intrinsic structures

Question 1

What are the articular surfaces of the distal femur?

Answer 1

the medial condyle,
patellar articular surface,
lateral condyle

Question 2

Which condyle of the distal femur is longer?

Answer 2

medial condyle is longer—and not parallel

Question 3

What does all the surfaces of the distal femur condyle share?

Answer 3

one synovial cavity

Question 4

what type of rotation happens as a result of the lateral condyle being shorter than the medial?

Answer 4

At the end of extension, the lateral condyle runs out of travel room first, causing some lateral rotation (~5°) of the tibia on the femur, OR medial rotation of the femur on the fixed tibia.

Question 5

What are the menisci?

Answer 5

C-shaped pieces of fibrocartilage

Question 6

Which menisci is larger?

Answer 6

Medial is larger than lateral

Question 7

What is the function of the menisci?

Answer 7

Increase congruence (fit) of
elliptical femoral condyles onto
flat tibial condyles

Question 8

Which meniscus is more mobile?

Answer 8

lateral

Question 9

what is the lateral meniscus attached to?

Answer 9

Intercondylar eminence via horns
Posterior meniscofemoral ligament
Popliteus tendon
PCL

Question 10

What is the medial meniscus attached to?

Answer 10

Intercondylar eminence via horns
Meniscofemoral (to intercondylar fossa)
     and meniscopatellar fibers
Semimembranosus tendon (disputed)
Deep surface of joint capsule
MCL
this makes it less mobile because lack of connections to the joint capsule and LCL

Question 11

What are the cruciate ligaments?

Answer 11

anterior cruciate ligament

posterior cruciate ligament

Question 12

Where doe sthe cruciate ligaments pass and attach to?

Answer 12

ligaments pass each other in the space between the femoral condyles, and attach to the inner surfaces of the condyles.

Question 13

Where are the cruciate ligament ?

Answer 13

inside the joint capsule of the knee but outside the synovial membrane

Question 14

What is the function of the ACL?

Answer 14

resists anterior displacement of tibia on fixed femur, and posterior displacement of femur on fixed tibia.

Question 15

What is the function of the PCL?

Answer 15

resists posterior displacement of tibia on fixed femur, and anterior displacement of femur on fixed tibia.

Question 16

What does ACL tears often result from?

Answer 16

frontal impact on thigh when foot is fixed, especially when medial rotation of the thigh or lateral rotation of the leg are involved.

Question 17

What is the positive anterior drawer sign?

Answer 17

broken ACL does not resist displacement of tibia on fixed femur; the leg slides forward like an opening drawer.

Question 18

What is a unhappy triad?

Answer 18

torn ACL, torn MCL, and torn medial mensicus.

Question 19

What is the cause of an unhappy triad?

Answer 19

Forced medial rotation of lower limb with fixed foot

Question 20

Why is emphasis placed on regaining strength in the quads and hamstrings in a recovery of a cruciate ligament tear?

Answer 20

quadriceps and hamstrings are vital dynamic stabilizers of the kneetheir posterior pull on the tibia, the hamstrings can help prevent anterior translation of the tibia relative to the femur and relieve stress on a maturing ACL graft.

Question 21

where does the anterolateral ligament attach?

Answer 21

proximally at the lateral epicondyle of the femur and distally to the proximal tibia just lateral to Gerdy’s tubercle (the site of insertion of the iliotibial tract).

Question 22

What is a seconds fracture?

Answer 22

ALL is frequently avulsed from the proximal tibia during forced medial rotation of the femur relative to the tibia.

Question 23

What is the normal function of the ALL?

Answer 23

to help stabilize the knee during internal rotation