Ortho Prosthe KAFO PDF

Preview

Summary

Orthosis-Prosthesis- different types of knee ankle foot orthosis with pictures...

Description

2nd Semester, S.Y. 2016-2017

ORTHOTICS & PROSTHETICS TOPIC Lecturer References

OUTLINE I. II.

III. IV. V. VI.

Date

ORTHO-PROSTHE KAFO Dra. Carmina Anne Jerez-Cortez PPT, NYU, Manual

Introduction KAFO Designs a. Leather Metal KAFO b. Plastic Metal KAFO Knee Joints & Locks Accessory Pads and Straps Desired Variations Knee Orthosis

2 principal Polycentric Designs consist of:  Two meshing gears – provides a fixed path of rotation.  A Plate with 2 pivots (genucentric) - moves along a path which adapts to the changing center of motion of the anatomic knee Plastic Metal KAFO  

Introduction 

When AFO is extended proximally to include the knee joint, it becomes a KAFO & adds control of knee motion and alignment.

It has plastic shells & metal uprights that are attached by screws or rivets If there is a circumferential growth or increasing limb volume it is address by spot heating and reshaping the thermoplastic.

Indication for Plastic design KAFO:  A close fit and precise control of pressure are important  Maximum control of the foot is desired  Lightness, improved appearance, or the nonabsorbent properties of plastic are important Thigh Shell  Provide greater support & control the corresponding segment.  Proximal contours of thigh shells normally are quadrilateral in shape to help control rotation.  May incorporate as ischial seat if weight-bearing is intended.  There is a forward clearance for the foot to pass through the thigh shell during donning of the orthosis. Knee Joints & Locks

Leather Metal KAFO 



A.

Single axis /Free motion knee joint  Most commonly used knee joints  It facilitate angle movement in sagittal plane  Flexion/extension (nothing will hold the knee in extension/flexion)  Allows unrestricted flexion and extension but ordinarily incorporates a stop, which prevents hyperextension.  Indication: for the individual who has sufficient muscle power to control the knee during WB & walking but has a tendency toward recurvatum or mediolateral instability.

B.

Offset knee joint  The mechanical axis is located posterior to the uprights.  No stress to be in the knee joint  It can be move slightly in anterior or posterior direction  It tends to extend in early stance, because its axis is posterior to the floor.

It has 2 uprights, that extend up the thigh & includes the mechanical knee joint and 2 thigh bands. Anatomical knee joint has changing axis of rotation, mechanical joints with fixed axis cannot move in complete unison with it.

Polycentric Joints  Follows the natural motions of the knee joint more accurately  Indicated only when significant knee motion is to be permitted during walking.  Use more frequent in knee orthoses than in KAFO’s

Trans by: MGC & IMB

1

2nd Semester, S.Y. 2016-2017





C.

Knee is relatively stable without a lock, but is free to bend during swing & allows sitting without the need to manipulate locks. Indication: cannot be used with knee or hip flexion contracture, or with a plantar flexion stop at the ankle.

Drop Ring Lock  Most commonly used knee lock to control flexion.  It is a simple, effective and sturdy but may bind in the presence of knee-flexion contractures or spasticity.  The ring drop over the joints by gravity or with manual assistance when the uprights are fully extended.  Holds knee in extension to lock the knee when Pt’s stands.  Indication: For the Pt who is capable of walking with a free knee but may wish to lock it occasionally.

Spring-loaded Retention Buttons o Can be included to prevent the rings from dropping inadvertently. o It assists sitting, since the patient can raise one lock above the button & still have adequate stability to grasp the chair with one hand while raising the other lock with the free hand. Spring Loaded Pull Rod o It extends to mid-thigh level & may be placed to the ring so that the wearer doesn’t need bend to lock or unlock the joint. o It recoils to drive the ring lock down, assisting gravity in locking the knee o Used only for unilateral upright. D.

Polycentric Knee Joint  It allows little rotation around the knee

E.

Pawl Lock  Use because it is easier to release than the ring lock when a flexion force exists at the knee joint.  It consists of a spring-loaded pawl that fits into a matching recess when the knee joint is fully extended and locks the knee  Flexion forces are exerted on the knee joint, this lock is easier to release than drop lock.  A ball or a semicircular lever unlocks the pawl simultaneously & allows unlocking by a manual upward pull or by catching the bail on the edge of a chair.  In the absence of springs, elastic webbing from the ball to the calf band must be used (Swiss or French lock)

F.

Adjustable Knee Lock  Indication: For Pt who wants changes in his condition such as gradual stretching of a knee-flexion contracture.  Fan lock - incorporate a drop-ring lock that maintains the desired knee position in standing and walking, but can be unlocked to permit full knee flexion when sitting.

G.

Serrated Adjustable Knee Joint  Permits locking in any degree of flexion at 6-deg. intervals.  Proximal portion is a single-axis joint with a drop-ring lock, but the distal portion consists of an outer ring with internal serrations matting with the external serration of an outer disc.  It allows very precise control of flexion, the center of adjustment is approximately 4 cm. (1 ½ inch) below the single-axis joint

H.

Bale Lock  Can control amount of flexion that the knee joint can have  Contains notches to adjust the amount of flexion that the knee can have  Indication: For contractures or spasticity

Otto Bock Free Walk/Becker Orthopedic UTX  Spring-loaded pawl locks knee when full extension is attained  Dorsiflexion of foot at the end of stance pulls on control cable connected to pawl to disengage lock for swing

Pawl Lock

Trans by: MGC & IMB

2

2nd Semester, S.Y. 2016-2017

Accessory Pads and Straps Knee cap  Used to prevent uncomfortable contact between the limb and the orthotic cuffs.  Placed in front of the knee & secured around the uprights with straps.  Medial or Lateral Strap o Used if Pt has genu valgum and varum deformity. o Included in knee cap which buckles around one upright & pulls the knee towards that upright that provides a corrective force as required.

C.

Supracondylar Knee-Ankle-Foot Orthosis  Very durable because of its unitary construction & absence of mechanical parts.  It applies forces that resists recurvatum & provide mediolateral stability.  Distal portion limits subtalar motion & immobilizes the ankle in slight equinus so that a knee-extension moment is produced when forefoot is in contact with the ground.  Proximal portion protrudes above the knee when the wearer sits  If there is knee-extensor weakness, the application of this knee-stabilizing principle eliminates the need for a mechanical knee lock during stance phase and permits knee flexion during swing.  It cannot be used bilaterally, since positioning both ankles in equinus interferes with the Pt’s anteroposterior stability.  Conventional Metal Knee Joints o To alleviate the problem of protrusion above the knee during sitting, a variation of the supracondylar knee-ankle orthosis includes & uprights which allows the orthosis to flex at the knee while sitting.

Desired Variations A.

B.

Single Upright Orthosis  One design modification of the typical KAFO where the medial upright is eliminated.  It has thigh and pretibial cuffs made of molded plastic.  The other components are essentially the same as on double-upright orthoses. Scott-Craig Orthosis  Indication: Used for standing & ambulation in patients with paraplegia due to SCI  Designed to help SCI patients to stand and walk with 10˚ of ankle dorsiflexion alignment, it allows a swing-to or swing-through gait with crutches.  Provides orthotic stabilization of the knee, ankle and foot.  It consists of the ff: o Double uprights o Knee joints with pawl locks & bail control o One posterior thigh band o Hinged pretibial band o Ankle joint o Anterior and posterior adjustable pin stops o Cushion heel o T-shaped foot plate for mediolateral stability  The orthosis and the patient’s limb thus lean forward slightly.  The hinged pretibial band facilitates donning and doffing.

Trans by: MGC & IMB

Knee Orthosis Articulated knee orthosis 1. Post-surgery knee orthosis – protects repaired ligaments 2. Functional knee orthosis – in lieu of surgery or during selective activities to complete rupture or breakdown of ligament

3

2nd Semester, S.Y. 2016-2017

Swedish Knee cage  Mild control for excessive hyperextension  It will not allow your knee to flex

QUIZ

1. What knee problem does this patient has? (Genu valgum)

This patient would benefit most with what kind of orthosis? (Swiss lock)

Patellar stabilizing braces  Improve patellar tracking; maintain alignment

What is the problem of this patient? (patellar dislocation) What part of the knee orthosis should be present for this patient? (patella stabilizer) This type of lock will improve the knee’s stability in what position? (knee extension)

Neoprene Sleeves  Place along lower leg in the calf area  Provide compression, protection and proprioceptive feedback  Retains body heat  Use to increase temp. for performance  No stabilization unless with hinges  Use for recovery after a run  It doesn’t control the flow of blood

ADDITIONAL NOTES:  The location of upright is in the weak side  The closure is towards the correction Trans by: MGC & IMB

4...