MSK- KNEE JOINT

Question 1

What are the two articulations (names of joints) of the knee joint

Answer 1

• Patellofemoral joint
  -Tibiofemoral joint

Question 2

What type of joint is the tibiofemoral joint?

Answer 2

Synovial joint, modified bicondylar hinge joint

Question 3

What are the main movements of the tibiofemoral joint?

Answer 3

• Flexion and Extension
• also allows the femur to rotate on the tibia (Medial and Lateral rotation). This rotation also contributes to the “locking” mechanism of the knee when fully extended, particularly when standing

Question 4

What is the main function of the Femur?

Answer 4

Transmits body weight from the hip bone to the tibia in weightbearing

Question 5

What are the 5 extra capsular ligaments of the knee?

Answer 5

• Patella ligament
  -Medial (tibial) collateral ligament
  -Lateral (fibular) collateral ligament
• Oblique Popliteal ligament
  -Arcuate Popliteal ligament

Question 6

What are the two intra-capsular ligaments of the knee?

Answer 6

• Anterior Cruciate ligament
• Posterior Cruciate ligament

Question 7

What are the two C-shaped fibrocartilages called in the knee?

Answer 7

-Medial menisci
-Lateral menisci

Question 8

What is the definition of a bursa?, and what is the function?

Answer 8

Synovial fluid filled sacs, found between moving structures in a joint, aim is to reduce friction during movement

Question 9

When is the knee joint the most stable and why?

Answer 9

-Most stability in extension
- as all ligaments are taut in extension
- relies on muscles of the thigh to increase stability when not fully extended

Question 10

What are the bones and articulating surfaces involved in the Patellofemoral joint, and what type of joint is it?

Answer 10

• bones: patella, femur
• articulating surfaces: posterior surface of patella and trochlear groove of femur
• synovial, plane joint

Question 11

What ligaments are involved in the Patellofemoral joint?

Answer 11

• Medial Patellofemoral ligament
• Lateral Patellofemoral ligament
• Patella ligament
• Retinaculum

Question 12

What muscles are involved in the Patellofemoral joint, and what is their role?

Answer 12

• Vastus Medialis: medial restraint to lateral translation of patella
• vastus Lateralis: lateral restraint to medial translation of patella
• Dynamic stability of the patella within the trochlear groove

Question 13

What is the movement and function of the Patellofemoral joint?

Answer 13

• patella moves in a sliding motion within the trochlear groove
• during knee flexion the patella moves caudally, maximum contact is at 45 degrees of flexion
• increase in extensor strength by increasing the movement arm of the extensor mechanism on the tibia
• transmits tensile forces generated by the quadriceps to the patellar tendon

Question 14

Superior Tibiofibular Joint- what type of joint is it?, what are the articulating surfaces?, what is it’s role? What are the ligaments/supporting structures involved? What structure links the tibia and fibula along their lengths?

Answer 14

-Plane synovial joint
-Between fibular head and lateral condyle of tibia
- minimal movement, role in stability and weight bearing
- the joint capsule receives additional support from: anterior and posterior superior tibiofibular ligaments, lateral collateral ligament of the knee joint, biceps Femoris
- tibia and fibula are linked along their lengths by an interosseous membrane

Question 15

What muscles are there in the Anterior Compartment of the thigh?

Answer 15

• Psoas Major
• Iliacus
• Rectus Femoris
• Vastus Medialis
• Vastus Lateralis
• Sartorius
• Pectineus

Question 16

What muscles are there in the Posterior Compartment of the thigh?

Answer 16

• Semitendinosus
• Semimembranosus
• Biceps Femoris (long head)
• Biceps Femoris (short head)

Question 17

What are the muscles of the knee (knee extensors, knee flexors, medial/lateral rotators)

Answer 17

• Extensors: anterior compartment (quadriceps)- Rectus Femoris, Vastus Lateralis, Vastus Intermedius, Vastus Medialis
• Flexors: posterior compartment (hamstrings)- Biceps Femoris, Semimembranosus, Semitendinosus
• Lateral Rotators: Biceps Femoris
  -Medial Rotators: semimembranosus, semitendinosus, gracilis, sartorius, popliteus

Question 18

What are the two components of the knee “locking” mechanism?
What happens during the unlocking of the knee?

Answer 18

• as the knee extends, the curved parts of the femoral condyles roll and slide posteriorly so the inferior broad and flat areas of the femoral condyles sit on the tibial condyles = joint surfaces become larger and more stable in extension
• medial rotation of the femur on the tibia occurs in last 30 degrees of extension- tightens all the associated ligaments
• unlocking the knee (flexion)- the popliteus muscle unlocks the knee by initiating lateral rotation of the femur on the tibia