Silicone in prosthetics – Properties and Use

Freygarður Þorsteinsson

February 22, 2016 Reykjavik University

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Agenda

• About Össur

• About Silicones

• Use of Silicones in prosthetics

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About Össur

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Employees: ~ 2,500

Sales: ~ > $ 500m

Global leader in non-invasive orthopaedics

Second largest player in bracing and supports

and prosthetics worldwide

Growing through innovation and expanding in the

value chain

Listed on Nasdaq OMX Copenhagen

ÖSSUR TODAY – WHO WE ARE

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OUR STRATEGY

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0%

10%

20%

30%

40%

50%

0

100

200

300

400

500

600

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Sales EBITDA % margin

GROWTH STORY

$ m

illio

n

Prosthetics

consolidationGrowth

Prosthetics

integration and

restructuring

B&S

consolidation

B&S integration and

restructuring

CAGR: 25%

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Bra

cin

g &

su

pp

ort

sP

rosth

etics

Injury

Solutions

People living with

osteoarthritis

People recovering from

fractures, ligament injuries or

need a post operative treatment

GLOBAL PROVIDER OF HEALTHCARE SOLUTIONS

USER PROFILE IMPROVING PEOPLE‘S MOBILITY

Non surgical treatment by unloading

affected joint with braces

Products stabilizing joints

Complete product offering for

lower extremity prosthetics

Advanced microprocessor

controlled feet and knees

People living with lower

extremity amputation

OA

Mechanical

products

Bionic

products

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Bra

cin

g &

su

pp

ort

sP

rosth

etics

# 3 globally

MARKET DYNAMICS

58%

42%

# 2 globally

• Aging population

• Prevalence of Osteoarthritis

• Demand for quality of life

• Reimbursement

• Aging population

• Technological developments

• Vascular diseases & diabetes

• Reimbursement

ÖSSUR MARKETS & TRENDS

SALES1 MARKET

• Market size: $ 950m

• Expected market growth: 3%

• Market size: $ 2,700m

• Expected market growth: 3-4%

1 Based on total sales split in 2014

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GLOBAL OPERATIONS – WELL DIVERSIFIED

Headquarters

Reykjavik, Iceland

Össur Asia

Shanghai,China

Össur Americas

California, USA

Össur EMEA

Eindhoven,

Netherlands

Operations in 18 countries - 2,500 employees

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ÖSSUR WORLDWIDE IP PORTFOLIOSTATUS Q3 2015

• Registered patents: 1095 • Pending applications: 397

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Silicone as biomaterial

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Fact

Most of you have been in contact with silicone in some form today

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History of silicone

•Before 1930: Silicone atom compounds with Si-C bonds created

and investigated

•1930-40: Silicone commercialized

•1940’s-present: Silicone bio-inertness and properties investigated

•1950’s: Silicone first used in medical applications

•1980’s: Silicone liners first produced by Össur

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Characteristics of silicones

• Non-reactive

• Thermally stable/ Non-combustible

• Electrically insulating

• Optical clarity

• High permeability to gases

• Radiation resistant

• High purity

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Properties of silicone elastomers

• High elongation (typically 600 - 1000%)

• Good tear strength

• Unique modulus at typical elongation

• Controllable softness

• Low compression set

• Oxygen permeability

• Bio-inert

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Typical uses of silicone

• Semiconductors (electronics)

• Automotive (gaskets and seals)

• Aerospace (seals)

• Implants

• Other medical grade products

• Additives in various cosmetic products

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The Conversion

From sand to… silicone liner

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Preparation of silicone

SiO2 + 2C → Si + 2COQuartz coke

Si + 2CH3Cl → Me2SiCl2 + other

2Me2SiCl2 + H2O → 2Me2Si(OH)2 + HCl

Unstable

Electric

Furnace

Reactor

3000 °C

Cu catalyst300 °C

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Preparation of silicone - cont.

HO[(CH3)2SiO]MH →

Linear siloxane

KOH

Octamethylcyclotetrasiloxane, D4

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Preparation of silicone - cont.

D4 + Endblockers → Linear polymer

Linear polymer + various additives → Silicones with different properties

Base or

Acid

catalyst

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The silicone family tree

Fluids

(Free chains)

Gels

(Crosslinked)

Elastomers

(Crosslinked and

reinforced)

Resins

(Heavily

crosslinked)

Silicone

Personal care

products

Soft tissue

implants

Wound and

burn treatment

Catheters

Prosthetic

products

Intraocular

lenses

Pressure

sensitive

adhesives

Reinforcement

for optically

clear silicone

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The silicone family tree

Fluids

(Free chains)

Gels

(Crosslinked)

Elastomers

(Crosslinked and

reinforced)

Resins

(Heavily

crosslinked)

Silicone

Personal care

products

Soft tissue

implants

Wound and

burn treatment

Catheters

Prosthetic

products

Intraocular

lenses

Pressure

sensitive

adhesives

Reinforcement

for optically

clear silicone

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Grades of silicone elastomers

• Medical grade – Unrestricted

- Suitable for long term implants (>28 days)

• Medical grade – Restricted

- Suitable for implants up to 28 days

• Engineering grade

- Same material as the medical grade but less testing on each batch, listed on FDA master list.

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Silicone - Use in

prosthetics

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The task

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The prosthesis

Liner

Socket

Foot

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Clinical Need

TechnicalSolution

Suspension

Comfort

Fit

Skin care

Elongation

Compression set

Durability

Biocompatibility

Matching needs and solutions

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Tensile Strength

• According to ASTM D412-06a

• To measure tensile properties of various silicones, namely Force @ 100%

elongation [N/mm²], Force @ 200 % elongation [N/mm²], Strain @ Peak [%] ,

and Stress @ Break [N/mm²]

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Physical properties - Modulus

Stress-strain curve

-20

0

20

40

60

80

100

120

140

160

180

Elongation (%)

Lo

ad

(N

)

100 200 300-100 400 500 600

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Tear Strength Measurements

• According to ASTM D2240

• Tear strength is defined as the maximum force per mm² required to tear

silicone which already has a nick in it

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Durometer

• According to ASTM D 2240 -05

• To compare the indentation hardness in silicone elastomers

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Photo: Íþróttasamband fatlaðra

The users

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Silicone elastomer, Iceross

Stiffness modified by chain length, level of crosslinking & skincare

additives

SkinCare ingredients

=+

Dimethylsiloxane-chains

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Össur main silicone types

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Exposure

• We estimate that everyday Össur silicone liners cover 50 – 60000 m2 of human flesh

• That is about the size of 7-8 average size football fields

• Use time per day can be 12-16 hours

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Why silicone?

• Stability and Comfort

- Good elastic properties reliable suspension- Conforms to residual limb shape total contact

• Biocompatibility

- Long history in medical use very low risk of medical problems due to the material

- Stable material very low allergy risk

• Durability

- Smooth surface easy to clean and maintain- Good mechanical properties durable liners

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The future

• More specialized solutions meeting individual needs (custom made solutions)

• Active ingredients – special functions

• Combination of materials