A-CLASS®

Highly Cross-Linked Polyethylene

• Highlycross-linkedpolyethylenereferstoUHMWPEexposedtoradiationdosesinexcessof4MRad1(A-CLASS®Poly=7.5MRad)

• Increasingcross-linking=increasingwearresistance+decreasingmechanicalproperties

• Balanced processing of A-CLASS® polyethylene drastically reduces wear while maintaining good mechanical properties

A-CLASS® Highly Cross-Linked Poly vs. Conventional Poly

• Wearinducedosteolysishasbeenrecognizedasanimportantclinicalissuewithconventionalpoly2

• Highlycross-linkedpolyethylenewasintroducedinthemid1990’stoimprovethebearingwearcharacteristicsofTHAandallowforlargerheads

• Wright testing shows a 92% or greater wear reduction for A-CLASS® polyethylene vs Wright conventional polyethylene3

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Cross-Linking Process• Wright’sA-CLASS®PolyisIrradiatedwith7.5MRads

• Higherradiationdose=morecross-linking,slightlybetterwearresistance,andweakermechanicalproperties

• Wrighthasfoundanoptimumbalanceofenhancedwearpropertieswhilemaintainingimportantmechanicalpropertiesofthematerial

Product X-Link Dose1

A-CLASS®(Wright) 7.5MRad

Marathon®(DePuy) 5MRad

Longevity®(Zimmer) 10MRad

Crossfire®(Stryker) 10.5MRad

Durasul®(Zimmer) 9.5MRad

X3®(Stryker) 9MRad

E1®(Biomet) 10MRad

Heat Treatment• Wrighthasdevelopedaproprietarythermalremeltingcyclethatremovesfreeradicals

• Remeltinghasbeenshowntoeliminatemorefreeradicalsthanbelow-meltprocedures5

• Thisprocesshasbeenshowntoimprovetheoxidativestabilityofthematerial6

- Validatedinnaturalagingstudy:Nodetectableoxidationafterweartestingto5Mcandaginginairfor3years!

- Validatedinacceleratedagingstudy:Nodetectableoxidation!

• Wright remelting cycle eliminates need for anti-oxidant doping (i.e. Vitamin E)

Product HeatTreatment1

A-CLASS®(Wright) Remelted

Marathon®(DePuy) Remelted

Longevity®(Zimmer) Remelted

Crossfire®(Stryker) BelowMelt

Durasul®(Zimmer) Remelted

X3®(Stryker) BelowMelt

E1®(Biomet) BelowMelt*

Final Sterilization• Allpolyethylenelinersrequirepost-processingsterilization

• Mostcommonsterilizationmethods

-Ethyleneoxide(EtO)

•Doesn’taddfreeradicals7

-Gasplasma

•Doesn’taddfreeradicals8

-Gammaradiation

•Adds free radicals9

• Sterilizationwithoutradiationenhancesshortandlong-termoxidativeresistanceinsimulatorstudy10andinshelfagingstudy11

Product Final Sterilization1

A-CLASS®(Wright) ETO

Marathon®(DePuy) GasPlasma

Longevity®(Zimmer) GasPlasma

Crossfire®(Stryker) 3MRadgamma-N2

Durasul®(Zimmer) ETO

X3®(Stryker) GasPlasma

E1®(Biomet) Gamma

Poly Material Selection• WrightusescompressionmoldedGUR1020UHMWPE

• GUR1020hasahigherimpactstrength,tensilestrength,andyieldstrengththanGUR10504

Product Material1

A-CLASS®(Wright) GUR1020

Marathon®(DePuy) GUR1050

Longevity®(Zimmer) GUR1050

Crossfire®(Stryker) GUR1050

Durasul®(Zimmer) GUR1050

X3®(Stryker) GUR1020

E1®(Biomet) GUR1050

*Heated during diffusion of Vitamin E.

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WrightMedicalTechnology,Inc.5677AirlineRoadArlington,TNUSA38002901.867.9971800.238.7117www.wmt.com

Wright Medical EMEAHoogoorddreef51101BAAmsterdamTheNetherlands011.31.20.545.0100www.wmt-emea.com

References1. StephenKurtz,PhD,UHMWPEBiomaterialsHandbook,SecondEdition:UltraHighMolecularWeightPolyethyleneinTotalJointReplacementand

MedicalDevices(SanDiego:ElsevierAcademicPress,2009),p55.

2. BonoJV,SanfordL,ToussaintJT.Severepolyethylenewearintotalhiparthroplasty.ObservationsfromretrievedAMLPLUShipimplantswithanACSpolyethyleneliner.J Arthroplasty.Apr1994;9(2):119-125.

3. DataonfileatWright.

4. “StandardSpecificationforUltra-High-MolecularWeightPolyethylenePowderandFabricatedFormforSurgicalImplants”.ASTMInternational,2007.F648-07.

5. StephenKurtz,PhD,TheUHMWPEHandbook:Ultra-HighMolecularWeightPolyethyleneinTotalJointReplacement(SanDiego:ElsevierAcademicPress,2004),p112.

6. DataonfileatWright.

7. StephenKurtz,PhD,TheUHMWPEHandbook:Ultra-HighMolecularWeightPolyethyleneinTotalJointReplacement(SanDiego:ElsevierAcademicPress,2004),p45.

8. StephenKurtz,PhD,TheUHMWPEHandbook:Ultra-HighMolecularWeightPolyethyleneinTotalJointReplacement(SanDiego:ElsevierAcademicPress,2004),p46.

9. StephenKurtz,PhD,TheUHMWPEHandbook:Ultra-HighMolecularWeightPolyethyleneinTotalJointReplacement(SanDiego:ElsevierAcademicPress,2004),p44.

10. McKellopH,ShenFW,LuB,CampbellP,SaloveyR.Effectofsterilizationmethodandothermodificationsonthewearresistanceofacetabularcupsmadeofultra-highmolecularweightpolyethylene.Ahip-simulatorstudy.J Bone Joint Surg Am.Dec2000;82-A(12):1708-1725.

11. WillieBM,AshrafiS,AlajbegovicS,BurnettT,BloebaumRD.Quantifyingtheeffectofresintypeandsterilizationmethodonthedegradationofultrahighmolecularweightpolyethyleneafter4yearsofreal-timeshelfaging.J Biomed Mater Res A.Jun12004;69(3):477-489.