The Knee Joint

Question 1

What type of joint is the knee joint?

Answer 1

The knee joint is a synovial hinge joint, capable of flexion, extension and a small amount of active and passive axial rotation

Question 2

Answer 2

1. Patella 2. Fibula 3. Tibia 4. Femur

a. Femur: Medial condyle b. Femur: Lateral condyle c. Tibia: Lateral condyle d. Tibia: medial condyle e. Tibia: Tibia; tuberosity

Question 3

Articular surfaces choose from:

Answer 3

• Medial Femoral Condyle
• Lateral Tibial Condyle
• Tibial Tuberosity
• Medial Tibial Condyle
• Lateral Femoral Condyle

Question 4

What does the stability of the knee joint depend on?

Answer 4

Depends on the strength and action of surrounding muscles and their tendons and ligaments connecting the femur and tibia.

Question 5

Which is the most important muscle which helps to stabilize the knee joint?

Answer 5

Hamstring muscle

Question 6

What are the ligaments of the knee joint?

Answer 6

Thickening of the joint capsule

Question 7

Answer 7

1. Lateral collateral ligament
2. Medial collateral ligament
3. Anterior cruciate ligament
4. Posterior cruciate ligament

Question 8

The fibular, or lateral collateral ligament (LCL) extends from?

Answer 8

The lateral epicondyle of the femur to the lateral surface of the head of the fibula.

Question 9

Where does the tendon of the popliteus muscle pass?

Answer 9

Deep to the LCL, separating it from the lateral meniscus.

Question 10

The tibial, or medial collateral ligament (MCL) extends from what?

Answer 10

The medial epicondyle of the femur to the medial surface of the tibia, with an attachment to the medial epicondyle of the tibia.

Question 11

What does the medial collateral ligament attached onto at its midpoint?

Answer 11

The medial meniscus of the knee

Question 12

Why is the attachment of the MCL to the medial meniscus clinically important?

Answer 12

Critical in maintaining stability of the knee joint

Question 13

Where do the cruicate ligaments cross?

Answer 13

The cruciate ligaments cross each obliquely in the knee to form an ‘X’ shape

Question 14

The anterior cruciate ligament (ACL) prevents what?

Answer 14

The femur from sliding posterior (anterior or posterior?) on the tibia.

Question 15

The posterior cruicate ligament prevents what?

Answer 15

The femur from sliding anterior (anterior or posterior?) on the tibia.

Question 16

Why do anterior cruicate ligament injuries mean a long time out of playing sport?

Answer 16

The ACL is a vital component in providing stability to the knee joint, preventing the femur from sliding on the tibia.

After repair due to the poor blood supply to the ACL, it can take a long time to heal

Question 17

Which crucicate ligament damage is less common?

Answer 17

PCL tear/rupture is less common due to the force required by a direct blow on the tibia to cause injury, compared to the twisting decelerating motions required to disrupt the ACL.

Question 18

What is this?

Answer 18

Popliteus muscle

Question 19

What is the popliteus muscle important in?

Answer 19

Helping release the fully extneded or locked knee

Question 20

What happens when flexing from a fully extended position with the popliteus muscle

Answer 20

The muscle rotates the femur laterally on the tibia (or vice-versa), allowing for the unimpeded movement of the joint

Question 21

What are menisci?

Answer 21

Crescent shaped plates of fibrocartilage directly on the articular surface of tibia.

Question 22

What is this?

Answer 22

Menisci

Question 23

Identify the structures labelled 1 to 4 on the above diagram

Answer 23

1. Medial meniscus
2. Lateral meniscus
3. Anterior cruciate ligament
4. Posterior cruciate ligament

Question 24

What are the main functions of the menisci?

Answer 24

Stability to the femorotibial articulation, distribute axial load, absorb shock and provide lubrication for the knee joint

Question 25

Which meniscus firmly adheres to the deep surface of the tibial or medial collateral ligament?

Answer 25

The medial meniscus

Question 26

What are menisceal tears?

Answer 26

One of the most common injuries around the knee joint are due disruptions to the cartilage or meniscal tears.

Because of the shape of the menisci, any lateral impact to the knee joint risks both damaging the medial meniscus and disrupting both the ACL and medial collateral ligaments.

If the cartilage becomes loose within joint space, there is a risk that the knee can become ‘locked in fixed flexion or extension

Question 27

What is the patella?

Answer 27

Largest sesamoid bone in the body, sitting at the anterior of the knee joint and acting as an anchor point for the quadratus femorus tendon superiorly and patellar ligament inferiorly.

Question 28

Which movement of the knee causes the patella to move?

Answer 28

Extension

Question 29

Answer 29

Question 30

Which bursa communicates with the articular cavity of the knee joint?

Answer 30

Suprapatellar

Question 31

What is the clinical significance of the burs communicates with the articular cavity of the knee joint?

Answer 31

Allows for movement of the quadriceps tendon over the distal end of the femur

Question 32

What is housemaids knee?

Answer 32

Inflammation of the bursa in front of the kneecap

Question 33

What are the muscles involved in movements of the knee joint?

Answer 33

Knee flexion: 3 hamstring muscles- Semimembranousus, semitendinosus, biceps femoris, Sartorius and Gracilis

Knee extension: Quadriceps- 4 heads. Vastus intermedius, vastus lateralis, vastus medialis, rectus femoris