3d printing in orthopedics

3d printing in orthopedics, Three-dimensional printing

1. 3D PRINTING IN ORTHOPEDICS
Can ThoCentral General Hospital
Center for Trauma and Orthopedics
Bs.Lê CôngDanh

2. Introduction
•Withtheincreasingcomplexityofoperationsandsurgicaldecision-
making,three-dimensional(3D)printingisanovelmodalitywiththe
potentialtomakeahugeimpactinthesurgicalfield.
•In1984,thefirstpatentfora3DprinterwasfilledintheUnitedStatesby
CharlesHalltitled,“Apparatusforproductionof3Dobjectsby
stereolithography”,whichwas,ineffect,theworld’sfirst3Dprinter
•Thefirstreporteduseinorthopaedicswasin1999asanaidto
preoperativeplanningincomplexspinalsurgery

3. Introduction
In orthopaedics, the use of 3D printing can be broadly split into three categories.
Pre-operative planning
Inpre-operativeplanning,3Dprintedmodelscanallowsurgeonstovisualiserelevant
anatomyandhelpaidexecutingcomplexoperations.
3D implants, prostheses, splints, and external fixators; surgical
instrumentation and guide
3Dprintedimplantscanbeusedfordirectreplacementofalargedefectaftertumour
resectionandtoaidreconstructioninlimb-salvagesurgery.
3D patient-specific instrumentation (PSI)
PSIscanhaveawideapplicationacrossorthopaedicsandcanbelargelyusedformore
accurateimplantplacement

4. •Whilstinitially3Dproductswereusedforcomplexcases,theyarenow
becomingpartoftheroutine,andthisislikelytohaveasignificantimpacton
allofourpracticesintheupcomingyears,astheyhavebeenseentooffer
severaladditionaladvantages
•Apreoperativeexaminationofthe3Dmodelallowsthesurgeontopredict
intraoperativedifficulties,toselecttheoptimalsurgicalapproach,toplanin
advancethecorrectimplantplacement,toidentifythescrewtrajectoryand
theneedforspecialequipment.
Introduction

5. 3D printing: How does it work?
•3Dprintingconvertsacomputer-generated3Dimageintoaphysicalmodel.
•3Dmodelcreationisbasedon3DDICOM(digitalimagingandcommunicationsinmedicine)
formatdataderivedfromCTorMRI.
•Itneedstobeconvertedintoafileformatwhichcanberecognizedbythe3Dprinter.TheDICOM
fileisthereforeuploadedintoaprogram(e.g.,MimicsfromMaterializeforWindows,Osirix(free-
opensource)forMac)whichenables3Dreconstructionoftheimage.
•Itisthenexportedinafileformat(stereolithography[STL])makingitreadablebysoftware
(computeraideddesign-CAD)whichisusedtodesign3Dobjects.DefectsorerrorsintheSTLfile
arecorrectedbeforeexportingtothe3Dprinter.
•3Dprinters“additivelymanufacture”orcreateobjectslayerbylayer

6. Guarinoetalreportedtreatmentof10patientswith
pediatricscoliosisand3complexpelvicfracturepatients
andconcludedthat3-Dprintingimprovedtheplacement
accuracyofpedicleandpelvicscrews,andtherefore
decreasedtheriskofiatrogenicneurovasculartrauma.
2007
Brownetal.reportedthat3-Dprintinghelpedinsurgicalplanningandin
reducingtheexposureofradiationduring117complexsurgicalcases.
2003
Kacletal.foundthatrapidprototypingmightbe
usefulforteachingandsurgicalplanning.
1997
3Dprintinghasbeenincreasinglyusedbyseveral
authorsinthefieldoforthopaedictraumaforthe
last2decades.

7. Applications of 3D printing in specific
anatomical areas of orthopaedic trauma

8. Wedevelopedanewtechniqueusingathree-dimensional(3D)modelandadistalclavicle
reconstructionplatetotreatosacromialeandacromionfractures.First,a3Dmodeloftheacromion
wasprinted,thenanosteosynthesisplatewaspre-benttofittheexactshapeandcurveofthe
acromion.Wetestedthistechniqueandpresentreportsonfivepatients,threewithosacromiales
andtwowithacromialfractures.Wefollowedthesepatientsduringtheirrehabilitationandevaluated
themusingtheConstant-MurleyandtheDisabilitiesoftheArm,ShoulderandHandscores.

10. Wedescribeanoveltechniqueusingareal-sizethreedimensionally(3D)-printedclaviclemodel
asapreoperativeandintraoperativetoolforminimallyinvasiveplatingofdisplacedcomminuted
midshaftclaviclefractures.
Acomputedtomography(CT)scanistakenofbothclaviclesinpatientswithaunilateral
displacedcomminutedmidshaftclaviclefracture.Bothclaviclesare3Dprintedintoareal-size
claviclemodel.

12. Youetalin2016treated66oldpatientsaged61–76yearswithcomplicatedproximalhumeralfractures,whowere
randomlyassignedtotwogroups(34patientsinthetestgroupand32patientsinthecontrolgroup).Inthetestgroup,3D
printingwasusedtobuildthe3Dfracturemodel,usingdataacquiredfromthin-sliceCTscanandprocessedbyMimics
software.Ithelpedinconfirmationofdiagnosis,designingindividualsurgicalplan,simulatingoperativeproceduresand
performingtheoperationasplanned.
Inthecontrolgroup,onlythin-sliceCTscanwasappliedforpreoperativeplanning.
Surgeryduration,bloodloss,fluoroscopyusageandtimetounionwerecompared.Screwlengthsplannedbeforethe
surgeryandactuallymeasuredduringthesurgerywerealsocompared.

14. BetweenFebruary2009andOctober2015,131patientswith3and4-partproximal
humeralfracturesweredividedinto3groupsonthebasisofthepreoperativeplanning
method:conventional(n=53),virtualsurgical(n=46),and3Dprinting(n=32).

16. WeretrospectivelyidentifiedproximalthirdhumeralshaftfracturestreatedbetweenFebruary2012andFebruary2015.The
patientsweredividedintotwogroupsaccordingtothetreatmentprocedure:aSynbonegroupanda3D-printedgroup.
IntheSynbonegroup,longproximalhumeralinternallockingsystemplateswerepre-contouredintohelicalshapeon
Synbonesbeforesurgery,whileinthe3D-printedgroup,theywerecontouredon3D-printedbonemodels.
Durationofsurgeries,bloodlossvolumes,theincidenceofcomplications,andthetimetofractureunionwererecorded,
andfunctionaloutcomeswereassessedbytheConstant-Murleyshoulderscoreand.theMayoElbowPerformanceScore
(MEPS)at1-yearfollow-up

18. Kimetal:Thirteenpatientswithdistalintercondylarhumeralfractureswere
randomizedtoundergosurgeryusingeitherconventionalplates(n = 7)or
3D-printedplates(n = 6)atourinstitutionfromMarchtoOctober2014.Both
groupswerecomparedintermsofoperativetimeandelbowfunctionat6
monthfollow-up

20. Zhengetal.BetweenJanuary2006andMay2008,12maleand6femalepatientswithcubitusvarusdeformities
underwentscanningwithspiralcomputedtomography(CT)preoperatively.Themeanagewas15.7years,
rangingfrom13to19years.Three-dimensionalCTimagedataoftheaffectedandcontralateralnormalbonesof
cubitusweretransferredtoacomputerworkstation.Three-dimensionalmodelsofcubituswerereconstructedby
useofMIMICSsoftware.The3DmodelswerethenprocessedbyImagewaresoftware.Anosteotomytemplate
thatbestfittedtheangleandrangeofosteotomywas"reversely"builtfromthe3Dmodel.Thesetemplateswere
manufacturedbyarapidprototypingmachine.Theosteotomytemplatesguidetheosteotomyofcubitus.

22. Thirtyconsecutivepatients(twenty-threemalesandsevenfemales)withacubitusvarus
deformityresultingfromthemalunionofadistalhumeralsupracondylarfracturewere
includedinthisstudy.BetweenOctober2003andMay2011,thepatientsunderwenta
three-dimensionalcorrectiveosteotomywithuseofacustom-madesurgicaltemplate.The
patientswerethenfollowedforaminimumoftwelvemonths.Weevaluatedradiographic
parameters,includingthehumerus-elbow-wristangleandtiltingangle,aswellasthe
rangesofmotionoftheelbowandshoulderatthetimeofthemostrecentfollow-up.

24. •Yangetalin2017.Fortypatientswithelbowfractureswererandomlydividedintoa
3Dprinting-assistedsurgerygroup(n=20)andaconventionalsurgerygroup(n=20).
•Surgeryduration,intra-operativebloodloss,anatomicreductionrate,incidenceof
complicationsandelbowfunctionscorewerecomparedbetweenthetwogroups.The
independent-samplest-testwasusedtocomparethedatabetweengroups.

26. •Intotal,48patientswithAOtypeCfracturesofthedistalradiuswereenrolledinthestudybetweenJanuary2014andJanuary
2015.
•Theyweredividedrandomlyinto3Dmodel(n=23)androutinetreatment(n=25)groups.A3Ddigitalmodelofeachdistal
radiusfractureintheformergroupwasconstructed.Themodelwasexportedtoa3Dprinterforconstructionofafullsolid
model.
•Duringeachoperation,theoperativetime,amountofbloodloss,andfrequencyofintraoperativefluoroscopywererecorded,
whichwereregardedasprimaryoutcomemeasures.PatientswerefollowedtoevaluatesurgicaloutcomesbyGartland-Werley
scores,radiologicalevaluation,andrangeofmotionofwrist,andthesewereregardedasthesecondaryoutcomemeasures.

28. •BetweenDecember2013andOctober2015,thethumbsoffivepatientswithgrade3thumbdefects
werereconstructedusingawrap-aroundflapandsecondtoetransplantaidedby3Dprinting
technology.CTscansofhandsandfeetwereanalyzedusingBoholosurgicalsimulatorsoftware
(www.boholo.com).
•Thisallowedforthecreationofamirrorimageofthehealthythumbusingtheuninjuredthumb.Using
3Dimagesofthereconstructedthumb,amodelofthebigtoeandthesecondtoewascreatedto
understandthedimensionsofthedonorsite.Thismodelwasalsousedtorepairthedonorsitedefect
bydesigningappropriateiliacboneandsuperficialcircumflexiliacarteryflaps.

31. •Prospectiverandomizedcasecontrolstudywasconducted.21patientswereincluded.10
patientsweredistributedin"case"groupandremaining11in"control"group.
•Incasegroup,patient-specificreal3Dmodeloffracturedacetabulumwasgeneratedusing
rapidprototypingtechnologyandplateswerecontouredpre-operatively.Controlgroupwas
treatedusingintra-operativecontouredplates.Boththegroupswerecomparedusing
parameters:Bloodloss,Surgerytime,post-operativereductiononX-ray,post-surgical
residualdisplacementandreductionachievedasevaluatedbyCTscan.

33. Onehundredthirty-sevenpatientswithunstablepelvicfracturesfrom2014to2016were
retrospectivelyanalyzed.Basedontheusageof3Dprintingtechnologyforpreoperative
simulationsurgery,theywereassignedto3Dprintinggroup(n=65)andcontrolgroup
(n=72),respectively.Thesetwogroupswereassessedintermsofoperativetime,
intraoperativefluoroscopy,postoperativereductioneffect,fracturehealingtime,and
follow-upfunction.

35. →Nghiên cứu hồi cứu này đã chứng minh công nghệ in 3D là một phương
pháp tiếp cận tiềm năng để cải thiện chẩn đoán và điều trị gãy xương chậu.

36. First,16driedhumancadavericpelviseswereusedtoconfirmthe
anatomicalaccuracyofthe3Dmodelsprintedbasedonradiographicdata.
Next,nineclinicalcasesbetweenJanuary2009andApril2013wereusedto
evaluatethesurgicalreconstructionbasedonthe3Dprintedmodels.The
pelvicinjurieswerealltypeC,andtheaveragetimefrominjuryto
reconstructionwas11weeks(range:8-17weeks).

39. Atotalof38patientswithunstablepelvicfractureswereanalyzedretrospectivelyfromAugust2012to
February2014.Allcasesweretreatedoperativelywithinternalfixationassistedbythree-dimensionalprinting
fromminimalinvasivepara-rectusabdominisapproach.BothpreoperativeCTandthree-dimensional
reconstructionwereperformed.Pelvicmodelwascreatedby3Dprinting.Dataincludingthebestentrypoints,
platepositionanddirectionandlengthofscrewwereobtainedfromsimulatedoperationbasedon3Dprinting
pelvicmodel.MattaandMajeedscorewereusedtoevaluatecurrativeeffectsafteroperation.

41. Thirty-threeconsecutivepatients(33knees)wereoperatedonusingthesameMedialclosing-wedge
distalfemoralosteotomy(MCWDFO).3D-printedcuttingguidesandlockingguideswereusedtolocate
theosteotomycutplaneandtofacilitateclosingthewedgein12patients(3D-guidegroup).Another21
patients(conventionalgroup)underwentMCWDFOfollowingtheconventionaltechnique.Thedesired
correctionwasdefinedasaweight-bearingline(WBL)coordinate50%ofthewidthofthetibialplateau
fromthemedialtibialmargin.ThedeviationbetweentheplannedandexecutedWBLcoordinate,
surgicaltimeandfluoroscopictimewerecompared

45. Weprospectivelyfollowedup40consecutiveadultpatientswithclosedTPFwho
underwentsurgicaltreatmentofreconstructionofthetibialplateauwiththeuseof
minimallyinvasivefixation.Sixteenpatients(group1)wereoperatedusingapre-
operativeandintra-operativerealsize3D-model,while24patients(group2)were
operatedwithout3D-modelprinting,butusingonlypre-operativeandintra-
operative3DTc-scanimages

50. Chungetal.used3Dprintingtocreatemodelsofcalcanealfractures
andintactipsilateralcalcaneumbymirrorimagingfromtheopposite
side.Theyalsomadepreshapedcalcanealplatesandutilizedthesefor
percutaneousfixationofcalcanealfractures

53. A35-year-oldmalewasadmittedtothehospitalwithhighfallinjury.Physicalexaminationrevealed
obviousexternalrotationanddeformity(shortening)oftheleftlowerextremity,withtendernessand
longitudinalthrobbingpainaswellasbonesqueakingandrubbing.Subcutaneousecchymosiswas
visibleonthelateralsideofthegreatertrochanterandbuttock.Thepatienthadmultiplefractures
includingaleftacetabulardoublecolumnfracturewithquadrilateralbodydisplacementtothe
medialside(AOclassification:C1.3),combinedwithleftiliacwingandrightpubicfractures
avulsionfractureoftheposteriorcruciateligament(PCL)

58. Miscellaneous topics
•Atypicalfemoralfracture
•Validityof‘Mirroring’
•Externalfixation
•3DPrintedboneclips
•Woundcare
•Scaffoldingforboneandcartilage
•Bracing
•Prosthesis

59. Discussion
•Thecurrentliteratureconsistentlyshowedthat3Dmodelcohortshadshortersurgerytimes,lower
volumesofbloodlossintraoperativelyandshorterfluoroscopytimes.Theabilitytousethemodels
tosimulatethesurgeryallowedforplannedplacementofimplantsandselectionofinstrumentation,
thusreducingthenumberofadjustmentsandtheneedtocontourimplantsintraoperatively.Models
werealsousedtoevaluatethestructuralintegrityoflandmarkstowhichtheimplantsarefixated.
•Patientssurveyedintheliteraturerespondedwithenthusiasmregardingtheuseof3Dprinted
models.Allpatientsfeltthattheybetterunderstoodtheirinjuryandtheirupcomingsurgery.
Surgeonsalsofeltthat3Dprintedmodelswereavaluablecommunicationtoolwhencounselling
patients.Theyfelthavingatangiblestructuretoshowthepatienttheproceduretheywereaboutto
performwassuperiortoallcurrentlyavailablemedia.

60. Discussion
•These3Dmodelshavealsoshowntobeusefulinstudents’andresidents’
education,makingthemabletoperformsimulatedsurgery,andhavingalsoan
effectonpatient’ssafety,especiallywithinexperiencedsurgeons,insteadof
performingriskyproceduresdirectlyonthepatient.
•Theuseof3Dprintedmodelsmayresultinimprovedqualityofpreoperative
planningfornovicesurgeonsandbeusefulforimprovingskilloutsidetheoperating
room.