Prosthetics and Orthotics Manufacturing Guidelines - 1 ... · PDF filealignment Jig For lower-limb Prosthetics Physical Rehabilitation Programme Manufacturing guidelines 0868/002 09/2006

alignment Jig For lower-limb ProstheticsPhysical Rehabilitation Programme

Manufacturing guidelines

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9/20

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MISSION

The International Committee of the Red Cross (ICRC) is an impartial, neutral and independent organization whose exclusively humanitarian mission is to protect the lives and dignity of victims of war and internal violence and to provide them with assistance. It directs and coordinates the international relief activities conducted by the Movement in situations of conflict. It also endeavours to prevent suffering by promoting and strengthening humanitarian law and universal humanitarian principles. Established in 1863, the ICRC is at the origin of the International Red Cross and Red Crescent Movement.

Acknowledgements:

Jean François GallayLeo GasserPierre GauthierFrank JoumierJacques LepetitBernard MatagneJoel NiningerGuy NuryPeter PoestmaHmayak Tarakhchyan

and all prosthetists-orthotists who have worked in ICRC-assisted physical rehabilitation centres.

International Committee of the Red Cross19 Avenue de la Paix1202 Geneva, SwitzerlandT + 41 22 734 60 01 F + 41 22 733 20 57E-mail: icrc.gva@icrc.orgwww.icrc.org© ICRC, September 2006All photographs: ICRC/PRP

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Table of contents

Foreword 2Introduction 41.Useofthealignmentjig 5

1.1Descriptionofthejig 51.2Possiblemovementsforpositioningthepositiveinspace 6

2.Installationofthejig 83.Choiceandlocationofcentringaccessories 94.Someexamplesofuse 11

4.1Trans-tibialsockets 114.2Trans-femoralsockets 13

Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

� ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

Foreword

The ICRC polypropylene technology

Sinceitsinceptionin1979,theICRC’sPhysicalRehabilitationProgrammehaspromotedtheuseoftechnologythatisappropriatetothespecificcontextsinwhichtheorganizationoperates,i.e.,countriesaffectedbywarandlow-incomeordevelopingcountries.

Thetechnologymustalsobetailoredtomeettheneedsofthephysicallydisabledinthecountriesconcerned.

Thetechnologyadoptedmustthereforebe:

• durable,comfortable,easyforpatientstouseandmaintain;• easyfortechnicianstolearn,useandrepair;• standardizedbutcompatiblewiththeclimateindifferentregionsoftheworld;• low-costbutmodernandconsistentwithinternationallyacceptedstandards;• easilyavailable.

Thechoiceoftechnologyisofgreatimportanceforpromotingsustainablephysicalrehabilitationservices.

Forallthesereasons,theICRCpreferredtodevelopitsowntechniqueinsteadofbuyingready-madeorthopaediccomponents,whicharegenerallytooexpensiveandunsuitedtothecontextsinwhichtheorganizationworks.ThecostofthematerialsusedinICRCprostheticandorthoticdevicesislowerthanthatofthematerialsusedinappliancesassembledfromcommercialready-madecomponents.

WhentheICRClauncheditsphysicalrehabilitationprogrammesbackin1979,locallyavailablematerialssuchaswood,leatherandmetalwereused,andorthopaediccomponentsweremanufacturedlocally.Intheearly1990stheICRCstartedtheprocessofstandardizingthetechniquesusedinitsvariousprojectsaroundtheworld,forthesakeofharmonizationbetweentheprojects,butmoreimportantlytoimprovethequalityofservicestopatients.

Polypropylene(PP)wasintroducedintoICRCprojectsin1988forthemanufactureofprostheticsockets.Thefirstpolypropyleneknee-jointwasproducedinCambodiain1991;othercomponentssuchasvariousalignmentsystemswerefirstdevelopedinColombiaandgraduallyimproved.Inparallel,adurablefoot,madeinitiallyofpolypropyleneandEthylVinylAcetate(EVA),andnowofpolypropyleneandpolyurethane,replacedthetraditionalwooden/rubberfoot.

In1998,aftercarefulconsideration,itwasdecidedtoscaledownlocalcomponentproductioninordertofocusonpatientcareandtrainingofpersonnelatcountrylevel.

�ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

Objective of the manuals

TheICRC’s“ManufacturingGuidelines”aredesignedtoprovidetheinformationnecessaryforproductionofhigh-qualityassistivedevices.

Themainaimsoftheseinformativemanualsareasfollows:

• TopromoteandenhancestandardizationofICRCpolypropylenetechnology;• Toprovidesupportfortrainingintheuseofthistechnology;• Topromotegoodpractice.

Thisisanotherstepforwardintheefforttoensurethatpatientshaveaccesstohigh-qualityservices.

ICRCAssistanceDivision/HealthUnitPhysicalRehabilitationProgramme

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Introduction

Everymanufacturingtechniquehasitsownspecificrequirements.ThetechniquebasedontheuseofpolypropylenewhichhasbeendevelopedbytheICRC’sphysicalrehabilitationprogrammeisalsosubjecttothisrule;itmustcombinequality,easeofuseandlowcost.

Thecomponentsfortrans-tibial(TT)andtrans-femoral(TF)prosthesesproducedbyCREquipementsSA(CRE)allowforcertainangularandtranslationadjustments,butthesepossibilitiesarelimited:• 20mmintranslationorsliding(2x10mmeachsidefromtheneutralpoint)• 20degreesintilting(2x10°oneachsideofthemedianaxis).

Itisadvisabletoretaintheseadjustmentpossibilitiesfordynamicalignment,andtotakeintoaccountthefactthatstaticalignmentfollowstheweight-bearingreferencelinestoachieveaneutralposition.

Inmostofthetechniquesusedforsocketmanufacturewithpolypropylene,theconnectioncomponent,calledthecup,isincludedinthesocketduringthethermoformingphase.Itisthelinkthatholdstheotherpartsoftheprosthesistogether.UsingthistechniquemeansthatthealignmentmustbeadjustedBEFOREthesocketthermoformingprocess.

Anothertechniqueallowstheproductionof“full-contact”sockets.Faultypositioningoftheconnectingcomponent(thesocketcup)duringweldingmakesalignmentdifficultorimpossibletoachieve.

Particularattentionmustthereforebepaidtowhethertheconnectingcuporsocketcupisplacedonthepositivebeforeorafterthethermoformingphase.

AspecialtoolhasbeendesignedandmanufacturedbytheICRCandCREtohelpprostheticandorthotic(P&O)technicianscompletethesealignmentphaseseasilyandwiththerequiredprecision.

Thistoolisthealignmentjig.

Objective of this document

Thepurposeofthisdocumentistodemonstratetherelevanceandusefulnessofthealignmentjigforobtaininghigh-qualityresults.

ThealignmentprinciplesappliedarebasedoninternationalP&Ostandards.

Remark

ThisdocumentisnotatechnicalmanualonthemanufactureofTTandTFprostheses.

ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

�ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

1.1 Description of the jig

Thealignmentjigisastainlesssteelframeabout2metreshighand0.8metreswide.Itissturdyandstable.

Use OF The alIgnmenT jIg 1

Positioning phase Fixation phase

6Thepurposeofthejigistofacilitatethepositioninginspaceofthepositiveplaster,andtoholdtheconnectioncup(orsocketcup)firmlyandpreciselyduringtheoperationtofixittotherectifiedpositivewithplaster(orbywelding).

Obviously,thisfixationphaseisindependentofthetypeofsocketused:theillustrationshowsTTprostheseswithandwithoutsoftsocket.

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4Inthecentreofthejigtherearetwocomponentswhichallowthepositioninginspaceandimmobilizationoftheplasterpositiveinrelationtothepositionoftheconnectioncup.

Atthetop:theballandsocketjoint.Thisallows:• suspensionandimmobilizationofthe

positive;• rotationaroundthepipeaxis;• forward,backwardandlateral

movements.

Below:thetray.Thisimmobilizestheconnectingpart(cuporsocketcup).

Theheightofthetrayisadjustable.Itisfixedonaverticalaxis,whichrepresentsthelegpartofthefutureprosthesis.

Tohelpthetechnicianvisualizethecomponentpartsofthefutureprosthesis,aprostheticfootisfixedtothelowerendofthisaxis.

Thealignmentprinciplesareindependentofheight.

ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

1.2 Possible movements for positioning the positive in space

4Longitudinalmovements.

4Lateralmovements.

4Ballandsocketrotation.

�ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

4Lockingoflongitudinalmovements.

4Gradientofthepipe.Thepipecandescribeaconeofabout30°atthesummit(about15°aroundtheverticalline).

4Theballandsocketallowscorrectpositioningofthepositiveevenwhenthepipeiswronglyplaced.

4Ballandsocketdetailsandblockingscrew.

Lockingofrotationandgradientofthepipecarrier.

Lockingoflateralmovements.

Tighteningofthepipe.

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Twoprecautionsmustbetakenbeforestartingtousethejig:

• Checkwithaspiritlevelthatthecentralbeamsupportingtheverticalaxis(whichinturnsupportsthetray)isperfectlyhorizontal,andmakeanynecessaryadjustmentsbymeansoftheadjustablefeet.

• Installplumblinesbeyondtherangeofmovementsofthepipecarrier.

Byestablishingfrontalandsagittalplanes,theseplumblinesallowexactapplicationoftheprinciplesofalignment.

InsTallaTIOn OF The jIg 2

4Frontalandsagittalplanesareestablishedwithplumblines(4x)beyondthemovementsofthepipecarrier.

4Checkwithaspiritlevelthatthecentralbeamisperfectlyhorizontal;adjustbymeansofadjustablefeet.

ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

�ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

(A)The tray

ChOICe anD lOCaTIOn OF CenTRIng aCCessORIes 3

4Thetrayhas3holesØM8.

Theholesituated2cmfromthecentreisusedforadultTFalignment

ThecentralholeisusedforadultandchildTT.

Theholesituated1cmfromthecentreisusedforchildTF.

WhenusedforadultTF,thepositivesagittalplanisperpendiculartothecentralbeam,andwhenusedforchildTF,themainlineofthisbeamisthesameasthepositivesagittalplane.

Positive front for adult size

Positive front for child-size BK

(B)Production by means of the “cup” (use of the centring cylinder)

Positive front

Positive rear

6AdultandchildTTalignment. 6AdultTFalignment.

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Positive front

Positive rear

6TFchild-sizealignment. 6Theconnectingcuponthetray.

(C)Production by means of the socket cup

Thesocketcupmakesitpossibletomanufacture“full-contactsockets”(withcontactontheentiresurfaceofthestump,includingtheextremity).

Theprinciplesarethesame;onlytheaccessoryisdifferent.

6TheaccessoryforcentringthesocketcupispositionedforTTinthecentralhole.

6ThesocketcupispositionedforadultTF.

5Centralbeammainline.

ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

��ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

sOme examPles OF Use 4

sockets without terminal contact

Theconnectioncupisassembledwiththepositivebeforethesocketthermoformingoperation(methodmostfrequentlyused).

�.� TT sockets

(A) alignment of a short TT positive (right)

6Posteriorview:Thepictureistakenofthepositivewithoutsoftsockettomaketheshapesandmarksofthepositivemoreclearlyvisible.Thepresenceorabsenceofasoftsockethasnoeffectonthealignmentprinciples.

View before joining View after joining

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6Lateralview:

View before joining View after joining

(B) alignment of a long TT positive (left)

lateral view before joining Posterior view before joining

ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

��ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

�.� TF sockets

(A) Parameters to be observed between the CRe knee and the alignment jig

a=22mm(minimum)

b=40mm

Dimensionstobedetermined:

a deviceforadjustingalignment

b distancebetweenupperpartofthekneeandkneeaxis

a b

6Thereisa2cmgapbetweenthesocketfixationscrewandthekneeaxistotaketheflexumintoaccount.

6Thekneeaxisisonthesameverticallineasthepipe(thepartbelowtheknee).

Thesamepositioningfeaturesarefoundonthealignmentjig.

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(B) long stumps

6Itispossibletoadjustthedistancefromischiumtokneewhentheconnectioncupisbeingfixedbycalculatingheightainadvanceaccordingtothedetailsgivenabove.

Posterior view before joining side view after joining

a

ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

��ICRC Physical Rehabi l i tat ion Programme Manufac tur ing Guidel ines Al ignment J ig for Lower-Limb Prosthet ics

(C) short stumps

“Full-contact” sockets

Theconnectingelement(thesocketcupinthiscase)isassembledwiththesocketafterthethermoformingoperation.

Warning:Specialcaremustbetakenwhenthesocketcupisusedastheconnectingcomponentwiththe“contactsocket”,forthesafetyofthepatient.Indeed,inordertostrengthentheweldingbetweensocketandcupafterthermoforming,thesocketmustbecarefullyadjustedasshownintheillustrationabove.

Then,toensurethepatient’ssafety:• theweldingshouldbeperformedwithparticularcare;• thepatientshouldnotbeleftaloneduringthefittingandrehabilitationphases;• polypropylenemustbeusedforfinishingsoastoforman“exoskeleton”thatguaranteesthe

solidityoftheprosthesis.

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Thesocketcupiseasytouse:• Alignthesocketaccordingtothepossibilitiesofferedbythejig.• Installinthetraythecentringdevicedesignedforsocketcups.• Cutthesocketcupatthedesiredlengthandgiveittheappropriateshape.• Weldthesocketcuptothesocketlightlywithaweldingiron.• Removetheassemblythusobtained.• Endwithcarefulwelding.

(A) TT socket

short TT socket (side view) long TT socket (posterior view)

short TF socket (posterior view) long TF socket (side view)

(B) TF socket

ICRC Physical Rehabi l i tat ion Programme

MISSION

The International Committee of the Red Cross (ICRC) is an impartial, neutral and independent organization whose exclusively humanitarian mission is to protect the lives and dignity of victims of war and internal violence and to provide them with assistance. It directs and coordinates the international relief activities conducted by the Movement in situations of conflict. It also endeavours to prevent suffering by promoting and strengthening humanitarian law and universal humanitarian principles. Established in 1863, the ICRC is at the origin of the International Red Cross and Red Crescent Movement.

Acknowledgements:

Jean François GallayLeo GasserPierre GauthierFrank JoumierJacques LepetitBernard MatagneJoel NiningerGuy NuryPeter PoetsmaHmayak Tarakhchyan

and all prosthetists-orthotists who have worked in ICRC-assisted physical rehabilitation centres.

International Committee of the Red Cross19 Avenue de la Paix1202 Geneva, SwitzerlandT + 41 22 734 60 01 F + 41 22 733 20 57E-mail: icrc.gva@icrc.orgwww.icrc.org© ICRC, September 2006All photographs: ICRC/PRP

Physical Rehabilitation Programmeankle-Foot orthosis

Manufacturing guidelines

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