The knee

Question 1

What are the 3 articulations in the knee joint?

Answer 1

1. lateral femoral and tibial condyles with corresponding meniscus 2. medial femoral and tibial condyles with corresponding meniscus 3. patella and femur

Question 2

What type of joint is the knee joint? What is its action?

Answer 2

Hinge joint Extension and flextion

Question 3

What is the stability of the knee joint dependant on?

Answer 3

1. Strength and actions of surrounding muscles and their tendons 2. The ligaments that connect the femur and tibia

Question 4

Position of tibia and femur within the thigh and leg?

Answer 4

The femur is positioned diagonally within the thigh The tibia is almost vertical

Question 5

What is the Q line and Q angle? What is it in men and women?

Answer 5

Line drawn from ASIS to central patella Central patella to ischeal tuberosity Males approx 14o (+/- 3) Females approx 17o (+/- 3)

Question 6

What happens when the Q angle increases?

Answer 6

• Genu valgum
• Patella subluxation (dislocation)

Question 7

Why are women at greater risk of pain and injury?

Answer 7

• Pelvis wider so hip joints further lateral
• Femurs have to angle more to medial side to carry body weight
• Medial side of knee carrying more weight

Question 8

Name the articular ligaments in the knee. What is there function?

Answer 8

• medial and lateral collateral ligaments (tibial and fibular collateral ligament)
• anterior and posterior cruciate ligaments
• patella ligament (patella tendon)
• articular capsule

Stabilise the knee

Question 9

Describe features of Medial collateral ligament

Answer 9

• Broad flat ligament
• Thickening of joint capsule, attached to medial meniscus.
• Taut in knee extension - prevents knee abduction

Question 10

Which ligament prevents knee abduction

Answer 10

Medial collateral ligament (tibial)

Question 11

Describe features of the Lateral collateral ligament (fibular)

Answer 11

• Strong fibrous cord.
• Not attached to joint capsule or lateral meniscus.
• Taut in knee extension -prevents knee adduction

Question 12

Which ligament prevents knee adduction

Answer 12

Lateral collateral ligament (fibular)

Question 13

Describe the features of the anterior cruciate ligaments?

Answer 13

• Stops tibia moving forward on femur
• Stabilise knee in extension and prevents hyperextension and excessive internal rotation

Question 14

Describe the features of Posterior cruciate ligament

Answer 14

• Stops tibia moving backward on femur.
• Stronger the ACL
• Helps stabilise knee especially in flexion
• Also prevents tibia twisting outward (external rotation)

Question 15

What is the menisci?

Answer 15

•crescent shaped fibrocartilage disks between femoral and tibial condyles.

Question 16

Explain the morphology of the menisci? Outer and inner edge

Answer 16

• Outer edge of menisci thick and attach to joint capsule.
• Inside edge thin and essentially unattached.

Question 17

Which menisci is more commonly injured

Answer 17

•Medial meniscus more commonly injured than lateral.

Question 18

What is the Medial meniscus attached to?

Answer 18

medial collateral ligament and anterior cruciate ligament

Question 19

Name all the bursa in the knee

Answer 19

Suprapateller bursa

Superficial prepateller bursa

Deep infrapateller bursa

Superficial infrapateller bursa

Question 20

What are most bursas an extensions of? What are the bursas full of?

Answer 20

•extensions of the knee synovial cavity and are filled with synovial fluid.

Question 21

What is the functon of the bursa?

Answer 21

Act as cushions against friction and rubbing of the tendons, ligaments and bones around the knee joint

Question 22

Name the tendons above and below the patella?

Answer 22

Quadriceps tendon Above

Patellar ligament below

Question 23

What type of boen is the patella?

Answer 23

The largest sesamoid bone in the body

Question 24

What does the patella test, assess? What is the spinal root for the test?

Answer 24

Integrity of femoral nerve

Spinal roor L2-L4

Question 25

Name the bounderies of the popliteal fossa?

Answer 25

Biceps femoris

Semimembranosus and Semitendinosus

Medial and lateral head of gastrocnemius

Question 26

Describe the blood supply to the knee?

Answer 26

Popliteal artery- posterior

Superior and inferior lateral genicular artery

Superior and inferior medial genicular artery

Question 27

What passes through the popliteal fossa?

Answer 27

Tibial nerve

Popliteal artery and vein

Common peroneal nerve

sural nerve

Question 28

Label this Xray

Answer 28

Question 29

Which muscles are responsible for knee flextion? Which nerve innervates them?

Answer 29

•hamstrings (3 muscles at the back of the thigh)

Semimembranosus

Semitendinosus

Biceps femoris

•Innervated by sciatic nerve (tibial part)

Question 30

What effect does the politeus muscle have on the knee? Which nerve innovates this muscle?

Answer 30

• Weakly flexes knee
• Innervation tibial nerve
• Rotation
• Unlocks knee by rotating femur 5o laterally on fixed tibia
• When foot off the ground and knee flexed, rotates tibia medially

Question 31

Which muscles are responsible for knee extension?

Answer 31

• Quadriceps (4 muscles at the front of the thigh)
• Innervated by femoral nerve
• Quadriceps femoris = rectus femoris, vastus lateralis, vastus medialis, vastus intermedialis

Question 32

Which side of the knee carries the most body weight and why?

Answer 32

The medial side of the knee

Because the femure angles medially to carry body weight