Innova&onsinFractureRepair

May12,2016

Adam Strom, DVM, MS, DACVS-SA

Outline

1.   Pathophysiologyoffracturehealing2.   Biomechanicsofplate/screws3.   Historyoflockingplate4.   Minimallyinvasiveplate

osteosynthesis(MIPO)5.   Currentuses/research6.   Thefuture

Fracturehealing:Inthepast…

• AnatomicReduc&onandRigidFixa&on– Extensivesurgicaltrauma

• Disturbanceoffracturehematoma(FH)• Devasculariza&onofbonefragments• TraumatosurroundingsoV&ssues

– Interfragmentarystrain– Riskofnonunionorimplantfailure

Fracturehealing

• Goals– Encouragehealing– Stabilizefracture– Minimizepain– Returnappearance

• Length• Rota&on/axialalignment• Jointsurfacealignment

– Earlyreturntofunc&on!!!

Fracturehealing

• Primarybonehealing(directorendosteal)– Rigidfixa&on– Strain<2%– Minimalcallus– Skips&ssuedifferen&a&on– RepairviaHaversianosteones

Primaryhealing

• Contacthealing– <0.01mm– Strain<2%

• Gaphealing– Gap<1mm– Strain<2%

Secondaryhealing

• Secondarybonehealing(indirectorendochondral)– Lessstableenvironments– Stepwisechangein&ssue

• Eachstepdecreasesstrain

Strain

• Changeinlength/Originallength(ΔL/L)– ie:5µmgapwith0.2µmdisplacement=4%strain(0.2/5)

•  Increasedstrainpreventscertain&ssuesfromforming.

Straincont.

• Strainreduc&on– Increasedgaplength(comminu&on,reduc&on,resorp&on)

• ie:7µmgapwith0.2µmdisplacement=2.8%strain(0.2/7)

– Decreaseddisplacement• ie:5µmgapwith0.1µmdisplacement=2%strain(0.1/5)

Straincont.

• Strainvariesbetweensimilarsimpleandcomminutedfractures

Internalfixa&on

•  Openanatomicreduc&onwithinternalfixa&on(ORIF)– Primarybonehealing– Mayrequirewideexposure– Ar&cularreconstruc&on– Pre-contouringofplate

•  Biologicinternalfixa&on– SupportfromtheboneandsoV

&ssues&llpresent– Minimallyinvasiveorclosed

reduc&on– Minimiza&onofimplants

Biologicfixa&oncont.

• Openbutdonottouch(OBDNT)

• Minimallyinvasivepercutaneousosteosynthsis(MIPO)

Platebiomechanics

• Platefunc&ons1.  Compression2.  Neutraliza&on3.  Buhress4.  +/-Bridging

Platebiomechanicscont.

• DynamicCompressionPlates(DCP)– Eccentricholes–axialcompression

– Compressionofplatetoboneviascrew

– Nega&ves• Lossofrigidreduc&ond/tplatecontour

• Periostealcompression

Platebiomechanicscont.

• LimitedContact-DCP(LC-DCP)– Reducedcontactwithperiosteum

– Decreasedweaknessatscrewholes

Platebiomechanicscont.

• Lockingplates– Fixedanglescrews– Screwslockedintoplate– Internalfixator

• ShorterdistancethanESF–increasedrigidity

• Nopintracts– Nointerfragmentarycompression

Biomechanicscont.

•  Indica&ons– Diaphysealfractures– Comminutedfractures– Osteopenicbone– Riskofinfec&on

• Contraindica&ons– Simplefractures– Intraar&cular

• Cost

Biomechanicscont.

• Screwposi&on

• ScrewNumbers

• Screwdepth

• Drillguideandtorquelimit

History

• PointContact-Fixa&on(PC-FIX)

• LessInvasiveStabiliza&onSystem(LISS)

• LockingCompressionPlate(LCP)

LockingCompressionPlate(LCP)

• LCPprinciples– Compression

– Bridging– Combina&on

LockingCompressionPlate(LCP)

• Combina&onhole– 200°captureoflockinghead.

– Lockingpor&onissmallestpor&onofhole

Screws

•  Types– Cor&cal,cancellous– Selftapping– Selfdrillinglocking

•  Lockingscrewspull-out– Widercore,smallerthreads– Monocor&calpurchase

LCPscrewplacement

• Rela&onshipbetweenangleofscrewinser&onandstabilityofplate

• Screwsinsertedatdifferentangles(0,5,10°)

• Testedun&lfailure• Significantstabilitydecreaseat>10º

LCP

• Currentlyavailableinsizes1.5,2.0,2.4,2.7,3.5mmandup

• Canbeusedondogsaslihleas1kg

LCP

LCP

LCP

AdvancedLockingPlateSystem(ALPS)

• Titaniumplates• Lockingandstandardscrews• Minimalplatefootprint• Bendingin3planes

• Needforbiomechanicalliterature

TheFuture

• Specificplates– PHILOS

• Tibial– TOMO-Fit

• Shoulder

• Computerguidedsurgery

…andpresent:Biologicalosteosynthesis

•  PreservesoV&ssue&vascularintegrity•  Remotemanipula&onofmainfragments•  Restorelength&3-Dbonealignment

Alignment

…andpresent:Biologicalosteosynthesis

• BonegraVsnotnecessary• Limitedhardware

vs.

Biologicosteosynthesis

• Results:– Increasedcallusproduc&on– Acceleratedradiographicunion– Earliergaininbiomechanicalstrength– Earlierreturntofunc&on

KinastC,BolhofnerBR,MastJW,andGanzR.Subtrochantericfracturesofthefemur.Resultsoftreatmentwiththe95degreescondylarblade-plate.CORR1989Jan;(238):122-30.HeitemeyerU,KemperF,HierholzerG,etal(1987)Severelycomminutedfemoralfractures:treatmentbybridging-plateosteosynthesis.

ArchOrthopTraumaSurg;106(5):327–330.JohnsonAL,SmithCW,SchaefferDJ.Fragmentreconstruc&onandboneplatefixa&onversusbridgingplatefixa&onfortrea&nghighlycomminuted

femoralfracturesindogs:35cases(1987–1997).JAmVetMedAssoc;213(8):1157–1161,1998.RozbruchSR,MiillerU,Gau&erE,etal.TheEvolu&onofFemoralShaVPla&ngTechniqueCORR1998;354(195-208)

GrundnesOetal.,ActaOrthopScand,1993,64,3,340-342

MIPO

•  Tibialfracturesin10animals(6K9and4Fel.)– Pre-surgicalplanning– Medialproximalanddistal

incisons,tunneling– 2-4screwsateachend

•  MeanSX&me59min•  Nosecondprocedures•  Goodtoexcellentoutcome

inall

• Indirectbiologicalapproaches:• OBDNT(OpenButDoNotTouch)• MIO(MinimallyInvasiveOsteosynthesis)

BiologicalOsteosynthesis

MIP(P)O(MinimallyInvasive(Percutaneous)PlateOsteosynthesis)

• GroupI:Anatomicalreduc&on(n=39)• GroupII:Bridging-plateosteosynthesis(n=32)

HeitemeyerU,KemperF,HierholzerG,etal(1987)Severelycomminutedfemoralfractures:treatmentbybridging-plateosteosynthesis.ArchOrthopTraumaSurg;106(5):327–330.

Bridging-plateosteosynthesisfor71comminutedfemoralshaVfractures

Conven&onal(n=24) Biological(n=23)Clinicalunion(mos) 5.4 4.2Delayedornonunion 16.6% 0%

Infec&on 20.8% 0%BonegraV 10 0

Conven&onalvs.Biologicalpla&ng:47subtrochantericfracturesofthefemur

KinastC,BolhofnerBR,MastJW,andGanzR.Subtrochantericfracturesofthefemur.Resultsoftreatmentwiththe95degreescondylarblade-plate.CORR1989Jan;(238):122-30.

• ORIF(n=22)• ESF(n=25)• Nodifferencesin:

– Hospitaliza&on– Timetounion

• Complica&ons:– ORIF18%– ESF4%

• Conclusion:– Closedreduc&on>Openreduc&on

DudleyM,JohnsonAL,OlmsteadM,etal.Openreduc&onandboneplatestabiliza&on,comparedwithclosedreduc&onandexternalfixa&on,fortreatmentofcomminuted&bialfractures:47cases(1980–1995)indogs.JAmVetMedAssoc;211(8):1008–1012,1997

ORIFvs.closedreduc&onwithESF47&bialfracturesindogs

– GroupI:Anatomicreconstruc&on(n=20)– GroupII:Bridgingplatefixa&on(n=15)– Nodifferencesin

• Hospitaliza&on• Alignment• Complica&ons

– Bridging-platefixa&on:• Shorteropera&ve&mes• Faster&mestoradiographicunion

JohnsonAL,SmithCW,SchaefferDJ.Fragmentreconstruc&onandboneplatefixa&onversusbridgingplatefixa&onfortrea&nghighlycomminutedfemoralfracturesindogs:35cases(1987–1997).JAmVetMedAssoc;213(8):1157–1161,1998.

Anatomicreduc&on/platefixa&onvs.bridging-platefixa&onin35femoralfracturesindogs.

• Alignmentrestoredandsimilartocontralateral&biae

Prospec&veEvalua&onofMIPOin36TibialFracturesin28Dogsand8Cats

GuiotLP,DéjardinLM.Prospec&veEvalua&onofMinimallyInvasivePlateOsteosynthesisin36Nonar&cularTibialFracturesinDogsandCats.VetSurg40(2011)171–182.

• Meanhealing&me36/45days

GuiotLP,DéjardinLM.Prospec&veEvalua&onofMinimallyInvasivePlateOsteosynthesisin36Nonar&cularTibialFracturesinDogsandCats.VetSurg40(2011)171–182.

Prospec&veEvalua&onofMIPOin36TibialFracturesinDogsandCats

• Minorcomplica&ons(11%)• Majorcomplica&on(3%)

GuiotLP,DéjardinLM.Prospec&veEvalua&onofMinimallyInvasivePlateOsteosynthesisin36Nonar&cularTibialFracturesinDogsandCats.VetSurg40(2011)171–182.

Prospec&veEvalua&onofMIPOin36TibialFracturesinDogsandCats

MIPO–clinicaloutcome

•  Tibialfractures(36)

•  Healing&me– ORIF87d.*– MIO36to45d.#

•  Complica&ons– ORIF18%(severe)*– MIO2.8%(severe)#– MIO8.5%(minor)#

*Dudley,JAVMA 1997#MSU36consecu&vecases

677616

6 w

eeks

MIPO

MIPO

MIPO

MIPO

MIPO–clinicaloutcome

• Humeralfractures(10)

• Healing&me– ORIF68*to140d.^– MIO38d.#

• Complica&ons– ORIFupto38%– MIO0%#

*Kirkby,JAAHA2008;^Moses,AusVetJ2002#MSU10consecu&vecases

694109

4 w

eeks

MIPO• Techniqueapplicabletoalllongbones

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