 47

Raised lateral facet of trochlear groove Quadriceps – particularly the VMO Medial patellar retinacular fibers Medial passive structures

Question 48

The PF jt is exposed to high loads of compressive force during what activities

Answer 48

1. 3x body weight with walking on level surfaces 2. 6x body weight with SLR 3. 3x body weight climbing stairs 7. 8x body weight with deep squats

Question 49

The quads product the greatest torque in a seated leg ext between…

Answer 49

45- 0 deg of ext

Question 50

The quads produce the greatest torque during a squat between…

Answer 50

45- 90 deg of knee flex

Question 51

Qualities of a stiff landing

Answer 51

Unsafe landing pattern Larger knee EMA Smaller hip EMA Note high activation of quad

Question 52

Qualities of a safe landing

Answer 52

Smaller knee EMA Larger hip EMA Increased hamstring-to-quad contraction pattern