Chapter Five: The Knee Joint

Question 1

function of the knee

Answer 1

• most complex joint in the body
• bears most of the weight of the body
• flexible enough for locomotory function

Question 2

classification

Answer 2

modified hinge joint

Question 3

movements

Answer 3

• flexion and extension
• medial and lateral rotation
• performs act of locking and unlocking the knee

Question 4

bony parts and menisci

Answer 4

• two femoral condyles rotate on their two tibial condyles
• medial condyles are larger than lateral condyles
• bony surfaces do not match well
• pair of menisci cartilages fixed to the tibial condyles borders to accept the condyles of the femur

Question 5

lateral meniscus

Answer 5

• more circular and attached at the two ends
• round and only attached centrally
• moves in an anterior and posterior fashion during extension

Question 6

medial meniscus

Answer 6

• more ab ab ellipse shape and is attached to the tibia throughout its length
• it does not move so it is more likely to be damaged

Question 7

bursa

Answer 7

• joint space includes the patellar femoral joint
• extends upwards above the patella onto the femur as the supra patellar bursa
• important during deep flexion
• fibrous capsule forms loosely around the joint

Question 8

ligaments of the knee

Answer 8

• collateral ligaments are known as the medial and lateral collateral ligaments

Question 9

medial collateral ligament

Answer 9

• is a bipartite; its deep part is fan shaped and derived from the fibrous capsule
• superficial portion is a cord running from the medial epicondyle to insert on the shaft of the tibia

Question 10

lateral collateral ligament

Answer 10

• thick cord passing from the lateral epicondyle to the head of the fibula

Question 11

the cruciate ligaments

Answer 11

• they cross each other
• they’re crucial to the proper functioning of the joint
• located in the space between the two halves of the joint (not in the joint space)

Question 12

anterior cruciate (ACL)

Answer 12

• runs up from the medial tibial condyle and back yo the inside of the lateral femoral condyle
• prevents backward dislocation of the femur and hyperextension

Question 13

posterior cruciate (PCL)

Answer 13

• runs forward, upward and medially from the back of the intercondylor emminence to the inside of the medial femoral condyle
• prevents forward dislocation of the femur

Question 14

function of ALC & PLC

Answer 14

• these four ligaments (the ALC, PLC and collaterals act together during the end of full extension of the knee and in the locking mechanism
• towards full extension a little medial rotation of the femur occurs and all four ligaments tighten up, securing the joint

Question 15

blood and nerve supply to the knee

Answer 15

• the arterial supply to the knee derives from the popliteal artery

Question 16

popliteal artery

Answer 16

• this artery enters the popliteal fossa through the adductor hiatus and runs straight down behind the knee joint
• gives off three pairs of geniculate arteries called the superior, middle and inferior genicular arteries

Question 17

anterior and posterior tibial arteries

Answer 17

• at the bottom of the popliteal fossa, the popliteal artery bifurcates forming the anterior and posterior tibial arteries