The Knee joint

Question 1

What are acute injuries to the knee caused by and where do they usually present to?

Answer 1

• sports
• falls
• elderly
• fracture
• tear/sprain of ligaments
• soft tissues
• cartilage

Question 2

What causes acute swelling/ pain?

Answer 2

• atraumatic causes
• acute gout
• flare of Osteo-arthritis
• flare of RA

Question 3

What causes chronic knee pain/ swelling?

Answer 3

• osteoarthritis

- bursitis

Question 4

What can severe knee pain result in?

Answer 4

reduced mobility

poor sleep

reduced quality of life

Question 5

How does chronic knee pain/swelling have to last for in order for it to be classified as chronic?

Answer 5

3-4 months to 1 year

Question 6

What is not associated with the knee joint?

Answer 6

fibula

Question 7

What type of joint is the knee joint?

Answer 7

hinge joint

synovial

Question 8

What 3 bones are involved in the knee joint?

Answer 8

1. distal femur
2. proximal tibia
3. patella

Question 9

How many articulations do the 3 bones involved in the knee joint form?

Answer 9

3 articulations

Question 10

What are the 3 articulations formed in the knee joint?

Answer 10

• 2 femorotibial - medial and lateral

- 1 femoropatellar

Question 11

What is the most proximal part of the tibia like?

Answer 11

flat

Question 12

What are the movements of the knee joint?

Answer 12

• extension/ flexion

- medial/lateral rotation - only a very small amount of rotation

Question 13

Why do you lose knee flexion when the hip is extended?

Answer 13

due to the loss of tension on hamstrings

Question 14

When can rotation occur?

Answer 14

when knee is flexed and collateral ligaments are relaxed

Question 15

What happens when the knee joint approaches full extension?

Answer 15

the femur undergoes a few degrees of medial rotation on the tibia

this is also known as locking

Question 16

What is locking?

Answer 16

joint approaching full extension and causing the femur to undergo a few degrees of medial rotation on the tibia

Question 17

Is locking the knee stable or unstable and why is it so?

Answer 17

it is stable - as thigh muscles can relax

Question 18

How is the knee unlocked?

Answer 18

By the popliteus muscle

Question 19

What does the popliteus muscle do to the femur?

Answer 19

it laterally rotates the femur

Question 20

Where and what is the popliteal fossa?

Answer 20

The space at the back of the knee

Question 21

What runs through the popliteal fossa?

Answer 21

the popliteal artery

Question 22

What are the medial and lateral femoral condyles?

Answer 22

expanded ends of the femur

Question 23

What are the slight expansions of the proximal tibia?

Answer 23

medial and lateral tibial condyles

Question 24

What is the flat surface of the tibia above the condyles known as?

Answer 24

tibial plateau - medial and lateral

Question 25

What is the fit like of the tibial plateau with the rounded femoral condyles and what is the joint described as?

Answer 25

poor fit incongruent

Question 26

What is the tibial plateaux deepened by?

Answer 26

- 2 plates of fibrocartilage | - the menisci

Question 27

What is stability and congruency like in extension?

Answer 27

most stable very congruent

Question 28

What is stability and congruency like in flexion?

Answer 28

unstable least congruent

Question 29

What are the menisci?

Answer 29

2 c shaped wedges of fibrocartilage

Question 30

Where are the menisci thicker?

Answer 30

at the external margins

Question 31

What are the functions of the menisci?

Answer 31

- increase joint congruency - distribute weight evenly - shock absorption - assist in locking mechanism

Question 32

What do the external edges of the menisci attach to?

Answer 32

fibrous capsule of the joint

Question 33

What is the medial meniscus firmly attached to?

Answer 33

the tibial collateral ligament

Question 34

What can cause meniscal tears?

Answer 34

sports or degenerative changes

Question 35

What can cause pain or locking in meniscal tears?

Answer 35

displaced cartilage becoming trapped during knee movements

Question 36

What is the treatment of meniscal tears?

Answer 36

repair or resection

Question 37

What arthritis is damage of the meniscus associated with?

Answer 37

osetoarthritis

Question 38

Why is the meniscus not very good at repairing itself?

Answer 38

as there is decreased blood supply

Question 39

What are the different types of meniscal tears? (6)

Answer 39

1. vertical 2. transverse 3. peripheral 4. bucket handle 5. parrot beak 6. flap

Question 40

What contribute to the stability of the knee?

Answer 40

ligaments muscles - surrounding (most important part of the knee)

Question 41

What are the ligaments inside the joint/ intra-articular ligaments?

Answer 41

anterior and posterior cruciate ligaments

Question 42

What are the ligaments outside the joint/ extra articular ligaments?

Answer 42

fibular and tibial collateral ligaments they work down on each side of joint

Question 43

Where are the cruciate ligaments?

Answer 43

inside the joint capsule

Question 44

how do the cruciate ligaments cross each in the centre of the knee?

Answer 44

obliquely

Question 45

What does the posterior cruciate ligament attach to?

Answer 45

posterior intercondylar region of the tibia

Question 46

Where does the posterior cruciate ligament travel?

Answer 46

supero-anteriorly to insert onto the medial femoral condyle

Question 47

What does the anterior cruciate ligament attach to?

Answer 47

anterior intercondyle region of the tibia

Question 48

How does the anterior cruciate ligament travel?

Answer 48

supero-posteriorly to attach to the lateral femoral condyle

Question 49

Which is the stronger cruciate ligament?

Answer 49

Posterior cruciate ligament

Question 50

What does the posterior cruciate ligament prevent?

Answer 50

posterior displacement of the tibia of the femur hyperflexion

Question 51

Which cruciate ligament is the main stabiliser of the flexed knee when weigh bearing?

Answer 51

posterior cruciate ligament

Question 52

How can the posterior cruciate ligament be damaged?

Answer 52

When landing on the tibial tuberosity with the knee flexed - tibia slides backwards

Question 53

What does the anterior cruciate ligament prevent?

Answer 53

anterior displacement of the tibia on the femur hyperextension

Question 54

How can the anterior cruciate ligament be damaged? (2)

Answer 54

when knee is hyperextended to force is applied anteriorly

Question 55

Which cruciate ligament is more commonly injured?

Answer 55

anterior cruciate ligament

Question 56

What is the tibial/medial collateral ligament?

Answer 56

a flat band attached to the medial meniscus

Question 57

What does the tibial/medial collateral ligament prevent?

Answer 57

prevents abduction of the at the knee

Question 58

What is the fibular/ lateral collateral ligament?

Answer 58

cord like band not attached to the lateral meniscus

Question 59

What does the fibular/ lateral collateral ligament prevent?

Answer 59

prevents adduction of the leg at the knee

Question 60

How does the lateral and medial collateral ligaments provide stability to the knee?

Answer 60

they prevent rotation during extension

Question 61

What is a combined knee injury also known as?

Answer 61

the unhappy triad

Question 62

What is a combined knee injury caused by?

Answer 62

excessive lateral twisting of the flexed knee blow to the lateral side of the extended knee

Question 63

What is torn in a combined knee injury?

Answer 63

tibial collateral ligament which is attached to the medial meniscus - which also tears anterior cruciate ligament may also tear as it is taut during flexion (common when flexed knees are twisted)

Question 64

What muscles are important in relation to the knee joint and act as the main stabilisers of the knee? (5)

Answer 64

1. quadriceps 2. hamstrings - posterior thigh 3. sartorius 4. gracillis 5. illiotibial tract

Question 65

What can compensate for ligament damage and avoid surgery?

Answer 65

building up quads through physio and exercise - cycling

Question 66

What are two bursae you need to be aware of?

Answer 66

prepatellar bursa suprapatellar bursa

Question 67

What problems can occur with the bursae and who is more prone to getting them?

Answer 67

1. prepatellar bursitis 2. suprapatellar effusion people who spend a lot of time on their knees

Question 68

What are common bony fractures to the knee? (3)

Answer 68

Fractures to: 1. patella 2. tibia 3. distal femur

Question 69

What and where are the causes of the common bony fractures to the knee?

Answer 69

- trauma - osteoporotic bone - low energy fractures - peri-prosthetic - fractures around joint replacements

Question 70

What are common meniscal tear causes?

Answer 70

1. acute injury/ trauma | 2. wear and tear

Question 71

What are causes of ligamentous injuries to the knee?

Answer 71

- trauma

Question 72

What injuries usually happen to the ligaments of the knee?

Answer 72

- tears and rupture

Question 73

What are common dislocations?

Answer 73

- patella - more common in females - whole knee joint - very uncommon - acute injury/ trauma

Question 74

What direction do patella dislocations occur?

Answer 74

laterally due to placement and alignment of the knee

Question 75

What direction does the rectus femurs, vastus intermedius and vast us lateralis pull?

Answer 75

superolaterally

Question 76

What are the rectus femurs, vast us intermedius and vastus lateralis counteracted by?

Answer 76

the horizontal pull of the vast us medial is

Question 77

Why is patella dislocation more common in females?

Answer 77

ankle of the neck of the femur is different and therefore the angle of placement is bigger (Q angle)

Question 78

What is the dislocation of the patella related to?

Answer 78

the alignment of the femur in relation to the tibia

Question 79

What are examples of abnormal alignment of the femur in relation to the tibia?

Answer 79

1. genu varum | 2. genu algum

Question 80

What is genu varum?

Answer 80

tibia is adducted wither respect to femur - bow leg

Question 81

What is genu valgum?

Answer 81

Tibia abducted with respect to femur

Question 82

What changes are apparent in osteoarthritis?

Answer 82

- osetophytes - scleorosis - abnormal density of bone - reduced joint space - very little meniscus

Question 83

What does abnormal alignment of the knee lead to?

Answer 83

abnormal loading around the knee

Question 84

What is a characteristic feature of a patellar fracture?

Answer 84

rough jagged ends

Question 85

What shouldn't you confuse a patellar fracture with?

Answer 85

bi-partite patellar - no jagged ends

Question 86

What is a characteristic of a femoral fracture?

Answer 86

painful - shards of bone

Question 87

How much force is required for a tibial plateau fracture?

Answer 87

- a lot | - can be subtle and can be easily missed

Question 88

What tears in a complete knee dislocation?

Answer 88

cruciate ligaments - connecting the tibia to the femur

Question 89

What would you worry about in complete knee dislocation?

Answer 89

damage to blood supply and nerve supply (popliteal artery and nerve)