The Knee

Question 1

What is the knee joint?

Answer 1

hinge joint with rotational component

designed for stability with weight bearing/mobility.

Question 2

What is the function of menisci?

Answer 2

improve joint congruity/stability
increase contact between femur and tibia for better load transmission across knee
disperses forces across entire knee
assists in lubrication and nutrition of joint.

Question 3

How many zones of the meniscus and what are they?

Answer 3

3 zones
red-red: highly vascular
red-white: less vascular
white-white: least vascular, least likely to heal

Question 4

What kind of joint is the knee?

Answer 4

synovial

Question 5

What ligaments stabilize the tibiofemoral joint?

Answer 5

anterior cruciate ligament

posterior cruciate ligament

Question 6

What 2 ligaments stabilize the medial and lateral sides of the knee?

Answer 6

medial collateral ligament (MCL)

lateral collateral ligament (LCL)

Question 7

What muscles make up the quadriceps femoris?

Answer 7

vastus medialis, vastus lateralis, vastus intermedius, and rectus femoris

Question 8

What muscles make up the hamstring group?

Answer 8

biceps femoris-long and short head, semitendinosus, semimembranosus.

Question 9

What is the functional anatomy of the knee?

Answer 9

required to do flexion, extension, rotation and arthrokinematic motions of rolling/gliding.

Question 10

What is the PCL’s purpose?

Answer 10

Limits anterior translation when tibia is fixed and posterior translation is non-weight bearing.

Question 11

What is the purpose of the ACL?

Answer 11

stop excessive internal rotation, stabilize the knee in full extension and prevents hyperextension.
limits posterior translation when tibia is fixed and anterior translation non-weight bearing.

Question 12

How does a medial collateral ligament sprain occur and how many grades are there?

Answer 12

severe blow from valgus force(lateral side).

3 grades.

Question 13

What are signs and symptoms for a grade 1 MCL sprain?

Answer 13

little fiber tearing/stretching, 
stable valgus test,
little to no joint effusion
some joint stiffness/point tenderness on lateral aspect
relatively normal ROM

Question 14

Management for grade 1 MCL sprain:

Answer 14

RICE 24 hrs
crutches if necessary
follow-up care will include cryokinetics w exercise
return to play when areas returned to normal
~ weeks to recover

Question 15

Signs and symptoms of grade 2 MCL sprain:

Answer 15

complete tear of deep capsular ligament + partial tear of superficial layer of MCL
no gross instability; laxity at 5-15degrees of flexion
slight swelling
moderate-severe joint tightness w decreased ROM
pain along medial aspect of knee.

Question 16

Management of grade 2 MCL sprain:

Answer 16

RICE 48-72 hrs; crutch use until acute phase resolved
possible brace/casting prior to initiation of ROM activities
modalities 2-3x daily for pain
gradual progression from isometric to isokinetic exercises; functional progression activities

Question 17

What are signs and symptoms of grade 3 MCL sprain?

Answer 17

complete tear of supporting ligaments
complete loss of medial stability
minimal-moderate swelling
immediate pain followed by ache
loss of motion due to effusion/ hamstring guarding
positive valgus stress test

Question 18

Management of MCL sprain grade 3:

Answer 18

RICE,
conservative non-operative versus surgical approach
- limited immobilization; progressive weight bearing & increased ROM over 4-6 weeks
rehab similar to grade 1/2 injuries.

Question 19

What is the cause of Lateral collateral ligament sprains?

Answer 19

varus force; generally w tibia internally rotated.

if severe enough, damage can occur to cruciate ligaments, ITB, meniscus and produce bony fragments.

Question 20

Signs and symptoms of LCL sprain:

Answer 20

pain & tenderness
swelling & effusion
joint laxity with varus testing
may cause irritation to peroneal nerve.

Question 21

Management of MCL injuries:

Answer 21

RICE
possible bracing
progression of exercises from isometric to isokinetic depending on severity.

Question 22

What is the etiology of the anterior cruciate ligament (ACL) sprain?

Answer 22

MOI- tibia internally rotated and valgus force at knee
linked to inability to decelerate valgus and rotational stresses- landing strategies
male versus female
impact to femoral notch, ACL size/laxity, Q-angle & faulty biomechanics
extrinsic factors: conditioning, skill acquisition, playing style, equipment
damage to other structures including meniscus, capsule and MCL

Question 23

Signs and symptoms of ACL sprain:

Answer 23

experience pop with severe pain and disability
positive anterior drawer and lachman’s or other ACL tests
rapid swelling at joint line

Question 24

Management for ACL sprain:

Answer 24

RICE; crutches
w/o surgery, joint degeneration may occur
age/activity may factor into surgical option
surgery may involve joint reconstruction w grafts
- bracing, 4-6 months rehab

Question 25

What is the etiology of Posterior Cruciate Ligament (PCL) sprain?

Answer 25

at risk during 90 degrees flexion
fall on bent knee
damaged due to rotational force

Question 26

What are signs and symptoms of PCL sprain?

Answer 26

feeling pop in back of knee
tenderness and relatively little swelling in popliteal fossa
laxity w posterior sag test

Question 27

Management for PCL sprains:

Answer 27

RICE

non-operative rehab of grade 1/2 injuries should focus on quad strength

Question 28

What are some causes for meniscal lesions?

Answer 28

similar to causes of ligament injury
combination of joint compression, valgus or varus loading, internal/external rotation.
tears are longitudinal, oblique or transverse

Question 29

What are signs and symptoms of meniscal lesions?

Answer 29

effusion developing over 48-72 hrs
joint line pain & loss of motion
intermittent locking/giving way
pain with squatting
chronic shows recurrent swelling or muscle atrophy

Question 30

What are management techniques for meniscal lesions?

Answer 30

non-locked knee with indication of tear recommend diagnostic testing
locking occurs- anesthesia to unlock joint w arthroscopic surgery
w surgery all efforts made to preserve meniscus
rehab allows partial weight bearing,
immobilization and gradual return to activity over 12 weeks.

Question 31

What are the special tests for knee assessment?

Answer 31

posterior sag sign
ballotable or patellar tap
brush or swipe test

Question 32

what occurs in a positive posterior sag sign test?

Answer 32

tibia drops back or sacks back on the femur

result is PCL sprain

Question 33

What occurs if the ballotable or patellar tap is positive?

Answer 33

downward movement of patella followed by a rebound (patella appears to float)
suggests moderate to severe joint effusion. (40-50mL)

Question 34

What occurs in a positive brush or swipe test?

Answer 34

fluid passes medially and bulges just below medial, distal border of patella.
suggests minimal joint effusion (4-8ml)

Question 35

What structures do you need to palpate during a knee assessment?

Answer 35

patella, tibial tuberosity, tibial plateau, medial collateral ligament, lateral collateral ligament, head of fibula.

Question 36

What is the purpose of the quadriceps femoris group?

Answer 36

extension of the knee.

Question 37

What quadricep muscle crosses two joints?

Answer 37

rectus femoris

Question 38

What is the “screw home mechanism”?

Answer 38

as knee extends, it externally rotates because medial femoral condyle is larger than lateral.
“locks” knee in terminal extension and allows rigid lever arm for gait.
popliteus “unlocks” screw home mechanism by slightly internally rotating tibia.