11/30 Knee + Leg

Question 1

What is the superior border of the popliteal fossa?

Answer 1

Hamstrings
Laterally biceps femoris muscle
Medially semimembranosus muscle

Question 2

What is the inferior border of the popliteal fossa?

Answer 2

Gastrocnemius muscle (lateral & medial heads)

Question 3

What is the posterior (roof) border of the popliteal fossa?

Answer 3

Skin, popliteal fascia

Question 4

What is the anterior (floor) border of the popliteal fossa?

Answer 4

Femur, investing popliteus fascia/muscle

Question 5

What are the nerves of the popliteal fossa?

Answer 5

Sciatic nerve (L4-S3)
Branches into: Tibial nerve (L4-S3), common fibular nerve (L4-S2)

Question 6

Where does the tibial nerve go? What is the cutaneous branching?

Answer 6

Continues within the posterior leg
Medial sural cutaneous nerve (contributes to sural nerve)

Question 7

Where does the common fibular nerve go? What is the cutaneous branching?

Answer 7

Divides into superficial and deep fibular nerve
Continues within the lateral and anterior leg
Lateral sural cutaneous nerve (contributes to sural nerve)

Question 8

What is the largest and most superficial joint?

Answer 8

The knee

Question 9

What kind of joint is the knee?

Answer 9

Primarily a hinge type of synovial joint (flexion/extension), also does gliding and rotation about a vertical axis

Question 10

What are the articulations of the knee?

Answer 10

2 femorotibial articulations, lateral and medial
1 femoropatellar articulation

Question 11

What bone is not involved in the knee joint?

Answer 11

The fibula

Question 12

The strength of the knee joint is dependent on?

Answer 12

Strength of the associated muscles and ligaments

Question 13

What provides the most muscular stabilization of the knee? What is the most stable position of the knee?

Answer 13

Quadriceps femoris
Extended knee (taut ligaments)

Question 14

What is the Q-Angle?

Answer 14

A line representing the resultant line of force of the quadriceps, made by connecting a point near the ASIS to the mid-point of the patella
A line of gravity, “weight-bearing line”.

Question 15

What mechanism locks the knee in full extension?

Answer 15

“Screw Home” mechanism

Question 16

Where does the “screw home” mechanism occur? What allows this to happen?

Answer 16

Occurs between 20 degrees of knee flexion and full extension
A combination of lateral rotation of the tibia and passive medial rotation of the femur

Question 17

What is the result of the “screw home” mechanism

Answer 17

tightening of both cruciate ligaments, which locks the knee in extension

Question 18

How does the “screw home” mechanism unlock?

Answer 18

Popliteus muscle initiates “unlocking” followed by lateral rotation of femur to enable knee flexion

Question 19

What is the knee joint capsule made of?

Answer 19

External fibrous layer, internal synovial membrane

Question 20

What is the external fibrous layer of the knee joint capsule?

Answer 20

Incomplete external portion of the capsule

Question 21

What is the internal synovial membrane of the knee joint capsule?

Answer 21

Completely lines the articular cavity
Lines the internal surface of the fibrous layer laterally and medially but separates centrally
Posteriorly reflects into the intercondylar area almost separating the R&L femorotibial articular cavities

Question 22

How is the joint capsule of the knee strengthened?

Answer 22

By 5 extracapsular ligaments

Question 23

What are the 5 extracapsular ligaments which strengthen the knee joint (anterior/posterior)?

Answer 23

Anterior: Patellar tendon, fibular/lateral collateral ligament (F/LCL), tibial/medial collateral ligament (T/MCL)
Posterior: oblique popliteal ligament, arcuate popliteal ligament

Question 24

What is the patellar tendon and where does it attach?

Answer 24

Distal extension of the quadriceps tendon
Attaches to tibial tuberosity

Question 25

What is the Fibular/Lateral Collateral Ligament (F/LCL) and where does it attach?

Answer 25

Strong “cord-like” band of dense C.T. Lateral epicondyle of femur to head of fibula

Question 26

Where does the popliteus tendon pass?

Answer 26

Between Fibular/lateral collateral ligament and lateral meniscus

Question 27

What is the Tibial/Medial Collateral Ligament (T/MCL)? Where does it attach?

Answer 27

Weaker than FCL Medial epicondyle of femur to: • Medial meniscus • Medial surface of tibia

Question 28

What is the Tibial/Medial Collateral Ligament (T/MCL) deep to?

Answer 28

Pes anserinus

Question 29

What is the oblique popliteal Ligament?

Answer 29

Expansion of the semimembranosus tendon

Question 30

Where does the arcuate popliteal ligament arise from?

Answer 30

Arises from the fibular head

Question 31

Intra-articular ligaments originate and insert within the knee joint and consists of

Answer 31

Cruciate ligaments and menisci

Question 32

Where do cruciate ligaments run?

Answer 32

cross obliquely within the joint capsule but outside the synovial cavity

Question 33

What are the types of cruciate ligaments?

Answer 33

Anterior cruciate ligament (ACL) Posterior cruciate ligament (PCL)

Question 34

What does the anterior cruciate ligament (ACL) do?

Answer 34

Prevents anterior displacement of tibia on femur Limits tibia movement anteriorly (knee flexed)

Question 35

What does the posterior cruciate ligament (PCL) do?

Answer 35

Prevents posterior displacement of tibia on femur Limits tibia movement posteriorly (knee flexed)

Question 36

What are menisci?

Answer 36

crescent plates of fibrocartilage on the articular surface of the tibia

Question 37

What do menisci do?

Answer 37

Deepen articular surface and absorbs mechanical load

Question 38

What attaches to the menisci?

Answer 38

Coronary ligaments Transverse ligament of the knee MCL

Question 39

Where are the coronary ligaments?

Answer 39

Extend from the joint capsule to the margins of the menisci/tibia

Question 40

What does the transverse ligament of the knee do?

Answer 40

Joins the anterior margins of the menisci

Question 41

What are the menisci of the knee?

Answer 41

Medial meniscus Lateral meniscus

Question 42

What is the medial meniscus?

Answer 42

C shaped Attachment to TCL

Question 43

What is the lateral meniscus?

Answer 43

Nearly circular More mobile

Question 44

What are the movements of the ankle?

Answer 44

Dorsiflexion (extension) Plantarflexion (flexion)

Question 45

What allows dorsiflexion of the ankle?

Answer 45

Muscles/tendons from the anterior compartment of leg

Question 46

What allows plantarflexion of the ankle?

Answer 46

Muscles/tendons from the posterior and lateral compartments of leg

Question 47

What movements does the foot allow?

Answer 47

Flexion/extension of toes Stabilization of foot arches

Question 48

What is the popliteal artery a continuation of? When does this change take place?

Answer 48

From femoral artery After passing through adductor hiatus Runs to inferior border of popliteus

Question 49

What makes up the superior part of the knee anastomoses before the edge of patella? Where do they come from?

Answer 49

Descending branch of lateral femoral circumflex artery - from deep femoral (lateral) Descending genicular artery - from femoral (medial)

Question 50

What makes up the parts of the knee anastomoses surrounding the patella? Where do they come from?

Answer 50

Superior and inferior lateral genicular artery Superior and inferior medial genicular artery Middle genicular artery (posterior to anterior through knee joint) All branch from popliteal artery (all but middle start posteriorly and come anteriorly around the sides of femur/tibia/fibula)

Question 51

When the popliteal artery divides, what does it become?

Answer 51

Anterior and posterior tibial arteries

Question 52

What does the anterior tibial artery give rise to?

Answer 52

Anterior tibial recurrent artery (part of genicular anastomosis)

Question 53

What does the posterior tibial artery give rise to?

Answer 53

Fibular artery

Question 54

What does the bowleg stance do to the coxa and genu angles? What about Q-angle and condylar separation?

Answer 54

Coxa valgus Genu varus Q-angle is decreased/smaller Condylar separation laterally

Question 55

What does the knock-knee stance do to the coxa and genu angles? What about Q-angle and condylar separation?

Answer 55

Coxa varus Genu valgus Q-angle is increased/bigger Condylar separation medially

Question 56

The anterior compartment of the thigh promotes this knee joint movement Which nerve innervates these muscles?

Answer 56

Knee extension Femoral nerve

Question 57

The posterior compartment of the thigh promotes this knee joint movement Which nerve innervates these muscles?

Answer 57

Knee flexion Tibial nerve (short head of biceps femoris is common fibular)

Question 58

Which muscles provide flexion of the knee? What is their innervation?

Answer 58

Gracilis - obturator nerve Hamstrings (semitendinosus, semimembranosus, biceps femoris) - tibial nerve (short head of biceps femoris is common fibular) Sartorius - femoral nerve

Question 59

What makes up the pes anerinus?

Answer 59

semitendinosus, gracilis, and sartorius muscles

Question 60

What is torn in a compound knee injury? What can also happen?

Answer 60

“Terrible triad” Torn: anterior cruciate ligament, tibial collateral ligament, medial meniscus Can also have a crushing injury to lateral meniscus

Question 61

What muscles make up the anterior compartment of the leg? What movement do they perform?

Answer 61

Tibialis anterior, extensor hallicus longus, extensor digitorum longus, fibularis tertius Dorsiflexion

Question 62

What is the neurovascular supply to the anterior compartment of the leg?

Answer 62

Deep fibular nerve Anterior tibial artery/vein

Question 63

What muscles make up the lateral compartment of the leg? What movement do they perform?

Answer 63

Fibularis brevis, fibularis longus Plantar flexion and eversion

Question 64

What is the neurovascular supply of the lateral compartment of the leg?

Answer 64

Superficial fibular nerve

Question 65

What muscles make up the posterior compartment of the leg? What movement do they perform?

Answer 65

Flexor digitorum longus, tibialis posterior, plantaris, soleus, gastrocnemius, flexor hallucis longus Plantarflexion

Question 66

What is the neurovascular supply of the posterior compartment of the leg?

Answer 66

Tibial nerve Posterior tibial artery/nerve, fibular artery/nerve