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Flashcards in KOs and KAFOs Deck (52)
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1
Q

KO for A/P instability, M/L instability, Painful Arthritic knees

A

ADVANTAGES

Increases proprioception

Helps limit excessive rotation

Force Couple applied can unload knee joint space

DISADVANTAGES

Suspension

Difficult to ensure how much rotational stabilization is really taking place

2
Q

KO for Knee Hyperextension

A

ADVANTAGES

Knee joint limits knee extension

Can add lock mechanism

DISADVANTAGES

Suspension

3
Q

KO for Weak or absent quadriceps

A

ADVANTAGES

Knee lock stability
Extension assist for improved performance

DISADVANTAGES

Suspension

4
Q

KAFO designs

A

Conventional- metal and leather components

Plastic - metal uprights with plastic AFO and thigh sections

Hybrid - Combination of both

Hybrid

5
Q

KAFO Conventional Indications

A

Obese patient

Heavy users

Uncontrolled edema

6
Q

KAFO Conventional Contraindications

A

Need to conserve energy

Severe angular deformity

7
Q

KAFO Conventional Advantages

A

Decreased skin contact

More Breathable

Stronger

8
Q

KAFO Conventional Disadvantages

A

Heavy

Attached to shoe

Corrective pads and straps needed to control angular deformity at knee and ankle

9
Q

KAFO Plastic Indications

A

Knee instability

Genu recurvatum > 30 degrees, not controlled by AFO

Protection of Total Knee reconstruction

10
Q

KAFO Plastic Contraindications

A

Plastic - uncontrolled edema

Obese patient

Correction of severe angular deformity genu valgum/varum

Early spinal cord injury

11
Q

KAFO Plastic Advantages

A

LIghtweight

Cosmetic

Interchangeable shoes

12
Q

KAFO Plastic Disadvantages

A

Hot

Angular deformity should be first corrected

13
Q

KAFO Offset Free Knee Joint Indications

A

Unilateral paralysis

Near vertical hip and trunk alignment

Absence of knee flexion contracture

A plantargrade foot

14
Q

KAFO Offset Free Knee Joint Contraindications

A

Hip flexion contracture

Knee flexion contracture

Plantar flexion contracture

15
Q

KAFO Offset Free Knee Joint Advantages

A

Decreased energy expenditure

Sit/stand is easier

Stair ascend/descend in easier

More normal gait appearance

16
Q

KAFO Offset Free Knee Joint Disadvantages

A

Walking speed is restricted to advancement of swing leg

Ramps are out of the question

17
Q

KAFO Components

A

Distal tibial section similar to AFO

Proximal femoral section includes knee joints with proximal and distal thigh bands

Steel or aluminum uprights

Knee straps/pads

Weight bearing brim (if necessary)

18
Q

KAFO Accessories

A

Infrapatellar and supra-patellar straps help stabilize knee

Double knee strap (2D control, flexion and valgus control)

Ankle strap keeps foot in brace

Heel wedges to modify angle for balance

19
Q

KAFO Indicators

A

Unstable knee in flexion

Knee hyperextension

Medial/Lateral knee instabilities (Genu Valgum/Varum)

Axial unlaoding KAFOs (Ischial weight Bearing Brim)

Spinal Cord Injury

20
Q

KAFO Indicators - Unstable knee in flexion

A

Stance phase: weak pretibial and calf muscles along with weak quadriceps

Weak hip extensors require modified standing position in bilateral KAFOs

21
Q

KAFO Indicators - Knee Hyperextension

A

Indications for KAFO/KO when the knee hyperextension is greater than 15 degrees

KAFO is chosen if ankle weakness or KO suspension are problems

22
Q

KAFO Indicators - Medial/lateral knee instabilities (Genu Valgum/Varum)

A

Require 3PP systems to stabilize/correct leg

The longer the lever arm, the less force is required to stabilize/correct leg

23
Q

Axial unloading KAFOs(Ischial Weight Bearing Brim)

A

Gaol is to reduce the load taken on the distal apsect of the limb or reduce the load on the hip joint itself

Ischial weight bearing brims

  • Ischial ring
  • Ischial containment
  • Quadrilateral brim
24
Q

KAFO- Spinal Cord Injury

A

Hip flexion contractures than prevent full hip extension may prevent the paraplegic client from ambulating

Spasms will help allow client to stand even when their muscle strength is below normal

Few clients ambulate with lesions with lesions T2 or above

Lesions from T3 to T11 may use bilateral KAFOs for short distance for exercise

Craig Scott Orthosis

  • conventional design using offset knee joints with bail locks
  • there is no distal thigh band, only a proximal thigh band and anterior pretibial band
25
Q

Indications for Locked Knee

A

Upper extremity and trunk too weak or unstable to balance over the hip

Patient needs to lean back behind the knee joint to stabilize the hip

Hip and knee flexion contractures

Plantarflexion contracture

Bilateral lower extremity paralysis

26
Q

Ischial Weight Bearing Brims

A
  1. Ischial Ring (Thomas Ring)
  2. Ischial Containment Brim
  3. Quadrilateral Brim
  4. Patten Bottom with Ischial Brim
27
Q

Ischial Ring (Thomas Ring)

A

2 inch metal ring covered with leather and padding

Advantage- cool with small surface area
Disadvantage- small surface area provides limited support and creates high pressure on ischium

28
Q

Ischial Containment Brim

A

Custom molded or prefabricated shell contains ischium

Advantages- good rotation control and axial loading due to skeletal contours

Disadvantages- difficult to fit

29
Q

Quadrilateral Brim

A

Quadrilateral shape allow for the ischium to sit on the posterior ledge of brim

Advantages- easier to fit than ischial containment and good rotation control

Disadvantages- can be difficult to maintain ischial contact and prevent slipping off posterior ledge (Especially with hip flexion contractures)

30
Q

Patten Bottom with Ischial Brim

A

Foot floats in between uprights and above metal foot plate

Advantage- 100% unloading of the leg as foot does not contact ground

Disadvantage - cumbersome, raises the affected side

31
Q

Stabilization of flail knee without use of knee extension moment and free-knee joint

A

Off set free knee joint

Ankle in plantarflexion with maximum rigidity

32
Q

Stabilization of flail knee without use of use of knee extension moment and free knee joint

A

Off set knee with lock

Free knee with lock

33
Q

Prevention of Genu Recurvatum

A

Off-set free knee joint

Knee lock unnecessary in pure Genu recurvatum

Knee lock may be needed if G Recurvatum is associated with extensor weakness

Ankle in neutral or DF to prevent knee extension moment

34
Q

Reduction of Knee Flexion Contracture

A

Adjustable to correct contracture

35
Q

Control of Genu Valgum

A

Use of lock optional, dependent on severity of problem and associated deficits

36
Q

Control of Genu Varum

A

Use of knee lock optional, dependent on severity of the problem and associated deficits

37
Q

Free Motion

A

Function

Full flexion, 0 degree extension stop

Advantage

Full range of knee motion

Disadvantage

Cannot be locked

38
Q

Polycentric

A

2 axes move center of rotation closer to anatomical knee axis

Advantage

Better Knee motion

Bulky

39
Q

Off-set

A

Function

Free knee joint-inherently stable due to extension moment with joint position posterior to weight line of body

Advantage

Inherently stable for mild knee problems, good for hyperextension control

Disadvantage

Can’t guarantee knee staying extended all the time

40
Q

Off-set

A

Free knee joint-inherently stable due to extension moment with joint position posterior to weight line of body

Advantage

Inherently stable for mild knee problems, good for hyperextension control

Disadvantage

Can’t guarantee knee staying extended all the time

41
Q

Dial

A

Adjustable dial to change knee joint flexion/extension angles

Locking options available

Advantage

Ability to adjust knee angle after brace is made, good for knee flexion contracture

Disadvantage

Rachet teeth in dial can wear out faster than regular knee joints, especially after multiple adjsutments

42
Q

Drop (ring) locks

A

Rings around knee joint drop down automatically with gravity, but must be manually lifted to unlock

Advantages

Strong
Simple

Disadvantages

Requires 2 hands to unlock (not for hemiplegia)

Unlocking hard for spastic clients

Must have full knee extension range to work

43
Q

Cable Release Drop Locks

A

Cable attached to each side of drop lock allows the locks to be lifted at the same time

One hand can operate locks

Not as bulky as spring loaded bail lock

Difficult to unlock if leg does not have full extension

Must grab cable through trousers

44
Q

Spring lever (bail lock)

A

Automatic spring loaded lock, disengaged by manually lifting a rigid metal bar posterior to the knee

Advantage

Easy to open, unilateral or bilateral AKFO use

Can open by leaning against wheelchair

No bending at hip to unlock

Disadvantages

Bulky underneath trousers

If bilateral KAFOs, bails can catch each other

Wears faster than drop locks

45
Q

Stance Control Knee Joints Indications

A

Isolated quad weakness

Incomplete spinal cord injury

Polio/post-polio

CVA

Peripheral Paresis/Paralysis

Nerve Inflammation

Neurological Failures

Myopathies

MS or similar diseases

Must be able to initiate swing thru

Must have fair or better hip flexor strength

46
Q

Contraindications

A

Knee flexion contracture > 10 degrees

Central Paralysis

Hip flexion contracture

Hip muscular involvement

Poor Balance/Coordination

Weight-bearing orthosis

Uncorrectable Genu Varum/Valgum > 10 degrees

Significant cognitive impairment

47
Q

Stance Control Knee Joints General

A

Usually for isolated quad weakness

Most joints lock on initial contact with unlocking at terminal stance when dorsiflexion occurs in conjunction with extension moments at the knee

Most joints require hip extensor control in order to neutralize forces across the orthotic joint

48
Q

Examples of Commercially Available Stance Control Knee Joints

A

Ottobock Free Walk

Horton Technology Inc Stance Control

Horton Technology Inc Smart Knee

Filauer Swing Phase Lock System

Becaker Orthopedic UTX Swing KAFO

Becaker ORthopedic E-Knee (Broader application, patients with higher level of disability)

Ultraflex Systems Inc. Ultra Safe Step (Stroke Patients)

49
Q

Anterior/Posterior Subluxation of knee

A

Motion controlled with KO having good purchase of proximal and distal to knee with sufficient lever arms and contact through soft tissue to stabilize the knee

Generation II

Don Joy

50
Q

Osgood-Schlatter’s Disease

A

Pain can be relieved with infrapatellar strap to apply pressure at tibial tuberosity

Reduce motion and control tracking of patella as knee flexes and extends

Patellar stabilization knee sleeve also worn to decreased symptoms caused by patellofemoral conditions

51
Q

Compartment Pain

A

Medial or lateral compartment pain managed in KAFO or possibly Ko

Applies varus or valgus force depending upon diseased compartment

Suspension of KO not always possible

52
Q

Patellar Subluxation

A

Commonly controlled with neoprene or elastic knee sleeve having cut out for patella, sewn in buttresses that maintain patella in normal tracking position