A prosthesis is a device designed to replace a missing part of the body or to make a part of the body to work better. Diseased or missing eyes, arms, hands, legs or joint are commonly replaced by artificial or Assistive device.

 

Types of prosthesis

Artificial limb is graded depending on;
(I) Level of amputation
(ii) Specific use.

There are of 4 types

1} Trans-radial-Below elbow (B.E or TR)
2} Trans-Femeral-Above elbow (AE or TF).
*3} *Trans tibial -Below knee(BK or TT).
4 }Trans humeral -Above knee(AK or TH)

Classification For Upper extremity can be further done into.

  • Passive/cosmetic/Aesthetic devices.
  •  Body powered device
  •  Externally powered (myoelectric) device.

Commonly replaced body parts include;

a)Lower legs and feet.
b)The leg with the knee.
c)Arm’s above and below the Elbow.
d)Hands.

PART OF THE PROSTHESIS

SOCKET -Plastic receptacle to which the residual limb is contained
APPENDAGES -Are the distal parts of an extremity like hands and foot.
JOINTS -Can be of wrist, Elbow, Shoulder, Ankle, Knee ,hip.)
SHANK – Connection module that connect the appendages and joint to the socket.

 

SOCKET

This is the plastic receptacle in which the residual limb is contained.

Their fabrication is based on different types of material ie Thermoset plastic and thermoform plastic.; Thermoset material include resin and hardener which can be molded on the positive limb on a negative plaster cast. Thermosets material has special property of hardening when you subject it to heat source and different from thermoform plastic which become soft when subjected to a heat source.
Therefore thermoform plastic techy uses Polypropylene thermoplastic or polyurethane plastic to contain a residual limb.

Socket can be secured in place by assistance use of other technologies like Silicone liners with shuttle lock adaptors, just to add on Integrated vacuum adapters, Vacuuming valve, selesian leather belt design, cuff suspension.

 

APPENDAGES

Hands and foot forms part of appendanges

Hands
✓cosmetic/aesthetic why hands
✓Body powered hand
-Thump movement
-2-finger movement.
-3finger movement
-all fingers movement.
✓Externally powered Manus movement, from 1,2,3,to all finger movement using diodes implanted on existing body muscles.

 

FOOT

The human foot are specifically designed to perform functions and qualitatively tested to perform that activity for specified period of time.

So activities level are graded into.

K1, K2,K3,K4 to Hydraulic foot types.

Country of Origin also contribute to quality assurance..

Example

K1-SACH foot, single axis foot with toes.
NB; Foot keel can be either soft wood, with MCR to provide functional parts of the foot.

K2-SACH foot with Plastic keel or hard wood keel , Dynamic foot Multiple axis feet.

K3- Low ankle carbon feet; Triton, Trione, gressinger plus Dynamic motion trias, meridium as of German origin ,low ankle carbon foots

K4 – High ankle carbon foots. Examples C-walk, Action, Taleo, Taleo harmony, Taleo low profile, Triton Empower.

NB Special features of K3 are
✓Controlled planter flexion of 12⁰
✓Multi-axial movements to compress insecurities
Basic damping at heel-strike
✓Psychological controlled rollover

K5 or Final are the patented foots with Hydraulics controlled functions..

Some foot can be graded to k2-k3 or k3-k4 this denate special features that utilized on its durability within the activity levels

JOINTS

(I)Mechanical knee
(ii) Externally controlled joint movement from: Pneumatic or hydraulic depending on medium of control
(III) Micro-Processors knee.

Mechanical Knee
-Single axis knee joints
-Multi axial knee joints

(IV)Externally aided
-Pneumatic…… Uses springs , specially designed metal to compress air to control extension and flexion of the knee.
-Hydraulic-uses Oil to control flexion and extension of knee joints.

(V) Microprocessors

Uses battery to control flexion and extension of knee joints.

COSTING & PRICING FACTOR OF PROSTHESIS .

(I) Technology – post operative treatment.
(ii) Material
(III) Government policies
(IV) Donation modules
(V) Company Dynamic

TECHNOLOGY
✓Appropriate
✓Standard

The above two are basics which are offered by government institutions to; a} Specified treatment for a secondary condition of a patient like secondary fracture, Oedematous residual limb and gait training for 1st users

Cost vary from 30,000ksh to 500,000KSH depending on the type of foot, suspension method and material used.
✓Higher tech
350,000-750,000KSH
✓Advance tech
450,000ksh-1.5ksh
✓Sports# cyclic
# Jogging
# Running
# extreme sports

800,000ksh-3.5 mil KSH.

MATERIAL .

The most commonly world acceptable material in fabrication process for prosthetics components are as below

APPENDAGES -Polyutherine, MCR plastics ,Forms. Silicone.

SHANK- Wood, Aluminum, Iron, Stainless steel, Titeniot Compressed oir or air

SOCKET
thermoplastic; copolymer, monopolymer, polyurethelyne plastic, soft and rubber-sized thermoforms.

Thermoset plastic of liquid hardener or powder hardener

_SUSPENSION OF SOCKETS._

Leather;Goat skin,pure leather.
Polyester webbing, Cotton webbing

JOINTS

Wood, Aluminum, Iron, Stainless steel, Titenium, Titenium alloys.

 

GOVERNMENT POLICIES

Government review on tax policies affect costing ; Government can also check price caps by establishing industries where these components, material used in Prosthetics factories end product are manufactured.

NB Fabrication of prosthesis involves assembly of existing parts as well as making of customized residual limb.

Material consumable used on customization of limb products contribute to overall cost of the prosthesis.

DONATION MODULES

Non government institutions which offer rehabilitation services mostly Assistive devices usually do get used prosthetics components. These components are eventually donated to PWD which can also Lower the overall cost

Other government institutions also receive components, donations and subsidized human resource remunerations which eventually lower the overall cost of prosthesis.

COMPANY DYNAMICS

A private company dealing with prosthesis (Artificial limb)can also be involved is a price skimming, research grants which can lower overall prices of an artificial limb.

As a part of Giving back to the community, a company may decide to offer prosthesis as a subsidized price not to mention Other well wishers or even government which can donate in a form through the company.

COSTING therefore is more constant when material, components, human resources or grants has been factored in it’s productions.

Since the government has not extensively been involved in Assistive Production , manufacturing their issuances cost and price will always vary with these factors.

Orthopedic technologists in Kenya aims at using scientific knowledge for smooth transfer of weight from the body to the ground by obeying universal principle of transfers but will also form part of rehabilitation programmes by ensuring suitable community Rehabilitation programmes. Other Cadres which are involved in prosthesis/artificial limb issuance is prosthetist and orthotists .