Knee examination

Question 1

In what general order should you perform the knee examination?

Answer 1

Look: Standing, gait, lying on bed

Feel

Move: Active, passive

Resisted movements

Special tests: Posterior sag sign, anterior draw

Question 2

How should you appropriately expose the patient to examine their knee?

Answer 2

Ask to wear shorts

Roll up trousers to mid thigh

Question 3

From what angles should you look at a patient’s knees when they are standing?

Answer 3

Anterior
Lateral
Posterior
Lateral

Question 4

From the anterior view, give examples of what you look for on the patient’s knees?

Answer 4

Symmetry, or any valgus/varus deformity

Bruising, erythema

Swelling (unilateral or bilateral) eg. inflammation, gout

Quadricep bulk and any wasting

Psoriasis plaques or other skin changes

Position of patella

Swelling of calf: DVT

Question 5

If there is asymmetry in the quadriceps bulk across the knees, what 2 pathologies can this indicate?

Answer 5

Disuse atrophy

Lower motor neuron lesion

Question 6

Where should the patella be located relative to the knee joint, and why might it be abnormal?

Answer 6

Patella should be in centre of knee joint

Could be patella dislocation/subluxation which commonly occurs due to falls, collisions, direct force to knee

Question 7

From the lateral view, what are the 2 main things to look for in the knees, and what can these abnormalities indicate?

Answer 7

Knee hyperextension: Usually due to ACL or PCL injury

Knee fixed flexion deformity: OA, contracture of hamstring muscles, inflammatory arthritis

Question 8

From the posterior view, what abnormalities should you look for?

Answer 8

Baker’s cyst: Cyst due to swollen and inflamed tissue behind knee, forms a fluid filled sac

Popliteal aneurysm: Usually pulsatile

DVT: one calf is larger than the other, erythema, warmth

Question 9

What are 4 signs of DVT?

Answer 9

Asymmetrical swelling of the leg or along a vein in the leg.

Pain or tenderness in the leg, which you may feel only when standing or walking

Increased warmth in the area of the leg that’s swollen or painful

Red or discolored skin on the leg.

Question 10

After you view the patient’s knees when standing, what should you look at next?

Answer 10

Gait

Question 11

After you look at the patient’s gait, how should you position them, and where should you look at patient from?

Answer 11

Ask patient to lie on bed on their back

Stand at end of bed

Question 12

When the patient is lying down, what knee abnormalities should you look for?

Answer 12

Symmetry, or any valgus/varus deformity

Bruising, erythema

Swelling (unilateral or bilateral) eg. inflammation, gout

Quadricep bulk and any wasting

Psoriasis plaques or other skin changes

Position of patella

Swelling of calf

Question 13

What is the first thing you should feel for in a patient’s knees, and why?

Answer 13

Palpate temperature below, surrounding, above knee joint
then compare with other knee

Higher temperature at knee joint can indicate infection, inflammation

Question 14

After feeling temperature of the extended knee, what should you feel around the patella?

Answer 14

Medial and lateral borders (stabilise the side that isn’t being palpated)

Medial and lateral joint lines

Medial and lateral collateral ligaments

Patellar and quadriceps tendon

Question 15

What does tenderness of the knee’s medial and lateral joint lines indicate?

Answer 15

Joint capsule tear or irritation

Meniscus tear

Chondromalacia patella: breakdown of cartilage on the underside of the kneecap (patella). When the kneecap rubs against the thigh bone, it hurts and swells

Osteochonritis dissecans: piece of bone and the attached cartilage break down and become loose

Septic, inflammatory arthritis, OA

Question 16

What does tenderness of the medial or lateral collateral ligaments indicate?

Answer 16

Tendonitis or rupture

Question 17

After feeling the extended knee, how should you reposition the knee to feel more landmarks?

Answer 17

Flex knee to 90 degrees

Question 18

What landmarks should you feel on the flexed knee?

Answer 18

Medial and lateral borders (stabilise the side that isn’t being palpated)

Medial and lateral joint lines

Medial and lateral collateral ligaments

Patellar ligament and quadriceps tendon

Question 19

How do you feel stability of the medial and lateral collateral ligaments of the knee?

Answer 19

With right arm, hold patients leg

With left hand, press on medial aspect of knee to test lateral collateral ligament (varus stress test)

Press on lateral aspect of knee to test medial collateral ligament (valgus stress test)

Knee should not move laterally if ligaments are stable

Question 20

Why is it important to feel flexed knee?

Answer 20

To feel posterior aspect for popliteal swelling in the popliteal fossa

Question 21

If you feel a pulsatile mass in the popliteal fossa of the flexed knee, what does this indicate?

Answer 21

Popliteal aneurysm

If its not pulsatile, it could also be a baker’s cyst

Question 22

When you feel the flexed knee, what 2 bony landmarks should you feel after the patella and popliteal fossa, and why?

Answer 22

Tibial tuberosity: If there is bony elevation and swelling, this can indicate Osgood-Schlatter disease

Fibula head: Tenderness associated with fracture

Question 23

How do you perform the cross-fluctuational bulge/sweep test in the extended knee?

Answer 23

Cross-fluctuational bulge test if there’s little fluid in the knee

1. Bulge of fluid in medial condyle area of knee
2. Squeeze fluid out from medial side of patella upwards around over superior patella border, down lateral side

Positive: bulge emerges in medial gutter of knee

Question 24

How do you perform the patellar tap test in the extended knee?

Answer 24

Patella tap to check if there’s any fluid in the knee joint (knee effusion)

1. Put hand above knee and squeeze downwards
2. Use thumb/fingers to push down on patella and check if patella bounces

Positive: sensation of patella hitting femoral condyle, which indicates presence of effusion

Question 25

How do you test active knee flexion?

Answer 25

Ask patient to flex (bend) knees as far as they can by bringing their heel as close to them as possible

(normal range 0-140 degrees)

Question 26

How do you test active knee extension?

Answer 26

Ask patient to straighten out their legs again so that they are flat

(normal range 180)

Question 27

How do you test passive knee flexion?

Answer 27

Hold calf with left hand, place right hand on knee joint to feel for crepitus whilst bending knee

Question 28

How do you test for passive knee hyperextension?

Answer 28

Hold above ankle joint, gently pull upwards

Normal angle 10 degrees

Question 29

What special test is used to indicate ACL laxity or rupture in the knee?

Answer 29

Anterior draw test:
1. Put fingers on hamstrings to check that they’re relaxed

2. Put thumbs onto tibial condyle
3. Use elbow to brace lower leg
4. Pull gently, observe patient’s face for any pain

Positive: feel large forwards movement of knee, which suggests that anterior cruciate ligament is lax or ruptured

Question 30

What special sign is used to indicate PCL rupture in the knee?

Answer 30

Posterior sag sign

1. Flex knee to 90 degrees
2. Observe knee from side, tibia can sag posteriorly in relation to the femur

This indicates rupture of posterior cruciate ligament

Question 31

What special sign is used to indicate PCL laxity or rupture in the knee?

Answer 31

Posterior draw test