ACTUAL Exam Questions and CORRECT
Answers
What are the 3 bones in the knee? - CORRECT ANSWER - - tibia
- fibula
- femur
what are the 3 joints in the knee? - CORRECT ANSWER - - medial tibiofemoral
- lateral tibiofemoral
- patellofemoral
Where is stress put in a valgus deformity? - CORRECT ANSWER - - lateral compartment
where is stress put in varus deformity? - CORRECT ANSWER - - medial compartment
what is the anatomical axis? - CORRECT ANSWER - - down the medullary canal of the
femur and tibia
what is the mechanical axis? - CORRECT ANSWER - - center of femoral head --> center
of knee --> center of ankle
- axis of weight bearing in the lower limb
What is the function axis? - CORRECT ANSWER - - where the knee rotates around
- flexion-extension axis
What are the 6 degrees of motion in the knee? - CORRECT ANSWER --
extension/flexion
,- varus/valgus
- internal/external
- medial/lateral
- anterior/posterior
- proximal/distal
What is femoral roll back? - CORRECT ANSWER - -allows for increased knee flexion by
avoiding impingement
-lateral side rolls back farther than medial side
What do the ACL and PCL help with? - CORRECT ANSWER - - anterior/posterior
motion
what do the MCL and LCL help with? - CORRECT ANSWER - - varus/valgus motion
- medial/lateral motion
What ligaments are usually sacrificed with a knee replacement? - CORRECT ANSWER -
- ACL (most often)
- PCL
why are the MCL and PCL not sacrificed in a knee replacement? - CORRECT ANSWER -
They play a more important role
- MCL = very strong
- LCL = weaker
What degrees of rotation does the tibiofemoral joint have? - CORRECT ANSWER --
flexion/extension = 0-135 (most important)
- varus/valgus = 6-8
- internal/external = 25-30
, Tibiofemoral position joint force - CORRECT ANSWER - - standing = equal BW
- swing phase = 1/2 x BW
- stance phase = 2-4 x BW
- jogging = 6 x BW
Tibiofemoral everyday mobility - CORRECT ANSWER - - walking = 67 degree of
flexion
- sitting = 83-110 degree of flexion (needed to do daily things)
- squatting = 130 degrees of flexion
what is the function of the patella? - CORRECT ANSWER - - acts as slippery surface for
tendon as it passes over front of knee
- increases mechanical advantage of quad muscles
- keeps the tendon from slipping off the side of the femur
Does the patella extend the moment arm? - CORRECT ANSWER - - Yes
- makes movement easier
What is the Q angle? - CORRECT ANSWER - The angle between the extended
anatomical axis of the femur and the line between the center of the patella and the tibial tubercle
What are the degrees of the Q angle for men and women? - CORRECT ANSWER -
flexion
- male = 13 degrees
- female = 18 degrees
extension
- 8 degrees