Knee Exam

Question 1

Most commonly injured joint in body

Answer 1

Knee

Question 2

Most common site of symptomatic osteoarthritis

Answer 2

Knee (since the mid 70s)

Question 3

Describe knee joint

Answer 3

giant hinge w/ a twist

Question 4

Menisci provide

Answer 4

additional shock absorption and smoothly distribute the forces across the joint (and also provide some stability)

Question 5

Collateral ligaments provide

Answer 5

side-to-side stability

Question 6

Cruciate ligaments provide

Answer 6

front to back stability

ACL prevents tibia from sliding anteriorly on femur
PCL prevents tibia from sliding posteriorly on femur

ACL in front and goes lateral to medial, PCL is the opposite

Question 7

Femoral condyles provide

Answer 7

smooth rolling surface for the cup-shaped tibial plateau

Question 8

What happens as knee swings into terminal extension

Answer 8

tibia “screws home” (actually externally rotates) on the
femur, which allows increased stability as the knee
locks into full extension.

But rotation also predisposes the knee to injury. Excessive rotation of the knee can predispose to meniscus tears, to cruciate ligament injury, and to patellofemoral pain

Question 9

what does knee examination revolve around

Answer 9

palpation (but first take a history)

Question 10

why is history important

Answer 10

determine if knee is acutely injured or it isn’t AND determine if there is effusion or no effusion

Question 11

Overuse (non-acute) injuries are characterized by

Answer 11

vague pains, increased pain with increased activity, and often, a history of recently increased physical activity.

Question 12

Mensicus tears are far more likely to occur in which part?

Answer 12

Posterior horns (medial one in particular is most common)

McMurray test grinds and pinches posterior horn

Question 13

what to palpate on lateral joint line

Answer 13

anterior horn of the lateral meniscus, the lateral collateral ligament, and the posterior horn of the lateral meniscus

Question 14

Where do collateral ligaments tear?

Answer 14

femoral or tibial attachments (NEVER IN MIDDLE)

Question 15

what to palpate on medial joint line

Answer 15

anterior horn of the medial meniscus, the medial collateral ligament, and the posterior horn of the medial meniscus

Question 16

what to palpate on popliteal fossa

Answer 16

lateral hamstrings tendon: biceps femoris

medial hamstrings tendon: semitendinosis (round) and semimembranosus (broad and flat like a membrane)

for basker’s or popliteal cyst (usually caused by miniscus tear, cartilage damage, or arthritis)

Question 17

what to palpate off joint line

Answer 17

pes anserine bursa (about 2in inferior to anterior horn of medial meniscus)
lateral femoral condyle
IT band

Question 18

what structures have a bursa that may get irritated

Answer 18

pes anserine

IT band

Question 19

what to ask in history

Answer 19

Key elements
 Mechanism of injury
 Acute traumatic, overuse, or spontaneous onset
 Pop or tear with injury
 Location of pain
 Swelling (Y/N), if yes how long after injury
 Knee clicking, catching, or locking
 Give—way episodes
 Provoking/alleviating factor
 Effect on pt’s normal level of activity
 Past Medical/Past Surgical History

Question 20

what to inspect

Answer 20

Inspection
 Observe gait: normal, limping (antalgic), shuffling, or won’t walk
 Swelling
 Ecchymosis/ bruising
 Atrophy
 Alignment: Varus or Valgus

Question 21

Range of motion to test

Answer 21

 Flexion (active and passive)

 Extension (active and passive)

Question 22

Strength and neurovascular to test

Answer 22

 Flexion (active and passive)
 Extension (active and passive)
 Sensation
 Distal pulses (dorsalis pedis & posterior tibial)

Question 23

Special tests

Answer 23

Assess for Effusion
 Warm-Cold-Warm
 Milking Effusion/Fluid wave

Meniscus tear Tests
 McMurray’s
 Thessaly Test

Ligamentous tests
 Anterior drawer AND Lachman's (ACL)
 Posterior drawer (PCL)
 Varus stress (LCL)
 Valgus stress (MCL)

Patellar tests
 Patellar compression
 Patellar shrug pain
 Patellar apprehension
 Tenderness of patella facets

Question 24

What to look for in McMurray’s and Thessaly tests

Answer 24

pain or pop in medial or lateral joint line

**In McMurray’s heel points to the meniscus being tested

Question 25

Which test is most sensitive for ACL injury

Answer 25

Lachman’s test

more sensitive means you will have fewer false negatives (high proportion of TP)

Question 26

what to look for in Lachman’s test

Answer 26

Intact ACL feels like you are snapping the chain between two nunchucks.
A torn ACL has no discrete endpoint and allows more motion than the uninjured side

Question 27

+ Varus/Valgus stress tests

Answer 27

Pain or difference in laxity from side to side can indicate collateral ligament injury

Question 28

Over 70% of knee pain visits in the military are for

Answer 28

patellofemoral pain

Question 29

what to palpate for patellar exam

Answer 29

Tibial tuberosity (this is the bump on the anterior tibia where the patellar tendon attaches to the tibia)

Patellar Tendon (attaches the quadriceps muscle (via the patella)to the tibia)

Patella

Question 30

what to think if knee is not cold to touch

Answer 30

effusion (warm) or infection (hot)