Anatomy II Lecture 11: Knee and Popliteal Fossa

Question 1

What are the femoral condyles separated anteriorly by?

Answer 1

Patellar surface

An asymmetric, shallow, saddle-shaped groove

Question 2

What are the femoral condyles separated by posteriorly by?

Answer 2

Intercondylar fossa

Question 3

What are the articulating surfaces of the tibiofemoral joint?

Answer 3

Femoral condyles and the tibial plateaus

Question 4

T/F the medial tibial plateaus is larger than that of the lateral

Answer 4

True

Question 5

What are the medial and lateral tibial plateaus separated by?

Answer 5

Intercondylar tubercles

Question 6

The menisci is a(n)____

Answer 6

The menisci is a wedged-shaped fibrocartilage disc

Question 7

Coronary ligaments and the anterior transverse ligaments are attached to the

Answer 7

Menisci

Question 8

T/F the menisci are highly vascularized

Answer 8

False

Question 9

T/F there is no loss of knee function when the menisci are removed

Answer 9

True

Question 10

Which of the menisci is larger and more likely to get injured?

Answer 10

The Medial Meniscus

Opposed to the lateral meniscus

Question 11

What enhances the stability of the knee by distributing weight, deepening the articular surfaces, and reduces friction between articular surfaces?

Answer 11

The menisci

Question 12

Describe the movement of the medial meniscus during extension and flexion

Answer 12

Extension: Moves posteriorly (due to tension in semimembranous muscle)
Flexion: Drawn forward (due to tension in anterior capsular fibers)

Question 13

What is:
Large and Lax
Deficient on lateral condyle: For passage of the popliteal tendon
Anterior wall replaced by quadriceps tendon
Excludes cruciate ligaments
Commonly communicates with synovial bursae

Answer 13

Joint Capsule

Question 14

Upward expansion of synovial cavity between femur and quadriceps muscles and tendon
Proximally receives insertion of articularis genus muscle

Answer 14

Suprapatellar Bursa

Question 15

Lies between superficial surface of patella and skin

Answer 15

Prepatellar Bursa

Question 16

Lies between patellar ligament and tibia

May become inflamed as a result of excessive kneeling

Answer 16

Deep Infrapatellar Bursa ***

Question 17

Located between tendon popliteus muscle and later condyle of tibia

Answer 17

Subpopliteal Bursae

Question 18

Under medial head of gastrocnemius

Answer 18

Gastrocnemius Bursae

Question 19

What is a Bursa (Bursae)?

Answer 19

a fluid-filled sac or saclike cavity, especially one countering friction at a joint.

Question 20

Between pes anserinus and tibial collateral ligament

Answer 20

Anserine Bursa

Note: Pes anserine = combined tendons of semitendinosus, gracilis, and sartorius

Question 21

The medial collateral ligament is a connection between___

Answer 21

The medial femoral condyle and the proximal tubule

Note that it is continuous with the adductor Magnus tendon and is associated with the meniscus

Question 22

What splits the tendon of biceps femoris muscle?

Hint: It also is separated from lateral meniscus by popliteal tendon

Answer 22

Lateral (fibular) collateral ligament

Question 23

What ligament prevents backward sliding of the femur on the tibia and prevents hyperextension of the knee?

Answer 23

Anterior cruciate

Question 24

What ligament is slack during flexion and taut during extension?

Answer 24

Anterior cruciate

Question 25

What ligament is taut during flexion and is slack during extension?

Answer 25

Posterior cruciate

Question 26

What ligament prevents forward siding of the fumer on the tibia and prevents hyperextension of the knee?

Answer 26

Posterior cruciate

Question 27

During the first part, in flexing the knee, what is happening?

Answer 27

Posterior rolling and spinning | Rolling femur posteriorly and spinning condyle on the plateau

Question 28

When does anterior sliding of the femoral condyles on tibial plateaus occur?

Answer 28

Flexion of the knee

Question 29

During the first part, in extension the knee, what is happening?

Answer 29

Femoral condyles roll anteriorly and slide posteriorly Note: This is followed by rolling and spinning of condyles

Question 30

When the knee is flexed at a 90-degrees angle, how many degrees can the tibia rotate?

Answer 30

30 degrees of medial rotation | 40 degrees of lateral rotation

Question 31

T/F When the knee is flexed GREATER than 90-degrees, medial and lateral rotation's range of motion increases

Answer 31

False; it decreases

Question 32

Where is the patella embedded?

Answer 32

The joint Capsule

Question 33

Between what two structures can the patella be found and attached to?

Answer 33

Attached to the quadriceps via the quadriceps tendon and to the tibial tuberosity via the ligamentum patellae

Question 34

The central ridge of the patella slides along the central groove of the femur during

Answer 34

knee flexion/extension of the patellofemoral joint

Question 35

The tibia moves posteriorly and the ligamentum patellae pulls the patella distally and posteriorly during

Answer 35

Flexion of the patellofemoral joint Note that the ligamentum patellae pulls the patella distally and posteriorly causes the patella to remain firmly in apposition to the femur

Question 36

The patella is pulled proximally to the quadriceps, the vastus lateralis tends to pull the patella laterally, and the vastus medialis oblique counteracts vastus lateralis during

Answer 36

extension of the patellofemoral joint

Question 37

Q-angle of the patellofemoral joint

Answer 37

is formed by - vector of quadriceps (From ASIS to middle of patella) And vector of pull of ligamentum patellae (from tibial tubercle to middle of patella 15 degrees

Question 38

What happens to the femur during the last few degrees of extension?

Answer 38

Femur rotates medially on tibia | Note that the tibia would also rotate on the femur laterally

Question 39

What is the locked or screw-home mechanism?

Answer 39

Tibial tubercles are lodged in intercondylar notch + Menisci are tightly interposed between tibial and femoral condyles This happens during the final few degrees of extension (Locking at full extension)

Question 40

What laterally rotates femur for unlocking at the beginning of knee flexion?

Answer 40

The popliteus | He especially noted this

Question 41

What is a medial deviation of the tibia reuslting in a greater than 170 degree angle and results in "bow legs"

Answer 41

Genu varum

Question 42

What is a lateral deviation of the tibia resulting in a lesser than 170 degree angle and results in "knock knees"

Answer 42

Gen valgum

Question 43

What is the normal angle at the knee where femoral and tibial axes meet?

Answer 43

170-175 degrees

Question 44

What is the mechanical axis of the knee?

Answer 44

Head of femur to head of talus

Question 45

Where does the anatomic axis of the knee extend?

Answer 45

Extends along the femoral shaft

Question 46

T/F the popliteal fossa is the anterior aspect of the knee?

Answer 46

False it is the posterior

Question 47

What is the bony landmark of the popliteal fossa?

Answer 47

The popliteal surface of the femur (floor)

Question 48

What are the boundaries of the popliteal fossa?

Answer 48

Superior: Semimembranous and semitendinosus Inferior: Medial and lateral heads of gastrocnemius

Question 49

What is contained in the popliteal fossa?

Answer 49

``` Fat Several popliteal lymph nodes Popliteal bursa Superficial to deep: Tibial Nerve, Popliteal Vein, Popliteal Artery Common Peroneal (fibular) nerve Small saphenous vein ```

Question 50

The popliteal arty is a continuation of the

Answer 50

femoral artery

Question 51

The lateral and medial superior geniculars, The lateral and medial inferior geniculars, and the Middle genicular are branches off of

Answer 51

The popliteal artery | Note: they create the genicular anastomoses

Question 52

What divides into anterior and posterior tibial arteries?

Answer 52

Popliteal artery

Question 53

What is the popliteal vein formed by?

Answer 53

Venae comitantes | Note: it receives from the small saphenous vein and becomes the femoral vein at the adductor hiatus

Question 54

The tibial nerve is a part of the

Answer 54

Sciatic nerve

Question 55

The common peroneal fibular nerve is part of the

Answer 55

Sciatic Nerve

Question 56

Sural nerve arises from

Answer 56

the tibial nerve

Question 57

What forms the genicular anastomosis

Answer 57

Genicular branches of the popliteal artery Branches of anterior tibial: circumflex fibular and anterior tibial recurrent Branches of posterior tibial: posterior tibial recurrent Note: it is a branch from the femoral artery via the descending genicular artery