Surgical Technique

• Jack Farr, MD CartilageRestorationCenterofIndiana Indianapolis,Indiana

• Brian Cole, MD RushCartilageRestorationCenter Chicago,Illinois

Slot InstrumentsFor Meniscal Transplantation

Introduction

Meniscustransplantationisanaccepted

treatmentoptionforpatientsexperiencing

symptomssecondarytotheabsenceof

oneorbothmenisci.1-5Basicscience

providesevidencefortheimportanceof

maintainingthebonyinsertionsitesof

theanteriorandposteriorhorns.These

studiessuggestthatsofttissuefixation

aloneissub-optimalforrestorationof

thetibiofemoralloadsharingfunction

ofthemeniscus.8-10Thus,depending

uponsurgeonpreference,themeniscus

allograftsarepreparedsothattechniques

utilizingabonebridgeorboneplugscan

beperformed.Thissurgicaltechnique

describesabonebridgetechniqueused

inconjunctionwiththeStrykerSlot

Instrumentsformeniscaltransplantation.

TheSlotInstrumentsaredesignedto

improvetheefficiency,reproducibility,

andqualityofallograftmeniscus

transplantationforeithermedialorlateral

allografttransplantation.Itmaintains

therelationshipoftheanteriorand

posteriormeniscalhornsandeliminates

theneedfortransosseoustunnels,which

complicatetheprocedure.

Note 1. Indications

Meniscustransplantationperformed

inkneeswithtibiofemoralarthrosisof

GradeIIIorIVisassociatedwithless

favorableresultsinanimalstudies.12

Whenindicated,concomitantcartilage

restorationproceduresshouldbeperformed

atthetimeofmeniscustransplantation

(i.e.,osteochondralgrafting,autologous

chondrocyteimplantation).

Similarly,significantlimbmalalignment

andligamentinsufficiencyshouldbe

correctedeitherpriortoorconcomitant

withmeniscustransplantation.13,14Attention

tothelocationofosteotomycutsor

ligamenttunnelsiscriticaltodeterminethe

appropriatepositionoftheslotpreparedin

thetibiatoreceivethemeniscusboneblock

(seeSection3forrecommendationsonthe

orderofmultipleprocedures).

Note 2. Meniscus Sizing

Meniscusallograftsaresideand

compartmentspecific.Pre-operatively,

precisemeasurementsmustbeobtained

fromA/PandLateralradiographswith

magnificationmarkersplacedontheskin

attheleveloftheproximaltibia,toobtaina

correctlysizedallograft.Ifperi-operatively,

inthejudgmentofthesurgeon,thegraft

isseverelyunderorover-sized,orifthe

surgeonispresentedwiththeincorrect

meniscusaltogether(i.e.amedialmeniscus

ratherthanalateralmeniscusorleftvs.

rightmeniscus),themeniscusshouldnot

beused.Smallsizemis-matchesarehandled

withonlyminormodificationsandare

likelytohaveminimaleffectsonanatomic

restoration.Thetechniquesformanaging

sizemis-matcharebeyondthescopeofthis

standardsurgicaltechnique.

Surgical Preparation

1. Position

Dependinguponsurgeonpreference,

thelimbmaybeplacedinastandardleg

holderormaintainedintheunsupported

supineposition.Theposteromedial

and/orposterolateralcornersofthe

jointmustbefreelyaccessibletopermit

unencumberedinside-outmeniscus

suturingtechniques.

2. Exposure

Arthroscopic:Exceptforthesteps

requiredtocreatethetibialboneslot

andtoinsertthemeniscus,itiscommon

formeniscustransplantationtobe

performedarthroscopicallythrough

standardarthroscopicportals.Itis

necessary,however,tocreateamini

arthrotomyinlinewiththeanterior

andposteriorhornsoftheinvolved

meniscustopermitaccurate“in-line”

guideplacementduringslotformation

andforintroductionofthemeniscus.

Dependinguponsurgeonpreference,the

mini-arthrotomymaybeimmediately

adjacenttothepatellartendonor

throughasplitmadewithinthepatellar

tendon.

Open: An ipsilateral parapatel lar

arthrotomy allows adequate exposure

for allograft meniscus transplantation

when performed open or during the

performance of concomitant cartilage

restorationprocedures.

When full exposure of both condyles is

necessary, it may be easier to perform a

tibial tubercle osteotomy with proximal

reflectionoftheextensormechanism.

3. Concomitant Procedures

High Tibial Osteotomy:Usually,

themeniscustransplanttechniqueis

completedfirstincludingthebone

andsofttissuefixationsincethiscan

involvehighforcesto“openthejoint.”

Ifthesurgeondesirestoperformthe

osteotomyfirst,rigidosteotomyfixation

isrequiredtotoleratethemeniscus

repairtechnique,andextremecaution

mustbeusedtoavoidfracturingthrough

theslotintotheosteotomysite.

ACL Reconstruction:First,

arthroscopicallyperformallsoft-tissue

portionsofthemeniscustransplant

technique.ACLtibialandfemoraltunnel

reamingisperformedpriortomeniscus

slotplacement.PlacingthetibialACL

tunnelasclosetothemid-lineaspossible

withoutcompromisingtheanatomical

positionoftheligamentwilldecrease

interferencebetweenthetunneland

amedialmeniscusslot.Themeniscus

bonebridgeistrimmedatthesiteof

intersectionwiththeACLtunnel.This

facilitatesACLgraftpassage.Depending

uponsurgeonpreference,consideration

forhamstringACLgraftreconstruction

mayalsofacilitategraftpassage.When

usingapatellartendongraft,thebone

bridgeofthemeniscalallograftis

temporarilyelevatedtoallowpassage

oftheboneandisthenreducedasthe

tendonportionoccupiesamuchsmaller

volumeofthetunnelcomparedtothe

boneblock.

Fig. 1

Distal Realignment:Allstepsofthe

meniscustransplantareperformedfirst,

followedbythetibialtubercleosteotomy

andotherrequiredsofttissueprocedures

asdeterminedbythesurgeon(i.e.,lateral

release,medialpatellofemoralligament

reconstruction).Performingthetibial

tubercleosteotomyasdistalaspossible

willpreventinadvertentencroachment

onthemeniscusslot.

Autologous Chondrocyte Implantation

or Osteochondral Grafting:Itis

typicallyeasierandsaferforthechondral

proceduretobeperformedafterall

stepsofthemeniscustransplantare

completedtoavoidinadvertentdamage

tothearticularcartilagegraftduring

instrumentationorsutureplacement.

Slot Instruments Surgical Technique

1. Establishing Anatomic Slot Placement

Anatomicplacementoftheslotinline

withthecenterofthenativemeniscus

insertionpointsiscritical.Identify

theremnantanteriorandposterior

attachmentsofthenativemeniscus.

Useanelectrocauteryorelectrothermal

devicetomarkalinethatconnectsthe

centeroftheanteriorandposterior

attachmentsites.

Thehornattachmentsareusuallydiscrete

andreadilyidentifiablestructures.A

notableexceptiontothisistheanterior

hornofthemedialmeniscuswhichhasa

morevariableinsertionnearthe

anterior-mostaspectofthetibialplateau.

Thetrueattachmentsiteisdeeptothe

traversingsofttissueoftheintermeniscal

ligament.

Priortoslotcreation,itiscritical

toidentifyandprotectthecruciate

ligamentsandtheirattachments.

Toallowbettervisualizationofthe

posteriormeniscalhornsandimprove

instrumentplacement,itishelpfulto

performaminimalnotchplastyofthe

ipsilateralfemoralcondyleadjacent

andinferiortotherespectivecruciate

ligamentearlyintheprocedure.

Fig. 2

2. Establishing a Reference Slot

Usingthelineestablishedbetweenthe

meniscusinsertionsitesinStep1,

a4mmun-hoodedburrisusedtocreate

asuperficial(fromanteriortoposterior)

referenceslot.Sincethetibialplateau

typicallycontainsrisesandundulations,

thereferenceslotwillhavevaryingdepths

especiallyatthespineregion,wherethe

depthmaybeactuallydeeperthanthe

averageof4mm.Atapproximately4mm

deepanteriorandposteriortothespine,

thesuperficialreferenceslotallowsthe

depthgauge(4mmindiameter)tosit

flushwiththeadjacentarticularcartilage

oftheplateauandparalleltotheslope

oftheplateauarticularcartilage.

Note:Removeonlythetibialspine

presentalongthislinetofacilitate

creationofastraightanteriorto

posteriorslotintheplaneofthe

tibialslope.Alevelandsmoothslotis

confirmedbyfullyseatingthedepth

gaugeinthereferenceslot.

3. Drill Guide Placement

Placethedepthgaugeinthereference

slotunderdirectvisualizationsothat

thetipisfirmlyengagedagainstthe

posteriorcortexbygentlypullingback

onthedepthgauge.Theetchedlines

onthedepthgaugecanbeusedto

determinethecompleteA/Plengthof

thetibialplateau.

Fig. 3

Fig. 4

Drillthe3.2mmguidepinthroughthe

drillguideholelocatedinferiortothe

depthgaugeholewhilemaintainingthe

drillguidepinparalleltotheslopeofthe

tibialplateau(Fig.6b).Thedrillguide

willprovideahardstopatthedesired

distanceasthedrillchuckcontactsthe

proximalendofthedrillguide.

Maintainthedepthgaugetip

againsttheposteriortibialcortex

andadvancethedrillguideoverthe

depthgaugeuntilthedistalendof

thedrillguideisfirmlyseatedagainst

theanteriortibia.Thedepthgauge

willslideinthedrillguidewhen

thetriggerisdepressed.Releasethe

triggertolockthegaugeinplace.

Thedepthgaugeshouldremainfully

seatedinthereferenceslot.

Placingthedepthgaugeparalleltothe

slopeofthetibialplateaupositions

thefinalslotintheproperanatomic

orientation.Thespikeofthedrill

guidetipwillmaintainpositioning

duringdrilling.

Obtaining Depth

1. Guide Pin and Reaming

FirstverifythetibialA/Pdimension

eitherbythedepthgaugelasermarks

relativetotheproximalmostbracket

ofthedrillguide(A)orthesecond

setoflasermarksmeasuredrelativeto

thedrillguidetip(B)(Fig.6a).Both

markingsshouldreadthesameasthey

pertaintothedistancefromthedistal

tipofthedrillguideasitrestsagainst

theanteriortibiatothehookattheend

ofthedepthgauge.Lasermarksonthe

guidepinallowthesurgeontochuckthe

pintothedesireddistance,asmeasured

fromthedepthgaugelasermark.The

surgeonmaychoosetoreamtoadepth

of3-5mmlessthanthedepthofthetibia

plateau(asmeasuredwithdepthgauge)

topreservetheposteriorcortexofthe

tibia.

A

B

Fig. 5

Fig. 6a

Fig. 6b

Afterguidepinplacement,un-chuck

andremovethedrillguideanddepth

gauge,leavingthedrillpininplace.

Setthedrillcollaronthe8mmdrill

bittothesamedepthasthedrillpin

(3-5mmshortoftheposteriorcortex

ofthetibiaplateau).Tosetthedrill

collar,depressthecirclelasermarks

oneithersideofthecollarandslide

tothedesireddistance.Thegrooves

inthedrillbitallowthesurgeonto

lockthecollarintoplace.Reamover

theguidepintothedesireddistance

(Fig.7aandFig.7b).

2. Slot Preparation

Removethedrillbitandguidepinand

insertthe8mmboxcutterbyplacing

thebulletnoseofthecutterintothe

drilledhole.Gentlyimpactthecutter

withamallettoadvancethecutterinto

thetunneltoremoveresidualbone

aroundthetunnelandbetweenthe

tunnelandthereferenceslot(Fig.8a).

Theboxcuttercreatesaslot8mmin

widthby10mmindepth.Thetines

oftheboxcuttershouldbevisualized

anthroscopicallyastheyareadvanced

throughthearticularsurface.

Usethe7and8mmsizer/raspin

successiontosmooththefinalslot(Fig.

8b).The8mmraspalsoservesasaproxy

fortheallograftboneblockandallows

thesizedbonebridgetoslidesmoothly

intotheslot.Oncethe8mmraspsits

flushwiththetibialplateau,yourslotis

completed.

Insomecases,anarthroscopicburrora

straightrongeurmaybeusedtofurther

debridetheresidualbonefromthe

posteriorsectionofthefinalslot.

Fig. 7a Fig. 7b

Fig. 8a Fig. 8b

3. Meniscal Allograft Bone Bridge Preparation

Dependingonsurgeonpreference,this

techniqueallowsforeitheran8mmbone

blocktopressfitintothe8mmslotor

undersizingthemeniscusbonebridge

widthby1mm(i.e.7mmbonebridge

intoa8mmfinalslot).

Identify Meniscus Attachments:

Dynamicallyidentifybothhornsofthe

meniscusbymovingthemeniscusback

andforthabouttheattachmentsiteslike

abuckethandle(Fig.9a).

Debridetheaccessoryattachments

(includingthe“intermeniscalligament”)

leavingonlythetrueattachments

(usually5-6mminwidth).Unlikethe

otherhornattachments,theanterior

hornofthemedialmeniscususually

extendstotheanterior-mostextentof

thetibialplateauforattachment.Inrare

casesinwhichtheanteriorattachment

is7to9mmwide,leavethebonebridge

beneaththeanteriorhorn7to9mm

wideandtrimtheremainderofthe

bridgetotheplanned7or8mmwidth.

Then,priortoinsertion,enlargethe

anterior-mostaspectoftherecipientslot

withthe7or8mmrasptoacceptthis

widenedarea.

Bone Bridge Width:Useamarking

pentotracethestraightlinesconnecting

theplannedcutsonthemedialand

lateralsideofthebonebridge(Fig.9b).

Cutthebonebridgetoawidthof7mm

or8mm,orasdictatedbythewidthof

thesofttissueattachment(Fig.9C).The

wallsofthegraftsizerworkspaceare

8mmand7mmhigh,respectively.Tofine

tunethemeniscuswidth,thesurgeon

maylaytheboneblockflushagainstthe

wallwiththeheightcorrespondingthe

desiredwidthcut.Thesurgeonmaythen

createthedesiredbonebridgewidthby

“painting”theboneblockwiththesaw

(Fig.9d).(Note:Theboneblockofthe

unpreparedmeniscusallograftisoften

skewtothelineconnectingthehorn

attachments.Donotlettheshapeofthe

unpreparedboneblockinfluenceyour

linesofcutwhendeterminingthefinal

boneblockwidth.)

Fig. 9a

Fig. 9b

Fig. 9c

Fig. 9d

Bone Bridge Height:Cutthebone

bridgetoaheightof10mm.Measure

theheightfromtheattachmentsites,

notfromthetibialspine,whichmay

beseveralmillimetershigherthanthe

horns.Thelasermarkandcuttinggroove

inthegraftsizerworkspaceaidesin

thiscut.Thedistancebetweenthelaser

markandthecuttinggrooveis10mm.

Therefore,positionthemeniscussothat

thelasermarkrunsthroughthehorn

attachmentsitesandthenrunthesaw

throughthecuttinggroovetoattainthe

desired10mmheightcut.(Note:the

“dead”cartilagecoveringthespinearea

ofthebonebridgemayberemoved

toallowbettervisualizationduring

insertionandtohelppreventinadvertent

bonyimpingementontheipsilateral

femoralcondyle.)

Bone Bridge Length: Removeany

bonethatextendsbeyondtheposterior

hornattachment(Fig.11).Bone

extendingbeyondtheanteriorhorn

attachmentisleftintacttoprovide

graftintegrityduringinsertion.This

maybetrimmedfollowingbonebridge

insertion.

Placethebonebridgeinthebone

bridgesizerchannelstoallowitto

slidesmoothlyintothefinalslot(8mm

wideand10mmdeep).Ifalooserfitis

desired,thenusethe7mmchannelto

testthegraftfitinthetibia.Ifapressfit

isdesired,thenusethe8mmchannel.

Fig. 10

Fig. 11

4. Meniscus Insertion

Placeaverticalmattresstractionsuture

using#0PDSthroughthejunctionof

theposteriorandmiddlethirdofthe

meniscus.Usingasinglebarrelcannula,

advancealongnitinolsuturepassingpin

throughaproperlypositionedcannula

fromthecontralateralportalthroughthe

capsuleatthecorrespondingattachment

siteoftheposteriorandmiddlethird

ofthemeniscusandexittheaccessory

posteromedialorposterolateralincision.

Theproximalendofthenitinolpinis

thenwithdrawnfromthecontralateral

portalandintothearthrotomysiteto

helpfacilitatepassageofthemeniscus

intotheknee.Placethetractionsutures

fromthemeniscusthroughtheloopon

theproximalendofthenitinolpinand

withdrawthepinandsuturesfromthe

accessoryincision.Incaseswherethe

sutureisnotanatomicallyplacedwithin

thecapsulerelativetothemeniscus,it

canbesubsequentlyremovedratherthan

usedforfinalmeniscussuturing.

5. Meniscus Insertion and Fixation

Insertthemeniscusthroughthe

arthrotomy,takingcaretoaccurately

alignitwiththerecipientslotwhile

gentlypullingonthetractionsuture.

Theassistantmanuallyopensthejoint

byapplyingavarus(lateralmeniscus)

orvalgus(medialmeniscus)stressto

theknee.Confirmthepropersizeand

positionofthemeniscusbycycling

thekneethroughitsrangeofmotion.

Carefullymatchthemeniscuspositionto

thefemoralcondyleandtibialplateau.

Dependingonsurgeonpreferenceand

thefitofthebonebridgeinthefinalslot,

threechoicesexisttosecurethebone

bridgewithintherecipienttibialslot:

Interference Screw:Ifthebone

bridgefitslooselyintheslotandgreater

fixationisdesired,thenthesurgeonmay

useaStryker7mmby23mmHA/PLLA

screw.Placethescrewcentraltothegraft

(medialsideofthegraftifinsertinga

lateralmeniscus(Fig.12a)).Tappingis

recommended.

Fig. 12a

Bone Pin:Ifthebonebridgefits

moresnugintheslotandadditional

interferencefitisstilldesired,thenthe

surgeonmayusea3.2mmby45mm

allograftcorticalbonepin.Thedrill

guideisalsodesignedtointroducethe

bonepin.

Placetheguideatthejunctionofthe

bonebridgeandthetibialslot,5mm

fromthebaseoftheslotandcentralto

thegraft.Chuckthedrillpintobetween

5mmand10mmanddrillapilothole.

Removethedrillpinwhileleavingthe

drillguideinplace.Insertthebonepin

inthesameholeasusedforthedrillpin

inthedrillguideanddispensethepin

withthetamp(Fig.12b).Insertthepin

onlyasfarasthebackwalloftheslot.

Usearongeurorbonecuttertocutany

portionofthebonepinprotrudingfrom

theslot.

Fig. 12b

Press fit:Ifthesurgeonfeelsasthough

thegraftfitsadequatelyintheslot

withoutadditionalfixation,thenproceed

tomeniscussuturing(Fig.12c).

(Note:Asanotheralternative,

transosseussuturescanbeusedfor

fixationofthebonebridgeintheslot.)

6. Meniscus Suturing

Finally,repairthemeniscuswithvertical

mattresssuturesusinganinside-out

techniqueoraspersurgeonpreference. Fig. 12c

Medial Bone Bridge in Slot Meniscal Allograft Transplantation

Medialmeniscalallografttransplantation(MAT)

ismostcommonlyperformedusingboneplugs

intunnels.Therationaleforthistechniqueis

basedontwofactors:Thefirstisthatplugin

tunneltechniqueistechnicallyfeasiblemedially

ascomparedtothelateralmeniscus.Thatis,the

boneplugintunneltechniquewhenattempted

forlateralMATleadstotunnelconvergence.

Thethinbonewallseparatingthetunnelsoften

wouldcollapsecreatingdifficultywithaccurate

positioningoftheplugswhichisessentialin

propermeniscalhornpositioning.Thus,the

useofabonebridgeforthelateralmeniscus

wasalogicaldevelopmentbasedonthisclose

proximityofthetwohornattachments(Fig.13).

Thesecondfactorinfluencinguseofthe

plug/tunneltechniqueforthemedialMATwas

theconcernforthelossofthemedialtibial

spine/medialfemoralcondyleinteraction/force

transfer.Thissecondtheoreticalfactorisvery

difficulttoevaluatefromapurebiomechanical

standpointbecauseofthetechnicaldifficulties

inmeasuringspine/condyleloadingwiththe

current“forcetransducers”available(e.g.,

Tekscan,Fujifilm).

Fig. 13

Acknowledgingthetheoretical

implicationsoflossofmedialtibial

spine/medialfemoralcondylecontact/

stresstransfer,itisimportanttoreview

thecurrentrecommendedplugintunnel

techniques.Thesetechniquesstressthe

importanceofadequatevisualization

oftheposteriorhornattachmentand

adequateroomtoorientthepluginto

theposteriortunnel.However,anatomy

precludesoptimalvisualizationand

roomforpluginsertioninmostpatients.

Inaddition,asthemedialmeniscus

attachesextra-articullarlyonthe

posteriortibialslopealongandadjacent

tothePCL(posteriorcruciateligament),

toproperlyvisualizethisattachment,

theplugintunneltechniquesuggests

botha“minor”resectionofthemedial

tibialspineanda“minor”posterior

notchplastyofthemedialfemoral

condyle(Fig.14).

Thistechniqueisdesignedtoprovide

theneededvisualizationofthe

posteriorhornattachmentandroom

forplugorientation,butitalsoserves

tobiomechanicallyremoveanyforce

transferbetweenthemedialspineand

themedialfemoralcondyle.Thus,at

thispointinMAT,theredoesnotappear

tobeacompellingevidencetopreclude

theuseofabonebridgeformedialMAT.

Therearepotentialadvantagesofany

bonebridgetechniqueoveraplug

intunneltechnique.First,critical

reviewofsomeplugintunnelMAT

post-operativeradiographswill

revealmanythatviolatetheregionof

theposteriortibialplateautypically

coveredbyarticularcartilage.While

thissmallareaprobablydoesminimal

harmtothetibialplateauarticular

cartilage,itdoesplacetheposterior

hornmedialandanteriortothetrue

anatomicposteriorhornattachment

site.Publishedbiomechanicalstudies

stressthepotentialdeleteriouseffectof

non-anatomicposteriorhornposition.

Second,theanteriorhornattachment

tunnel(forplugintunneltechnique)is

selectedbythesurgeonbasedon“where

theanteriorhornfitswithappropriate

tension”.Itisextremelydifficultfor

asurgeontoselectbothtensionand

position.Thus,mostanteriorhorn

tunnelsareactuallymedialtothe

nativefixationsite.Notonlyhasthis

tunneltechniquerequiredthesurgeon

toselecttheattachmentsites,butany

errorsareadditive(posteriorhornplus

anteriorhorn).Withabonebridge,

additiveerrorsshouldbeavoidedasthe

relationshipsofthehornsisdictatedby

thedonorattachmentsites.Truemedial

meniscalposteriorhornattachment

(extra-articularandadjacenttothe

PCL)isdictatedbytheslotaccepting

thebridge.Finally,theanteriorhorn

attachmentsiteisselectedbythe

anatomyofthedonor(sizematchedto

thepatient),andtheanatomyofthehost

(astheslotisinlinewiththehosthorn

attachments)notthesurgeon.

Thatis,iftheproperlysizedMAThas

beenselected,thenthematchinthejoint

Fig. 14

isnearanatomic.Astheslotmimicsthe

anterior/posterior(A/P)courseofthe

naturalmeniscus,themediallateral

positionofthemeniscalhornsis

anatomicandtheonlyvariable

remainingisthecorrectAPposition

ofthebonebridgeintheslot.The

overallgoalofMATistoduplicatethe

contactareadistributionofthemedial

femoralcondyle(MFC)ontothemedial

tibialplateau.Tooptimizethecontact

area,theMFCmustfullycapturethe

meniscus.Asthe7mmbonebridge

easilymovesinthe8mmslot,cyclingthe

kneenearextension(thereisminimal

A/Pmotionofthemedialmeniscusfrom

0to60degreesofflexion),allowsthe

patient’sanatomy(MFCcapturingthe

MAT)toselectthefinalA/Pposition

oftheMATbonebridgeinslot.Atthat

pointtheMATisfixedinamanner

previouslydescribedforthelateralMAT

technique.Clinicallythistechniquehas

beeninusesince1999withresultsand

complicationssimilartootherreported

techniques.

Fig. 16aOptimal Slot Depth

Optimalbladeplacementallowsasmoothcutofthewallsandroofoftheslotwithoutdamagetothemedialfemoralcondyle.

Aswithmostinstrumentationsystems,theslottechniqueisasurgeonassist,notsurgeonindependenttechnique.Ifthebladesoftheboxcutterarenotoptimal,thenthesurgeonshouldtakeactionsasfollows:

Fig. 16b“Low” Slot

Recognitionthattheblindtunnelistoolowwillprevent“snowplowing”ofthesubchondralbonewithpossibleelevationfractureoftheACLfootprint.Recognitionallowsthesurgeontomanuallypositiontheboxcutterattheappropriatelevel.

Fig. 16c“High” Slot

Thesurgeonshoulddirectlymonitortheprogressoftheboxcutterblades.Iftheyaretoohigh,theycanbedirecteddistallymanuallybythesurgeontopreventinjurytothemedialfemoralcondyle.

Fig. 15

Box Cutter Pearls and Pitfalls

References1. ColeBJ,FoxJA,LeeSJ,FarrJ:Bone

BridgeinSlotTechniqueforMeniscalTransplantation.OpTechSportsMed,11:2,144-155,April2003.

2. StollsteimerGT,SheltonWR,etal.Meniscalallografttransplantation:A1to5yearfollow-upof22patients.Arthroscopy2000;16:343-7.

3. MessnerK.Indicationsformeniscaltransplantation.Whoandhowmanyneedameniscussubstitute?Apersonalview.ScandJMedSciSports1999;9:184.

4. JohnsonDL,BealleD.Meniscalallografttransplantation.ClinSportsMed1999;18:93-108.

5. KuhnJE,WojtysEM.Allograftmeniscustransplantation.ClinSportsMed1996;15:537-6.

6. PollardM.E.,etal.Radiographicsizingformeniscaltransplantation.Arthroscopy1995;11:684-7.

7. ShafferB,etal.Pre-operativesizingofmeniscalallograftsinmeniscustransplantation.AmJSportsMed2000;28:524-33.

8. AlhalkiMM,HullML,HowellSM.Contactmechanicsofthemedialtibialplateauafterimplantationofamedialmeniscalallograft.Ahumancadavericstudy.AmJSportsMed2000;28:370-6.

9. AlhalkiMM,HowellSM,HullML.Howthreemethodsforfixingamedialmeniscalautograftaffecttibialcontactmechanics.AmJSportsMed1999;27:320-8.

10. PalettaGAJr.,ManningT,etal.Theeffectofallograftmeniscalreplacementonintra-articularcontactareaandpressuresinthehumanknee.Abiomechanicalstudy.AmJSportsMed1997;25:692-8.

11. GobleEM.MeniscalAllograftTechnique.OpTechOrthop2000;10:220-6.

12. GobleEM,KohnD,etal.Meniscalsubstitutes–animalexperience.ScandJMedSciSports1999;9:141-5.

13. DeBoerHH,KoudstaalJ.Failedmeniscustransplantation.Areportofthreecases.ClinOrthop1994;306:155-62.

14. VerdonkR,KohnD.Meniscustransplantation:pre-operativeplanning.ScandJMedSciSports1999;9:160-1.

15. BerletGC,FowlerPJ.Theanteriorhornofthemedialmeniscus.Ananatomicstudyofitsinsertion.AmJSportsMed1998;26:540-3.

Instruments are available for purchase or single-use from Stryker Joint Preservation:

SlotInstruments(SingleUse)R2000-004-050

SlotInstruments(Sale)2000-004-050

Additional instruments and materials recommended for procedure:

Smalloscillatingsaw

Meniscalrepairsetandmensicalsutures

Suturepassingnitinolneedle

Straightbiterongueurs(5mmorsmaller)

4mmStrykerFormulaunhoodedroundburr375-940-200

7mmx23mmStrykerBiosteon(HA/PLLA)WedgeInterferenceScrew234-010-161

Asurgeonshouldalwaysrelyonhisorherownprofessionalclinicaljudgmentwhendecidingtousewhichproductsand/ortechniquesonindividualpatients.Strykerisnotdispensingmedicaladviceandrecommendsthatsurgeonsbetrainedinorthopaedicsurgeriesbeforeperforminganysurgeries.

TheinformationpresentedisintendedtodemonstratethebreadthofStrykerproductofferings.Alwaysrefertothepackageinsert,productlabeland/oruserinstructionsbeforeusinganyStrykerproduct.Productsmaynotbeavailableinallmarkets.Productavailabilityissubjecttotheregulatoryormedicalpracticesthatgovernindividualmarkets.PleasecontactyourStrykerrepresentativeifyouhavequestionsabouttheavailabilityofStrykerproductsinyourarea.

StrykerCorporationoritsdivisionsorothercorporateaffiliatedentitiesown,useorhaveappliedforthefollowingtrademarksorservicemarks:Stryker&X3.Allothertrademarksaretrademarksoftheirrespectiveownersorholders.

LiteratureNumber:1000-900-472Rev.AMS/GS03/08

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