Knee

Question 1

What is the normal range of the internal angle of the knee?

Answer 1

185-190 // >190 = genu valga (knock knees) // <185 = genu vara (bow legged)

Question 2

Where does the mechanical axis of the knee lie?

Answer 2

It begins at the head of the femur and runs straight through femur and tibia

Question 3

Where does the anatomical axis of the knee lie?

Answer 3

It starts at the distal end of the neck of the femur and runs through the femur and tibia

Question 4

How much larger is the medial tibial plateau when compared to the lateral tibial plateau?

Answer 4

As much as 50%

Question 5

Lateral femoral condyle extends more in which direction?

Answer 5

Anteriorly

Question 6

The medial femoral condyle extends more in which direction?

Answer 6

Distally

Question 7

What is the closed pack position of the tibialfemoral joint?

Answer 7

Extension (and some external rotation)

Question 8

What is the open pack position of the tibialfemoral joint?

Answer 8

25-30* of flexion - where most injuries happen

Question 9

Genu Valgum increases the likelihood of OA on which side of the knees?

Answer 9

Lateral due to compression of lateral menisci/condyles

Question 10

What is genu recurvatum?

Answer 10

Hyperextension of the knees

Question 11

What are 3 possible causes of genu recurvatum?

Answer 11

Ligament laxity, weak quads, tight Achilles’ tendon

Question 12

How many bursa does the knee joint capsule contain?

Answer 12

3 - suprapatellar bursa, subgastroc bursa, and subpopliteal bursa

Question 13

Knee joint capsule fluid movement w/ extension

Answer 13

Moves from posterior to anterior and vice versa w/ flexion

Question 14

The prepatellar bursa is associated w/ what condition?

Answer 14

Housemaid’s knee

Question 15

Clergyman’s knee is associated with irritation of what bursa?

Answer 15

Superficial infrapatellar bursa

Question 16

Where are the cruciate ligaments generally located?

Answer 16

In the fibrous layer of the joint capsule, but extrasynovial

Question 17

LCL origin and insertion? Strengthened by what? Resists?

Answer 17

O: lateral femoral condyle
I: head of fibula

Strengthened by biceps femoris tendon

External rotation, becomes taut before MCL, this plays role in screw home mech
Also resists posterior displacement of tibia

Question 18

When is LCL most taut? Lax?

Answer 18

Most taut in extension, most lax in flexion

Question 19

MCL origin? Insertion?

Answer 19

O: medial aspect of medial femoral condyle
I: proximal tibia

Question 20

Why does MCL heal faster than LCL?

Answer 20

MCL partial attaches to medial meniscus, it is apart of the joint capsule and receives nutrients from synovial fluid as well as blood

Question 21

Posterior fibers of MCL orientation? Anterior fibers?

Answer 21

P: oblique
A: vertical

Question 22

ACL origin and insertion

Answer 22

O: anterior medial surface of tibia
I: posterior lateral surface of femur w/in intercondylar notch

Question 23

ACL comprised of 3 fibers

Answer 23

Anteromedial = most taut in flexion
Posterolateral = most taut in extension
Central

Question 24

ACL resists (3) facilitates (1)

Answer 24

Anterior displacement of tibia on femur
Internal rotation
Valgus and varus forces @ knee
Facilitates normal glide/roll of femur on tibia

Question 25

Terrible Triad

Answer 25

ACL, MCL, Meniscus

Question 26

ACL commonly injured in what position of knee?

Answer 26

ACL more commonly injured in extension, closed-chain exercises are recommended for rehab

Question 27

PCL origin, insertion, and bands?

Answer 27

O: posterior tibia in the intercondylar area (medial side of ACL) I: Anteromedial femur on lateral aspect of medial femoral condyle 2 bands: Anteromedial (taut in flexion) Posterolateral (taut in extension)

Question 28

PCL more commonly injured in what position of the knee?

Answer 28

Knee flexion (as opposed to ACL being more commonly injured in knee extension)

Question 29

PCL resists what motion(s)?

Answer 29

Posterior displacement of tibia on femur Internal rotation (especially at 90* of flexion) Valgus/varus forces Facilitates normal glide/roll

Question 30

PCL mech of injury

Answer 30

Forceful posterior translation of tibia - “dashboard injury”

Question 31

Oblique popliteal ligament origin and insertion + relation to popliteal fossa and artery

Answer 31

O: superior margin of intercondylar fossa of femur I: posterior medial tibial condyle Forms part of the floor of the popliteal fossa, popliteal artery rests on it

Question 32

Oblique popliteal ligament mech of injury

Answer 32

Dashboard injury, fall on fully flexed knee so tibia hits first - same as PCL = forceful posterior translation of the tibia

Question 33

Arcuate popliteal ligament origin and insertion

Answer 33

O:lateral posterior condyle of the femur I: head of fibula

Question 34

Ligaments of knee in flexion vs extension

Answer 34

Slack in flexion, taut in extension - screw home mech

Question 35

Knee joint stability -Posterior Static

Answer 35

PCL, Oblique Popliteal, Arcuate Popliteal

Question 36

Knee stability - Posterior Dynamic

Answer 36

Hamstrings, popliteus, gastrocnemius

Question 37

Knee Stability - Medial Static

Answer 37

MCL, PCL

Question 38

Knee stability - medial dynamic

Answer 38

Pens anserinus group (semitendinosis, gracilis, sartorious)

Question 39

Knee stability - anterior static

Answer 39

ACL, MCL, LCL

Question 40

Knee stability - anterior dynamic

Answer 40

quads, extensor retinacula

Question 41

Knee stability - lateral static

Answer 41

LCL, IT band

Question 42

knee stability - lateral dynamic

Answer 42

Biceps femoris // “not much”

Question 43

menisci function (5)

Answer 43

Shock absorber (reduces joint reaction force by 40-60% during activity) Increases articular surface area Stabilization Lubrication Proprioception

Question 44

Mechanism of injury for menisci

Answer 44

Axial rotation w foot planted - medial meniscus injured twice as much as lateral - Valgus force can make it worse, putting strain on MCL, posterior medial capsule and thus medial meniscus

Question 45

What ligaments connect the medial and lateral anterior horns of the menisci?

Answer 45

Anterior transverse ligament

Question 46

What ligaments root the menisci to their respective tibial plateaus?

Answer 46

Coronary (meniscotibial) ligaments

Question 47

External attachments of medial meniscus (4)

Answer 47

ACL MCL semimembranosis (pulls posteriorly during flexion) quads via meniscopatellar ligament (pulls anteriorly during extension)

Question 48

External attachments of lateral meniscus (3)

Answer 48

PCL Popliteus (pulls posterior during flexion) Quad via meniscopatellar ligament (pulls anterior during extension) **lateral meniscus most mobile**

Question 49

Which area of menisci endure the most stress/force?

Answer 49

Posterior horns

Question 50

Injuries to menisci (area and comparative likelihood)

Answer 50

Medial > lateral Posterior > rest

Question 51

How does ACL tear change osteokinematics of the knee?

Answer 51

More external rotation near full extension of the knee

Question 52

Axial rotation at the knee - internal vs external

Answer 52

2:1 external to internal

Question 53

Unlocking of screwhome mechanism involves? (Movement of bones/muscle?)

Answer 53

Either internal rotation of tibia on femur or external rotation of femur on tibia Activation of popliteus

Question 54

Why does LCL become taut before MCL when knee is extending?

Answer 54

LCL more posteriorly positioned

Question 55

Which artery supplies the ACL?

Answer 55

Middle genicular

Question 56

Which side of the patella is larger?

Answer 56

Lateral side - related to lateral femoral condyle extending more anteriorly

Question 57

Which side of the patella does the odd facet lie?

Answer 57

Medial side

Question 58

The patella increases moment arm for the quad group by what percentage?

Answer 58

50-60%

Question 59

Patellafemoral pain disorders arise from what?

Answer 59

Lack of articular cartilage

Question 60

Knee OA typically refers to which joint?

Answer 60

Tibiofemoral

Question 61

Patellar shift w flex/ext?

Answer 61

Sits laterally at the start and end ranges, moves slightly medial in the middle of the range

Question 62

Which direction is the articulating surface of the patella facing in ext? Flex?

Answer 62

Posteriorly in extension Superiorly in flexion

Question 63

What is circumferential displacement?

Answer 63

Term to describe the direction the articulating surface of the patella faces in flex, ext: Faces posteriorly in extension Faces superiorly in flexion

Question 64

What does the articularis genu serve to do in relation to the suprapatellar bursa?

Answer 64

Pulls Suprapatellar bursa anteriorly to prevent it being pinched between femur and patella when the knee is moving from flexion into extension

Question 65

The ________ surface of the patella articulates on the _______ surface of the femoral condyles in extension

Answer 65

INFERIOR surface of the patella articulates on the SUPERIOR surface of the femoral condyles And vice versa as the knee moves into flexion

Question 66

Proper alignment of the patella during movement is determined by (4)

Answer 66

Vastus lateralis, medialis Lateral and medial retinaculum

Question 67

Patellar stabilization (static?) (6)

Answer 67

Medial and lateral patellotibial ligaments Medial and lateral patellofemoral ligaments Medial and lateral retinacula

Question 68

Patellofemoral disorders can typically lead to?

Answer 68

Disactiviation of quads

Question 69

Q-angle definition, norm value?

Answer 69

Measurement of lateral line of pull of quads relative to the patella 15*

Question 70

Abnormal Q-angle?

Answer 70

Greater than or equal to 20* = increased lateral pull of patella

Question 71

Capsular pattern for knee

Answer 71

Greater loss of flexion