lecture 7- knee

Question 1

bones of the knee

Answer 1

femur
tibia
patella

Question 2

2 articulations of the knee

Answer 2

Tibiofemoral
- femur and tibia

Patellofemoral
- patella and femur

Question 3

what 5 things help with stability of the knee?

Answer 3

capsule, ligaments, menisci, muscles, tendons

Question 4

Capsule of the knee

Answer 4

the joint capsule on the back is tight

the joint capsule on the back is extensive and redundant (allows joint flexion)

resists hyperextension

provides rotational stability

Question 5

Extracapsular ligaments of the knee

Answer 5

MCL (medial collateral)
LCL

Question 6

what movement do the collateral ligaments prevent?

Answer 6

side to side movements of the knee

Question 7

Intracapsular ligaments of the knee

Answer 7

ACL
- prevents anterior displacement of tibia on fixed femur, hyperextension
PCL
-prevents posterior displacement of tibia on fixed femur

Question 8

what does the posterior cruciate ligament prevent?

Answer 8

prevents tibia from moving forwards, prevents femur from moving backwards

Question 9

is the medial or lateral meniscus longer?

Answer 9

medial (c shaped)= longer!!!
lateral is o shaped= smaller!!!

Question 10

Menisci

Answer 10

• fibrocartilage
  -medial and lateral
  -attached to tibial plateau
  -attached to capusle by coronary lligaments
  -provides cushioning and stability
  -increases synovial fluid, circulation

Question 11

what does the quadriceps femoris do?

Answer 11

extends the leg at the knee, helps w PCL to prevent tibia from moving backwards

Question 12

what does the rectus femoris do?

Answer 12

helps w hip flexion

Question 13

Hamstrings: 3

Answer 13

semimembranosis
semitendinosis
biceps femoris

=flex lower leg on thigh at knee,
extend thigh on trunk at hip

Question 14

what does the hamstring do?

Answer 14

helps the ACL to prevent tibia moving forwards

Question 15

the last bit of knee locking comes from

Answer 15

tibia externally rotating, femur internally rotating

–> able to do this bc of length difference between medial and lateral tibial plateau
(medial condyle is larger than lateral)

Question 16

tensor fascia latae function

Answer 16

helps flex and abduct thigh on trunk at hip

adds lateral stability to knee

Question 17

gracilis help with

Answer 17

knee flexion

(same origin and insertion as semimembranosis, semitendinosis)

Question 18

3 types of bursae

Answer 18

prepatellar
suprapatellar (and fat pad)
infrapatellar (and fat pad)

Question 19

how does knee flexion and extension work?

Answer 19

gliding of condyles on plateau and menisci

Question 20

Knee Ax

Answer 20

pain, tenderness
snap or pop

observation:
limp, instability
swelling= intercapsular injury

ROM:
compare sides
thigh circumference
palpation

Question 21

knee alignment deviations

Answer 21

patellar malalignment

Q-angle= line between ASIS through patella and then a line between the patella through the tubercle

Genu valgum, genu varum, genu recurvatum, genu antecurvatum

Question 22

knee contusion (injury)

Answer 22

direct blow, worse if muscles relaxed

• no heat, no deep tissue massages (can increase bleeding)

Question 23

Weight bearing functional assessment

Answer 23

• Gait
• Squat
• Single leg squat
• Thessaly
• Duck walk
• 2 legged hop
• Single leg hop

Question 24

bursitis (injury)

Answer 24

direct blow or kneeling, overuse

-inflammation, tenderness
-heat, physio, rehab, police, padding, NSAIDs

Question 25

bursitis-- knee extension is painful if it is

Answer 25

infrapatellar or suprapatellar

Question 26

knee sprains Hx

Answer 26

direct blow (usually medial into valgus position)

Question 27

3 degrees of knee sprains

Answer 27

1st degree= mild pain, mild swelling 2nd degree= snap or pop, increased laxity, firm endpoint 3rd degree= snap or pop, swelling, soft endpoint

Question 28

meniscal tears

Answer 28

caused by torsion, hyperextension - acute= no surgery - free floating fragment of meniscus= arthroscopy

Question 29

capsular tears

Answer 29

caused by torsion, hyperextension - only seen on MRI - similar to meniscus tear SSx: pain, swelling, tenderness, rotary instability Tx: rest, physio, rehab, surgery

Question 30

patellofemoral pain syndrome

Answer 30

= paint around patellofemoral joint - overpronation, genu valgum, large Q angle contributes to abnormal patellar tracking

Question 31

chondromalacia patellae

Answer 31

= softening and deterioration of cartilage on the back of the patella tx: conservative!!! (police, decrease activity, activity modification, orthotics, strengthening)

Question 32

Patellofemoral Stress Syndrome

Answer 32

= Lateral tracking of patellae in femoral groove -tight musculature, weak hip abductors/stabilizers SSx: pain lateral patellae, crepitis with patellar compression Tx: POLICE, avoid aggravating activities, McConnell taping (keep patella in its groove)

Question 33

name the 3 acute traumatic knee injuries

Answer 33

1. patellar subluxation/dislocation 2. unhappy triad 3. osteochondritis dissecans

Question 34

what is the unhappy triad?

Answer 34

ACL tear, MCL tear, meniscal tear, capsular tear Tx: reconstructive surgery, brace, physio, rehab - more common in females

Question 35

what if you have effusion (collection of fluid) in an unhappy triad?

Answer 35

hospital asap!!!!

Question 36

osteochondritis dissecans

Answer 36

= damage to the cartilage and subchondral bone - cartilage is free floating - they drill into the bone which causes bleeding, can increase chondrocytes but also increases risk of osteoarthritis

Question 37

what do do for ACL (post surgical rehab)?

Answer 37

- quad/hamstring activation - ROM focusing on full extension - caution 3-4 months post-surgery - closed kinetic chain before open kinetic chain - strengthening (quads and hamstrings balanced) - 6 months: increase loads, jogging/running - neuromuscular training - RTP- technique, education - RTP- functional testing - brace? depends on athlete

Question 38

how to screen for risk of knee injury?

Answer 38

drop vertical jump test - are knees in line w toes as they land? if yes, good "knees kissing"= weak abductors, increased risk of ACL tear

Question 39

Ottawa knee rules

Answer 39

X ray for knee surgery if: 1. age 55+ OR 2. isolated patella tenderness OR 3. head of fibula tenderness OR 4. inability to flex 90 degrees OR 5. inability to weight bear for 4 steps (limping doesn't count)