KAFOs - Knee Ankle Foot Orthoses

Conventional vs. Total Surface Bearing/Thermoplastic

p7-1Total Surface Bearing/Thermoplastic is always preferable due to increased control areas and the reduced pressures on the skin that results.  Therefore, the total surface bearing orthoses provides more comfort and better function than the conventional alternative.  Total Surface Bearing/Thermoplastic designs are also considerably lighter, have a better durability/weight ratio, are easier to clean, and can easily be chance to different shoes. 

 

 

 

 

 

 

 

p3-1Conventional KAFOs can be a valuable tool, however, they are generally a last resort behind Total Surface Bearing/Thermoplastic or hybrid designs.  Conditions that merit their use include conditions with fluctuating edema or fluid retention, or patient preference. 

 

 

 

 

 

 

 

 

Conventional

Indications

 

Contraindications

 

Advantages

 

Disadvantages

 

 

 

 

 

 

 

 

Total Surface Bearing/Thermoplastic

 

2005KAFOFront
Indications

 

Contraindications

 

MD sample ptAdvantages

 

Disadvantages

 

 

 

 

 

 

 

 

Other KAFO Designs

 

Hybrid KAFO

A hybrid KAFO combines the conventional type KAFO with the thermoplastic KAFO by having part of the brace be thermoplastic and part using a metal and leather type design.  This is usually indicated when an individual has a tendency for distal edema.  In this case, the proximal section of the brace can still provide advantages of a thermoplastic design while the distal section is made conventionally to allow for changing edema volume of the lower leg. 

 

Ischial Weight Bearing KAFO

The ischial weight bearing KAFO is either thermoplastic or conventional (although thermoplastic is superior due to total surface bearing and other advantages) and is standard in design distally but includes a proximal brim or ring.  This proximal brim is designed to transfer weight onto the ischium and thereby take weight off of the leg.  Another design consideration is that in order for this to be effective, the height of the KAFO should be slightly longer than the measurement of the ischium to the floor in normal standing.  Proper application of this design should take approximately 60% of the weight off of the lower limb. The ischial brim is traditionally a "quadrilateral shape" but more modern "Narrow M-L" type designs are also applicable.

 

Stance Phase Control KAFO

A stance phase control KAFO is the same as a standard KAFO design with the exception of the knee locking mechanism.  "Stance phase control" refers to a knee joint that is stable or will not buckle while in the stance phase of gait while still allowing for free knee flexion during the swing phase of gait.  This property allows for a much more normal walking pattern for someone who still needs support in keeping the knee from buckling.  The indications for this type of brace vary depending on what specific knee joint is used.    The following pages provide the different Stance Phase Control options that are available currently as well as a description of each knee's indications and contraindications. 

 

 

 

 

 

free_walk_1Otto Bock - Free Walk

FreeWalk Stance Control Knee/Ankle System

The FreeWalk KAFO revolutionizes the way your patients walk.
Our innovative design creates a more natural gait cycle by locking during stance phase and unlocking during swing phase. The automatic lock is initiated by knee extension, and is only released to swing freely when a knee extension moment and dorsiflexion occur simultaneously in terminal stance. The result is a more secure, efficient gait that also reduces the incidence of typical gait compensations.

FreeWalk 170K1=L/R-80 (fits 80 kg or 175 lbs)
FreeWalk 170K1=L/R-120 (fits 120 kg or 265 lbs)



Indications

Isolated quad weakness, polio, post-polio, MS, unilateral paralysis, incomplete spinal cord injury, trauma.

 

 

Horton Technology Inc. - The Horton SCOKJ

Designed for patients with weak or absent quadriceps and varying degrees of knee instability.  This lightweight orthosis will allow patients to regain their mobility and assist them in a more energy-efficient ambulation.  The Horton SCOKJ blocks flexion at any degree.
Prevents knee collapse regardless of flexion
http://www.stancecontrol.com/Mvc-red.jpgLightweight materials
High Durability

Indications:

Isolated quad weakness / absence
Unilateral leg paralysis / paresis
Increased stability for FR AFO candidates
Increased stability for offset knee KAFO wearers
Increased stability for free knee KAFO wearers
Increased stability for solid ankle / PF stop AFO wearers

Contraindications:

Total loading > 225 pounds /102k
Significantly impaired cognition, balance, or motivation
Uncorrectable Genu Varum / Valgum > 10 degrees
Knee flexion contracture > 10 degrees
Biological knee joint > 5 degrees off line of progression in
swing phase

The flexion lock is released automatically in late stance phase
by a mechanical linkage, either by reduction of heel weightbearing
or ankle motion. In addition to its automatic mode, the Horton
SCOKJ can be locked in full extension or always unlocked for
specific activities requiring those extremes.

For more info on this knee contact the following or contact Capstone Orthopedic to get one made!
www.stancecontrol.com
Info@stancecontrol.com
Horton Technology Inc.
Innovations In Orthotics and Prosthetics
5220 West 12th * Little Rock, AR. 72204

Basko Healthcare - Fillauer - The Swing Phase Lock (SPL)
The SPL uses a simple internal pendulum mechanism
to lock and unlock the knee depending on the angle of the joint in the sagittal plane.
During gait, the device locks just prior to heel strike for support during stance,
and unlocks the knee at heel off in preparation for swing. This action is
intended to mimic the normal physiologic action of the knee extensors.
Because the mechanism is position dependent, it does not rely on heel
loading or cabling as in other designs.

The SPL is intended for patients with partial
or total paralysis of the knee extensors and
2002-07_14_01can be used as a KO or KAFO, with or without
articulating ankle joints. It is not recommended
for those with more proximal impairment of the
hip musculature.  To use the SPL, the patient must be able to
initiate swing thru. If there is no active hip
extensor at heel strike, (hip extensor failure,
foot flexor failure) a dorsiflexion stop may be
used to help unlock the knee. Users must have
fair or better (grade 3) hip flexor strength to use
the SPL. Also, the SPL orthotic knee system
has been designed only as a non-weight bearing
joint and should not be used in any weight
bearing orthoses.

Contraindications:
- Knee Flexion Contracture
greater than 10 degrees
- Central Paralysis
- Hip Flexion Contracture
- Hip Musculature Involvement
- Poor Balance/Coordination
- Knee Hyperextension
greater than 10 degrees

The Swing Phase Lock has three modes of
operation controlled by a proximal remote
push-button switch:
1) Automatic Lock/ Unlock
2) Manual Unlock
3) Manual Lock
The different modes allow the patient to select
automatic lock for walking, unlock for sitting,
or lock for standing.

The SPL operates on a unique pendulum mechanism, which
rocks fore and aft in response to momentum and gravity. Just
before heel strike, the pendulum moves backwards, locking the
knee in extension for weight-bearing. At the
end of stance phase, the pendulum swings
forward again, releasing the lock to allow
flexion in swing phase. For additional patient
safety, an extension moment is required
both to lock and unlock the joint.

The UTX

Knee-Ankle-Foot Orthosis with Intelligent Knee Stabilization System

  • The UTX Swing Knee Ankle Foot Orthosis, was designed and developed by Dr. Nils Van Leerdam, of Ambroise Holland bv.
  • It is a lightweight 1.65 - 1.98 lbs (750-900 grams) KAFO that stabilizes the knee during the stance phase of gait but enables knee flexion during swing phase.
  • At the end of swing phase, as the knee reaches full extension, a ratchet engages to stabilize the knee.
  • A cable runs inside the distal side member from the ankle joint to the knee joint. At the end of stance phase as the ankle dorsiflexes, this cable linkage is used to unlock and destabilize the knee.

walk2

  

walk


Clinical Indications:

  • Quadriceps weakness as a result of Poliomyelitis, Multiple Sclerosis, CVA, Femoral Nerve and Spinal Cord Injuries.
  • Genu Recurvatum.
  • Successful users will typically have hip extensor strength (Power 3) and passive ankle dorsiflexon.

UTX Swing 80/120:

  • Body weight up to 80kg (175lbs) - UTX Swing 80
  • Body weight up to 120kg (265lbs) - UTX Swing 120

UTX Fs Swing for added Control in Coronal Plane:

  • The UTX Fs Swing is designed to control unstable genu valgum.
  • Body weight up to 100kg (220lbs)

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q

UTX Fs SWING

  

UTX SWING 80/120

The E-Knee
The "E-Knee", with the "E" standing for "electronic", joint represents the first practical marriage of the computer age with long leg braces. The E-Knee combines force plates and microprocessor technology to create a knee joint that locks and unlocks with foot contact on the floor. The locking mechanism is on the outside of the knee joint and is powered by a lithium battery. The joint also utilizes a unique clutch lock, which will lock in any position when triggered. The knee joint is linked to a footplate, which contains multiple sensors. Through a careful calibration process the foot-plate/knee joint mechanism is programmed to lock at the proper time, when the foot touches the ground. It is then further programmed to unlock the knee and allow for free swing as your gait cycle progresses.
Note that Becker Othopedic also has some other new and exciting options for orthotic knee joints including other stance phase control options.

http://www.beckerortho.com/knee/training.jpg