chapter 18 knee

Question 1

define the Patella

Answer 1

Triangular-shaped sesamoid bone

Within quadriceps muscle tendon

Broad superior border

Distally somewhat pointed

Question 2

explain the weight-bearing activity (closed chain)

Answer 2

Posterior glide of femur results in femur rotating medially on the tibia

Tibia fixed and proximal component moves

Occurs last 20 ◦ of extension

Question 3

define the function of the patellofemoral

Answer 3

Increases mechanical advantage of quadriceps muscle
Protect knee joint

Question 4

explain the function of the q angle

Answer 4

from tibial tubercle to the middle of the patella
from the middle of the patella to the ASIS
Normal angle ranges
13-18°
Q angle > in females

Question 5

what is the q angle define as

Answer 5

angle between the rectus femoris muscle and the patellar tendon

Question 6

Angle < than 13 degrees associated with

Answer 6

Chondromalacia patellae

Question 7

Angle > 19 degrees associated with

Answer 7

Chondromalacia patellae
Subluxing patella
Genu valgus
Tibial torsion

Question 8

what is normal range of tibial - femoral angle

Answer 8

Normal ~ 165 - 180 ◦

Question 9

define Genu Valgus

Answer 9

less than 165

Question 10

define genu varum

Answer 10

grater than 180

Question 11

the origin and insertion of the AC L

Answer 11

Attaches to the anterior surface of the tibia in the intercondylar area just medial to the medial meniscus

Runs superior and posterior
Attaches posteriorly on the lateral condyle of the femur

Question 12

the origin and insertion of PCL

Answer 12

Attaches to the posterior tibia in the intercondylar area

Runs superior and anterior
Attaches to the anterior femur on the medial condyle

Question 13

the function of ACL

Answer 13

Prevents anterior tibial displacement on femur and posterior displacement of femur on tibia

Tight during extension

Question 14

the function of PCL

Answer 14

Prevents posterior tibial displacement on femur / anterior displacement of femur on tibia

Tight during flexion

Question 15

A patient’s foot is planted on the ground. They were hit by a force to their anterior femur which pushes the femur posterior. Which cruciate ligament is most likely to be torn in this scenario?

Answer 15

the ACL, when the force hits the anterior femur and pushes it posteriorly, it will stretch the ACL as the femur moves posteriorly

Question 16

define the medial collateral ligament

Answer 16

Flat, broad ligament

Attaches to medial condyles of femur and tibia

Attaches to medial meniscus
May see associated injuries

Protects against lateral stress

Question 17

define the the lateral collateral ligament

Answer 17

Round, cordlike ligament

Attaches lateral condyle of the femur and runs down to the head of the fibula

No attachment to menisci

Strong, seldom injured

Protects against medial stress

Question 18

what are the both functions of collateral ligaments

Answer 18

Provide stability in the frontal plane

Tight during extension

Slack during flexion

Both ligaments posterior to knee axis

Question 19

If a patient was standing or running and they were hit by a force to the lateral aspect of their tibia with their foot planted, which collateral ligament would most likely be torn?

Answer 19

The medial collateral ligament – because it is put on stretch with the above type of force.

Question 20

what are the functions of the menisci

Answer 20

Purpose:

Shock absorption

Deepen the joint surface
Thicker laterally

Proximal surfaces are concave

Question 21

what are the menisci

Answer 21

Two half-moon, wedge-shaped fibrocartilage disks – do NOT have a blood supply

Question 22

knee closed pack what movement is the tibiofemoral

Answer 22

full extension with tibial lateral rotation

Question 23

knee closed pack what movement is the patellofemoral

Answer 23

full flexion

Question 24

knee open pack what movement is tibiofemoral

Answer 24

25 degrees flexion

Question 25

knee open pack what movement is patellofemoral

Answer 25

10-20 flexion