Knee Orthoses and KAFO's types

Question 1

varus or valgus control?

Answer 1

valgus control

Question 2

valgus or varus control?

Answer 2

varus control

Question 3

name each number

Answer 3

1. Shell
2. Uprights
3. Straps

Question 4

disadvantages of single axis KAFO

Answer 4

mechanical and anatomical axis do not match (mechanical does not roll and slide) → creates stress

Question 5

Answer 5

polycentric hinges

better axis of rotation, but heavier and can break

Question 6

KAFO knee joint alignment types

Answer 6

1. in-line
2. Off set: axis posterior to the uprights
   
   • GRF is anterior to axis of rotation
   • produces extension moment

Question 7

drop or gravity locks

Answer 7

• Locks in extension
• Need to be manually unlocked:
  
  • UE strength and balance control
• May have a high level release ring

Question 8

pawl lock with bale release

Answer 8

• same as with the gravity lock, but with a larger unlocking system
• locks in extension
• unlocks when bale is pulled upwards
• can be unlocked with the edge of the seat
• can be mistakenly released during gait

Question 9

step / ratchet lock

Answer 9

• Allow motion into extension, sound heard
• Locks every certain amount of degrees to prevent flexion as patient moves into stance
• Manual release mechanism

Question 10

variable motion system

Answer 10

• Post surgery (ACL repair)
• Can set ROM
• Allows for function and protection

Question 11

weight activated knee joint AKA Stance Control Knee Ankle Foot Orthosis (SCKAFO)

Answer 11

• automatically allows knee flexion during swing
• prevents knee flexion during stance
• becomes unlocked due to position of GRF and ankle ROM (no electronics)

Question 12

computerized knee

Answer 12

• foot plate signals
• prevent knee buckling
• expensive, heavy
• not seen much

Question 13

types of knee orthoses

Answer 13

• functional
• rehabilitative
• unloaders
• supportive
• Supportive &/ or functional also used to try prevent injury

Question 14

Functional knee orthoses

Answer 14

• jointed or unjointed
• provide support for ligamentous laxity
• allows free flexion and extension
• they slip with mvmt

Question 15

Swedish knee cage

Answer 15

• functional knee orthoses
• post CVA: no quadriceps control yet. Temporary!
• no moving parts
• prevents knee from hyperextending

Question 16

Rehabilitative knee orthosis

Answer 16

• post knee injury or Sx
• adjustable ROM

Question 17

unloader knee orthoses

Answer 17

Question 18

indications for supportive knee devices

Answer 18

• Patellofemoral syndrome
• patella subluxation
• infra-patellar tendonitis

Question 19

true or false: the literature shows that supportive knee orthoses devices have a significant biomechanical effect

Answer 19

false, have no biomechanical effect,
but have a big psychological effect