Patellofemoral Joint

Question 1

1. What type of joint is the patellofemoral joint?

2. What are the 3 main functions of this joint?

Answer 1

1. sesamoid
2. transmit force of the quads to the tibia; increase the angle of pull of the patellar tendon; assist prevention of anterior femoral shear in w/b.

Question 2

Describe the tracking of the patella on the femur from full extension to full flexion.

Answer 2

full extension: no contact of patella on femur
10 degrees: contact on inferior margin of patella
as knee flexes, contact increases in area and moves superiorly.
90 degrees: Contact area is made at superior pole of the patella.
135 degrees (full flexion): contact with the odd facet (medial margin) is made.
See Magee pg 729 for more detail.

Question 3

1. What muscle pulls directly superior on the patella?
2. What muscle pulls slightly medial but mostly superior on the patella?
3. What muscle pulls more medial and superior on the patella?
4. What muscle pulls supero-laterally on the patella?
5. What other structure also pulls on the lateral side of the patella?

Answer 3

1. Rectus Femoris
2. Vastus Intermedius
3. Vastus Medialis Oblique
4. Vastus Lateralis
5. Iliotibial band.

Question 4

When doing an exam on the patellofemoral joint, what 4 areas of the body need to be examined?

Answer 4

1. Ankle/foot (pronation creates internal LE rotation, supination limits IR)
2. Knee (duh)
3. Hip (Weakness of ER and abductors = loss of ability to resist IR and adduction forces).
4. Low Back

Question 5

During the history portion of an exam, what locations of pain and painful activities will the patient report that may indicate patellofemoral problems?

Answer 5

Location: anterior knee pain, usually prepatellar or infrapatellar
Activities that cause pain: walking, running, stairs (especially going down), sitting for long periods.

Question 6

1. What is the term used when the patella tendon length > patellar length?
2. What is the term used when the patella tendon length < patellar length?

Answer 6

1. patella alta

2. patella baja

Question 7

What are the 3 weight bearing tests used during a patellafemoral exam? What are you looking for in all 3 of them?

Answer 7

Double Squat
Single Squat
Step up and Step down
Watch for symmetry differences from side to side at the hip, knee, and ankle.

Question 8

What are 6 areas that you should check during the strength testing portion of a patellofemoral exam?

Answer 8

Hip Flexion Strength (MMT)
SLR endurance
Hip Abduction Strength (MMT)
Abduction endurance
Hip ER and IR (MMT)
Squat Strength (isokinetic)

Question 9

Is there any research to support the McConnell Method? What does McConnell say the VMO/VL ratio should be? Why is this stuff in our notes?

Answer 9

no research. 1/1. No idea.

Question 10

What directions do you need to test when testing the mobility of the patella?

Answer 10

Superior/Inferior Tilt (Grab patella and pull up and press down)
Medial/Lateral Tilt
Medial/Lateral Glide

Question 11

1. What is the Q angle?
2. What are normal Q angles in males and females?
3. Above what Q angle is PFPS associated with?
4. What conditions/deformities are associated with an increased Q angle?

Answer 11

1. Angle from ASIS to center of patella to center of tibial tuberosity.
2. Male: 13 degrees. Female: 18 degrees
3. Angles >18 associated with PFPS.
4. Chondro-malacia patella, subluxing patella, increased femoral anteversion, genu valgum, lateral displacement of the tibial tubercle, and increased lateral tibial torsion.

Question 12

What 7 special tests should be done with a patient with PFPS?

Answer 12

Hamstring Flexibility
Gastrocnemius Flexibility
Ober Test
Thomas Test
Patellar Grind Test
Eccentric Step Test
Step Up Test

Question 13

How would you perform a patellar grind test? What is a positive patellar grind test?

Answer 13

Resist superior glide of the patella during a quad set by putting the web space of your hand on the superior margin of the patella. Positive is more pain in one side than the other.