Orthotics &prosthetics

Dr. Guru Prasad

DNB orthopaedics

Orthosis

• Definition

• Nomenclature

• Ideal characteristics

• Function

• Biomechanics

• Materials

• Complications

• Common orthotics

Definition

• An orthosis is a device that is externally applied to a body segment and that facilitates or improves function by supporting ,correcting or compensating for skeletal deformity or weakness

3500BC An Indian poem, Rig-Veda, is the first recorded document abouta prosthesis. The poem tells the tragic story of Queen Vishpla, a warrior, who losther leg in battle. After the battle, she had an iron prosthesis made, and she was able togo back to battle. TheRoman general named Marcus Sergius guided his troops against Carthage in the Second Punic War and sufferedover 20 injuries, including the loss of his right arm. An iron hand was created so that he could fight for the rest ofthe war.1st C BC Archeologists discovered bronze peg prosthetic. Although it was rusted, it is the oldest usable artifact of aprosthetic.1508 The German knight Götz von Berlichingen (1480-1562) . He had to have his right arm amputated after theBattle of Landshut. Gotz had two prosthetic iron hands to replace his right arm.1529 Ambroise Pare introduced amputation to the medical community. He is considered the father ofprosthetics. In 1536, he made an artificial limb for the arm and elbow and created other limbs later.1696 Pieter Andriannszoon Verduyn, a Dutch Surgeon, developed the first non-locking prosthesis for below theknee. This is the basis for the current joint and corset prosthesis.1843 Sir James Syme described his method for ankle amputation. Before this procedure, the technique usedamputated at the thigh. By amputating at the ankle, the patient could have the possibility to walk again. Thelonger leg length allowed an artificial foot to bear a typical weight[2], [3], [4], [5].

nomenclature

• Traditionally

part of body place person

• Knee brace milwakee brace dennis brown splint

• AAOS nomenclature

1st joint or region it encompasses

2nd biomechanical analysis of its function

Joint or region it encompasses

• FO = foot orthosis

• KAFO = Knee- ankle-foot orthosis

Biomechanical analysis of its function

F Free motion allowed

A Assist

R Resist

S Stop

H Hold

L lock

Ideal characteristics of orthotics

• Biomechanically effective• Light weight• Durable• Cosmetically pleasing• Easy to put on(DON) and put off (DOFF)• Inexpensive• Washable• Adjustable• Comfortable• Free from pressure areas

Functional characteristics of orthotics

• Provision of support

• Limitation of motion

• Correction of deformity

• Assistance in motion

• Miscellaneous

• Combination of all

• Provision of support- prevent weak muscles or ligaments

being stretched

- support joints

• Limitation of motion

- KO prevents hyper extension

• Correction of deformity

- dennis brown splint

• Assistance in motion

• - HKAFO to aid walking in myelomeningocele

Miscellaneous

- warmth ,placebo

• Combination

• - KAFO for polio leg gives support ,limits motion help correct varus ankle, assist ankle dorsiflexion

classification

• Static - has no moving part- to immobilize

• Dynamic - has moving part - movement controlled by energy store

eg rubber band- prevents muscle stiffness, muscle wasting - hastens repair of bone, tendons , ligaments

Basic biomechanical concept

• Three point principle – by Sir John Charnley

• Newtons third law

• Ground reaction force (GRF)

• Forces and moments

• Total contact.

• Partial weight relieving.

Three point pressure• "The sum of the forces and the bending

moments created is equal to zero.“

• A single force is placed at the area of deformity; two additional counter forces act in the opposing direction.

• During "quiet" standing, line of gravity (weight line) passes through:

– posterior to hip joint

– anterior to knee joint and

– anterior to ankle joint

Partial weight relieving• “The farther the point of force from the

joint, the greater the moment arm and the smaller the magnitude of force required to produce a given torque at the joint.”

• The greater the length of the supporting orthotic structure, the greater the moment or torque that can be placed on the joint or unstable segment.

Total contact

• “Pressure is equal to the total force per unit area. “

• The greater the area of a pad of an orthosis, the less force will be placed on the skin.

• P = force

Area of application

Biomechanics

• Direct

- Control of > moments

> translation forces

> axial forces

• Indirect

- control of > line of action of GRF

Materials

• Traditionally

• - rubber, leather, metal, POP

• Now-in-use

• > Thermosetting plastics

• > Thermoforming plastics

• > self generating polyurethane foam

Common orthoses

Foot orthoses

• Insoles

• Shoes

• Insoles

> simple

> total contact insoles

> functional /biomechanical

shoes

External modifications

Heel sole

Internal modifications

Heel Sole

Cushioned FlaredWedgedExtendedelevated

Rocker barsMetatarsal barsWedgesflares

Cushion reliefCupsUcbl inserts

Metatarsal padsInnersole excavationsArch supports

Ankle – foot orthoses

• Plastic AFO

• Posterior leaf AFO

• Solid AFO

• Hinged AFO

• Ground reaction AFO

• Dynamic AFO

• Metal plastic AFO

AFO• Ankle-foot orthosis is a brace, usually

plastic, worn on the lower leg and foot to support the ankle, hold the foot and ankle in the correct position, and correct foot drop.

• Purpose:

– To control alignment and motion of the joints of foot and ankle.

– For patients affected with muscular dystrophy, cerebral palsy, etc.

• Construction:

– Consists of a shoe attachment, ankle control, uprights and a proximal leg band.

• Parts:

– Calf bands

– Metal uprights

– Ankle joint

– Shoe attachments

– Stirrup

Calf band

Metal upright

Ankle joint

Shoe attachments

Stirrup

Floor Reaction Orthosis

Posterior leaf AFO Dynamic AFO

Hinged AFO

Metal plastic

Knee – ankle – foot orthoses

Knee Ankle Foot Orthosis (KAFO)

• A KAFO is a long-leg orthosis that spans the knee, the ankle, and the foot in an effort to stabilize the joints and assist the muscles of the leg.

• Material for fabrication: metals, plastics, fabrics, and leather.

• Used in quadriceps paralysis, maintain knee stability, control flexible varum/valgum

Parts

Hip joints and locks

• Controls for abduction, adduction and rotation.

• Controls for hip flexion when locked.

• 2 position hip locks are also available.

• Pelvic band

• To stabilize the hip joint.

• There are two types unilateral pelvic band and bilateral pelvic band.

• It adds weight and increases overall energy expenditure during ambulation.

Types of knee orthosis• Dynamic patellar orthosis:

• It consist of an elastic sleeve with patellar cutout.

• Its purpose is to prevent the dislocation of patella.

• Traditional knee orthosis

• It consists of leather thigh, calf cuffs and metal side bars.

• Pressure pad may be applied to generate medial or lateral forces.

• Swedish knee cage

• It used in the management of knee hyperextension.

• Two anterior pads and adjustable posterior pressure pad at the attachment to the upright .

Types of knee joints

• Free motion knee joint:

allows unrestricted flexion & extension.

• Off-set knee joint:

the hinge is located posterior to the knee joint stabilize knee during stance.

Hip Knee Ankle Foot Orthosis (HKAFO)

• Hip joint and pelvic band attached to the lateral upright of a KAFO converts it to a HKAFO.

• Purpose:

– Hip flexion/extension instability

– Hip adduction/abduction weakness

– Hip internal rotation/external rotation instability

• Parts:

– Sole plate extending to the metatarsal heads with a crossbar added to the metatarsal heads area for mediolateral stabilization.

– Ankle joint set at 10° of dorsiflexion

– Anterior rigid tibial band (patellar tendon strap)

– Offset knee joint with bail lock

– Proximal posterior thigh band

Types of HKAFO• Reciprocal Gait Orthosis (RGO)

• It is used for upper lumbar paralysis in which active hip flexion is preserved.

• RGO consists of bilateral HKAFO with offset knee joints, knee drop locks, posterior plastic AFO, thigh pieces, custom molded pelvic girdle, hip joints, and a thoracic extension with Velcro®

straps, in addition to the control mechanism

Hip orthosis• Purpose:

– To resist femoral adduction.

– Mostly in elderly patients who have had total hip joint replacement.

• Parts:

– Two position lock which permits full extension and 95 degree of hip flexion and adjustable adduction stop.

Trunk – hip – knee – ankle – foot orthoses

• THKAFO

MISCELLANEOUS

• Weight bearing orthoses

• Fracture orthoses

• Angular and deformity orthoses

• Hip orthoses for paediatrics disorders

complications

• Compression phenomenon

• Heat and water retention

• Patient orthoses interfacial affects

Prosthesis

Definition

• Prosthesis is a device or artificial substitute designed to replace, as much as possible , the function or appearance of a missing limb or body part

Aim

• To achieve maximum functional independence with prosthesis

• Not the same as amputee rehabilitation

• Eg wheelchair mobility who are unable to walk

Classification

• Level of amputation

- eg transfemoral , transradial

• Structure

- exoskeleton , endoskeleton

• Function

- cosmetic , functional

ExoskeletalEndoskeletal

Parts

• Socket /interface

• Suspension mechanism

- standard suction

- elastometric

• Struts/tubes(pylons)

• Articulating joints

• Terminal device

-Socket

-Suspension system

-Extension joints (knee assembly)

-Shank/pylon

-Terminal device(usually includes foot and Ankle )

Suction&Mechl close fitting

1. End bearing

– End of the stump bears the weight

2. Total Contact socket

– load is distributed to entire stump

– supports all the distal tissues within the closed system

– As there is total contact proprioception will be good.

– give good sensory feed back.

– good control of stump

– acts as a circulatory pump

– . During stance phase , positive pressure encourages venous return;

– during swing phase ,negative pressure encourages distal blood flow.

Socket WT bearing – 2 types

Total Contact socket– Used for most older patients

– Offers “partial suction”

– Suspended by pelvic belt and hip joint that is attached to socket

– A selsian bandage suspension preferred over pelvic belt as the latter often interferes with sitting

Suction socket prosthesis

• Indicated for amputees for smooth residual limb contours

• Volume fluctuants such as weight gain and fluid retention– contraindications

Disadvantages

• Difficulty in obtaining press fit

• Ocassional lossof suction in sitting position

• No medium for absorbing perspiration

• Requirement of volume and weight stability

suspension system-Soft belts

• Used as primary or auxiliary suspention

• Traditional form is silesian belt– Simple

– disadvantage

• hygiene if it is non removable

•Discomfort due to constrictive effect

• Total elastic suspension (TES)– New ,made ofelasticneoprene lined with smooth Nylon

– Belt fits around proximal 8” of prosthesis

• Hip joint with pelvic band or belt– Provides rotational stability

– significant mediolateral pelvic stability

– Essential when abductors are week

and amputees are obese

Silesian bandage

Hip joint,pelvicband waist belt

• held on by suction and close anatomical fit

• most suitable for above knee.

• eliminates the hip joint and pelvis belt or shoulder harness;

• permits free rotator motion about the hip

• and eliminates piston action of the stump in the socket , permitting greater toe clearance and smoother gait.

• No stump sock needed.

• closely fitted • create negative pressure

during the swing phase• and positive pressure that

expels air through a flap valve during the stance phase.

• The tight fit is applied at the upper two and half or three inches and along the anterior wall of the socket, the reminder stump hangs free.

• A groove in the anteromedial wall accommodates the adductor tendons.

Suction socket prosthesis

1. Axis system2. Friction mechanism3. stabilizers-

• Axis systemSingle axis ….

– Axis of prosthetic knee is same as that of weighty bearing axis

– Flexion easier, But stance phase control difficult

Posterior off set axis…– Axis of prosthetic knee is posterior

– Flexion difficult, stance phase control easier

Polycentric….– variable center of rotation –advantage in both

phases

• Friction mechanism

Constant friction– Hinge to dampen knee swing

– Allows single speed walking

– Most used in children

– Not used for older or weaker

Variable friction-cadence control– Staggerd friction pads

– More friction at extreme ranges,

– Less friction at mid swing

– Allows walkig at more speed ,but not durale

Medium friction Oil (hydraulic) friction

Air (pneumatic)friction

Allows best gait pattern –best for active patients-expensive

Medium friction

(hydraulic) friction

Constant friction

“ Intelligent prosthesis (IP)”

Programmed to each individual user during walking to achieve the smoothest, most energy-saving pattern.

Reacts to speed changes

Intelligence does not extend to understanding environmental considerations

Ex. stairs, ramps or uneven terrain.

•utilizes electronic sensors•detect rate and range of shank

•Provides instant friction adjustments to changes in gait pattern

‘C-LEG’

Friction mechanism

• Stabilizers

Manual locking knee

left locked in extension,

unlocked whole sitting to permit flexion

Used in weak ,unstable patients primarily

StabilizersManual locking

1. Endoskeleton

“Modular prosthesis”

2,Exo skeleton:

Endoskeleton:“centrally located tubular

structure • made of prefabricated.

Made of carbon fibers• the load bearing structure• The socket used over it• Adjustments can be easily

made • These are called “Modular

prosthesis”

• Exo skeleton:-conventional artificial limbs outer visible “skin” like -Inner hollow structures.-made of aluminum ,plastic -adjustments are difficult

-accurate measurement should be there in the beginning it self.

ExoskeletalEndoskeletal

• Providing contact between to the ground the foot provides shock absorption and stability during stance

• influences gait biomechanics by its shape and stiffness. This is because the trajectory of the centre of pressure (COP) and the angle of the ground reaction forces is determined by the shape and stiffness of the foot and needs to match the subjects build in order to produce a

normal gait pattern.

• The main problem found in current feet is durability, endurance ranging from 16–32 months [

• These results are for adults and will probably be worse for children due to higher activity levels and scale effects.

articulated

Non articulated

Non articulatedArticulated

Non articulated

Ex:1)sach Foot(solid Ankle cushion Heal)

2)Madras foot-modified sach

–Post TA like look-sponge between heel&ground

3)Jaipur foot

4) dynamic -new

-spring in keel-energy stored and released

Articulated

SINGLE AXIS

MULTI AXIS

• Designed in 1958 by Eberhart and Radcliffe

• One of the most widely prescribed foot is the solid-ankle-cushion-heel (SACH) foot, due to its simplicity, low cost, and durability and light weight.

• It has a cushioned heel that compresses during heel strike,simulating plantar flexion, and a rigid anterior keel to roll over during the stance phase.

• It is prescribed for juvenile and geriatric amputees but may be inappropriate for active community ambulators and sports participants.

SACH foot

SACH Foot(solid Ankle cushion Heal)

Some movementt in all directionsUseful when not used for heavy dutyWomen/childrenNot suitable for indian amputies

barefoot/squating cannot

SACH foot

Jaipur foot • Mcr&vulcanised rubber• Looks natural• Bare foot

walking/squatingpossible/crossleg/rough use

• 3level movmt• Inv/eversion possible –

hence can walk on uneven area

• Cheap-durable-water resistant

• Madras foot is mainly used in the southern part of India

• It is composed of :-• Wooden keel • Canvas rubber • Hard rubber • Soft rubber • Swade lather.

Has the Advantage of bare foot walking, durability and cultural modifications like toe rings etc.

Single axis ankle and wood foot• Heavy duty activities, rapid plantar flexion at heal

strike

Multi axis

Trans tibial prosthesis

Patellar tendon bearing prosthesis

Trans-femoral prosthesis

Spot the difference..

Disarticulation prosthesis

Complications

• Dermatological problems

• Phantom sensation

• Phantom pain

• Choke syndrome

• Increase in energy consumption

Bionic arm

Thank You