The knee joint

Question 1

What is the knee joint?

Answer 1

Hinge type synovial joint. Consists of articukations between patella and femur, and tibia and femur. Joints are lined with hyaline cartilage

Question 2

Describe the tibiofemoral joint?

Answer 2

Medial and lateral condyles of the femur articulate with the tibial condyles. It is the weight bearing component of the knee.

Question 3

Describe the patellofemoral joint?

Answer 3

Anterior aspect of the distal femur articulates with the patella. It allows the tendon of the quadriceps femoris to be inserted directly over the knee increasing efficiency of the muscle

Question 4

Why is the patella such a key structure?

Answer 4

The patella both forms and resides within the quadriceps femoris tendon, it provides a fulcrum to increase the power of the knee extensor and serves as a stabilising structure that reduces frictional forces placed on the femoral condyles

Question 5

What is the arterial supply of the knee?

What is the nervous supply of the knee?

Answer 5

Genicular anastomoses, supplied by genicular branches of the femoral and popliteal arteries

Question 6

Describe the menisci of the knee

Answer 6

Two fibrocartilagenous structures, medial and lateral menisci. Act to deepen articular surface of tibia to increase stability and act as shock absorbers

Question 7

Describe the anatomy of the lateral and medial menisci of the knee

Answer 7

C shaped and attach at both ends to the intercondyler area of the tibia.
Medial meniscus is fixed to the tibial collateral ligament and the joint capsule
Lateral meniscus is smaller and does not have any extra attachments

Question 8

What are the bursae of the knee?

Answer 8

Suprapatella bursa- located between quadriceps femoris and femur

Prepatella bursa- apex of patella and skin

Infrapatella bursa- deep and superficial.Depp- tibia and patella ligament Superfificial- Patella ligmanet and skin

Located posteriorly in the knee between semimembranosus muscle and medial head of gastrocnemius

Question 9

What is the patellar ligament?

Answer 9

Continuation of quadriceps femoris, attaches to tibial tuberosity

Question 10

What are the collateral ligaments?

Answer 10

Two strap like ligaments on either side of the knee

Medial collateral ligament- wide flat ligament found on the medial side of the joint. Proximally it attaches to the medial epicondyle of the femur. Distally attaches to medial condyle of tibia

Lateral collateral ligmanet- Thinenr and roudned than th etibial collateral, this attaches proximally to the lateral epicondyle of the femur, distally it attahces to a depression on the lateral surface of the fibular head

Question 11

What are the cruciate ligaments?

Answer 11

Two ligaments that connect the femur and the tibia. In doing so they cross each other, hence the term cruciate (latin for corss)

ACL- attaches to anterior intercondylar region of the tibia where it blends with the medial meniscus. It ascends posteriorly to attach femur to intercondylar fossa

PCL- attaches at the posterior intercondylar region of the tibia. Ascends and attaches anteriorly to the anteromedial femoral condyle

Question 12

What are the four movements on the knee joint?

Answer 12

Extension
Lateral rotation
Medial rotation
Flexion

Question 13

What muscles are responsible for extension of the knee

Answer 13

Produced by quadriceps femoris which inserts into tibia tuberosity

Question 14

What muscles are responsible for flexion of the knee?

Answer 14

Produced by hamstirngs, gracilis, sartorius and popliteus

Question 15

What muscles are responsible for lateral rotation of the knee

Answer 15

Biceps femoris

Question 16

What muscles are responsible for medial rotation of the knee?

Answer 16

Semimembranous, semitendinous, gracilis, sartorius and popliteus

Question 17

What is the most common injury of the knee

Answer 17

Damage to the collateral ligaments. Caused by force being applied to the side of the knee while the foot is planted

If medial collateral ligament is damaged then it is more than likely that the medial meniscus is torn

Question 18

Describe an ACL injury

Answer 18

Hyperextension of the knee joint or application of a large force to the back of the knee with the joint partly flexed.

Question 19

Describe a PCL injury

Answer 19

Typically a dashboard injury where the knees hit the dashboard. Can also be torn by hyperextension of the knee or by damage to the upper part of the tibial tuberosity