Session 9 - The Knee joint

Question 1

What are the articulations in the knee joint?

Answer 1

• Tibial plateau
• Condyles of femur
• Patella

Question 2

Which condyle of the femur is larger and why?

Answer 2

• Medial

- Takes more weight

Question 3

Why is there an anterior shallow depression on the distal femur?

Answer 3

-Where patella articulates

Question 4

Where is the intercondylar fossa?

Answer 4

-Posterior deep notch of the femur between the condyles

Question 5

Which epicondyle of the femur has the adductor tubercle?

Answer 5

-Medial

Question 6

What ligaments attach to the epicondyles of the femur?

Answer 6

-Collateral ligaments

Question 7

What do the condyles of the tibia form? Describe the surface of this

Answer 7

• Tibial plateau
• Medial surface slightly concave superiorly
• Lateral surface slightly convex superiorly
• Raised and rough areas known as the intercondylar eminence separate the two sides

Question 8

What bony landmark lies within the tibial plateau?

Answer 8

-Intercondylar eminence

Question 9

What attaches to the intercondylar eminence?

Answer 9

-Cruciate ligaments

Question 10

What are menisci?

Answer 10

-Wedge-shaped circular fibrocartilaginous bands which cover the articular surface of the tibia

Question 11

What is the function of menisci?

Answer 11

• Deepen the articular surface of tibial element
• Provide stabilisation and support
• Act as shock absorbers

Question 12

How many menisci are there?

Answer 12

-2 (one medial one lateral)

Question 13

How are the menisci attached at the knee?

Answer 13

• Attached to the intercondylar eminence and to the joint capsule via coronary ligaments
• Attached to each other anteriorly by the transverse ligament of the knee

Question 14

What factors stabilise the knee joint?

Answer 14

• Menisci
• Muscles (Quadriceps femoris/iliotibial tract)
• Ligaments

Question 15

What are the intracapsular ligaments which stabilise the knee?

Answer 15

-Anterior and posterior cruciate ligaments

Question 16

Where does the anterior cruciate ligament attach?

Answer 16

-Anterior tibia, posterior femur

Question 17

-What is the function of the anterior cruciate ligament?

Answer 17

• Prevents tibia moving anteriorly/femur moving posteriorly

- Limits hyperextension

Question 18

Which is the weaker cruciate ligament?

Answer 18

-Anterior

Question 19

Where is the posterior cruciate ligament attached?

Answer 19

-Posterior tibia

Question 20

What is the function of the posterior cruciate ligaments?

Answer 20

• Stops tibia moving posteriorly, femur moving anteriorly

- Limits hyperflexion

Question 21

What is a pneumonic to remember cruciate ligaments?

Answer 21

-PAMs APLles
Posterior moves Anteriorly and inserts Medially
Anterior moves Posteriorly and inserts Laterally

Question 22

What are the main extracapsular ligaments of the knee?

Answer 22

-Medial and lateral collateral ligaments

Question 23

Where does the medial collateral ligament inserts and attach?

Answer 23

• Extends from medial epicondyle of femur
• Inserts into medial condyle of tibia
• Attaches to medial meniscus

Question 24

Which collateral ligament blends with the joint capsule and which is separate?

Answer 24

• Lateral is separate

- Medial blends

Question 25

Where does the lateral collateral ligament attach?

Answer 25

-Lateral fibular head

Question 26

Except cruciates and collaterals, what other ligaments are involved in the knee joint?

Answer 26

- Patella ligament | - Oblique and Arcuate popliteal ligaments

Question 27

What is the function of the popliteal ligaments?

Answer 27

-Re-enforce joint laterally

Question 28

Which muscles extend the knee joint?

Answer 28

-Quadriceps femoris

Question 29

Which muscles flex the knee joint?

Answer 29

- Sartorius - Gracilis - Hamstrings - Gastronemius - Plantaris

Question 30

What muscles internally/medially rotate the knee?

Answer 30

- Semitendinosus - Sartorius - Gracilis - Semimembranosus

Question 31

Which muscles externally rotate the knee?

Answer 31

-Biceps femoris

Question 32

Which muscles make the hamstrings?

Answer 32

- Biceps femoris (long head and short head) - Semimembranosus - Semitendinosus - Part of adductor magnus

Question 33

Where do the hamstrings attach at the pelvis?

Answer 33

-Ischial tuberosity

Question 34

What nerve innervates the hamstrings?

Answer 34

-Tibial (except short head biceps femoris-> common fibular)

Question 35

When is the posterior cruciate ligament most often damaged?

Answer 35

-Falling on tibial tuberosity with flexed knee

Question 36

How is the posterior cruciate ligament tested?

Answer 36

-Posterior draw test

Question 37

When is the anterior cruciate ligament most commonly damaged?

Answer 37

-during hyperextension

Question 38

How is the anterior cruciate ligament tested?

Answer 38

-Anterior draw test

Question 39

Why is the lateral menisci usually undamaged?

Answer 39

-It is mobile

Question 40

Why do menisci usually heal well?

Answer 40

-They have a good blood supply

Question 41

What is the unhappy triad?

Answer 41

-Damage to medial collateral ligament, medial meniscus and anterior cruciate ligament

Question 42

Why is the medial meniscus usually damaged in medial collateral ligament damage?

Answer 42

-They are firmly attached together

Question 43

When does the unhappy triad usually occur in knee injuries?

Answer 43

- Lateral twisting of flexed knee | - Blow to the side of the knee

Question 44

What type of arthritis is most common in the knee?

Answer 44

-Osteoarthritis

Question 45

Which bursa are the most commonly effected by bursitis in the knee?

Answer 45

- Supra-patella - Pre-patella - Superficial infra-patella

Question 46

What is the laymans term for pre-patella bursitis?

Answer 46

-Housemaids knee

Question 47

What is the laymans term for infra-patella bursitis?

Answer 47

-Clergyman's knee

Question 48

What is a popliteal cyst?

Answer 48

-Abnormal fluid filled sacks of synovial membrane in the popliteal fossa

Question 49

What is a differential diagnosis of popliteal cyst?

Answer 49

-Popliteal artery aneurysm

Question 50

How are knee injuries most commonly investigated?

Answer 50

- Plain film x-ray - MRI - Clinical examination - Aspiration - Arthroscopy

Question 51

Why does the knee joint require extra things for stabilisation?

Answer 51

-The tibial plateau and the condyles of the femur are a mismatch of shapes

Question 52

Why is the lateral menisci more mobile than the medial?

Answer 52

-Its points of attachment at the eminence are closer to each other allowing for mor movement

Question 53

What are the most important muscles of quadriceps femoris in stabilising the knee?

Answer 53

- Vastus lateralis | - Vastus medialis

Question 54

What re-enforces the ligaments of the lateral knee?

Answer 54

-Ilio-tibial tract

Question 55

The oblique popliteal ligament is an extension of...

Answer 55

...tendon of semimembranosis

Question 56

Why and how does the knee lock during extension?

Answer 56

- Makes it easier to stand | - Femur rotates slightly internally over tibia and the knee joint can be held in position

Question 57

What muscle helps to 'unlock' the femur?

Answer 57

-Popliteus helps to rotate the femur externally

Question 58

With what injuries are the menisci usually damaged?

Answer 58

-Medial collateral or anterior cruciate ligament injury

Question 59

What is the most common cause of bursitis?

Answer 59

- Chronic friction | - Direct trauma

Question 60

Which bones are involved in the knee joint?

Answer 60

- Femur - Tibia - Patella

Question 61

Describe the blood supply to the knee

Answer 61

- complex genicular anastamoses around the knee | - popliteal artery runs through popliteal fossa