关节镜下打结技术PPT演示课件

ArthroscopicknottypingainstructionManual*AnincreasingnumberofsurgeonsareperformingarthroscopicsurgeryinthekneetorepairmeniscaltearsandintheshouldertorepairrotatorcufforlabraltearsManyarealsoperformingcapsularshiftstotreatinstability.EssentialtotheseproceduresistheabilitytotiearthroscopicknotstoapproximateintraarticularIntroduction*ThesurgeonmustsequentiallyconstructtheknotoutsidethejointandthenpasstheknotintothejointthroughsmallcannulasTyingarthroscopicknotsistechnicallydemandingandrequiresconsiderablepracticeWiththepopularityofarthroscopicsurgery,thenumberofusedarthroscopicknotsandthenumberofsurgeonsusingtheseknotshasincreased*KnotTyingPrinciplesThegoalofknottyingistoapproximatetissueundertensionandmaintainthetissueinappositionuntilbiologicrepairandhealingcanoccurItisimperativeforallsurgeonstolearnanduseknot-tyingtechniquesthatminimizethechanceofknotfailure*Knotsecurityfriction,internalinterference,andslackbetweenthrowsFrictionisinherenttothesuturematerialInternalinterferencetheconfigurationoftheknotandincreasedbythelengthofthecontactbetweenthelooplimbandthepostlimbslackbetweentheindividualthrowsineachknottomaximizeloopsecurityslippagecanleadtofailureoftissueappositionKnotTyingPrinciples*fourdifferentprocessesofknotfailureknotslippageandlooseningsuturebreakagetissuefailuresutureanchorpulloutfrombonethroughsuturebreakageKnotfailure*KnotTerminologypostlimb(alsocommonlyknownastheaxiallimb)looplimb(alsocommonlyknownasthewrappinglimb,workingend,runningend,orfreeend)Knotsareconstructedbytyingthelooplimbaroundthepostlimb(Fig.1)*FIGURE1.Loopandpostconfiguration*ArthroscopicKnotPushersAnarthroscopicknotpusherisadeviceusedtoadvancetheloopdownthepostlimbintothejointtocreatetheknot.Arthrexknotpushers.A.Single-hole,B.Double-hole,C.6thFinger*FIGURE3.Mitekknotpushers.A.Single-hole,B.Double-hole,C.Slotted*double-holeknotpushersanddoublediameterknotdouble-holeknotpushersanddoublediameterknotpushersliketheArthrex6thFinger(Arthrex,Naples,FL).Double-diameterknotpushersprovidebetterloopsecuritycomparedtostandardsingle-holeknotpushers*Double-holeknotpusherFIGURE4.Double-holeknotpusher.*HowtoUsetheDouble-DiameterKnotPusherFIGURE5.A-F.TyingknotswiththeArthrex6thfinger*SuturePropertiesTwotypesofsuturesarecommonlyusedintyingarthroscopicknots:apermanent,braided,polyester,nonabsorbablesutureandanabsorbable,monofilamentsutureExamplesofpermanent,braided,polyester,nonabsorbablesuturesareEthibondandTicronExamplesofabsorbable,monofilamentsuturesarePDSII,polydiaxononeandMaxon,polyglyconate*Braidedpolyesterhasincreasedpliability,ductility,ahighercoefficientoffrictionandgreaterstrengththandoesabsorbablemonofilamentBecausethebraidedsutureismorepliable,thevolumeoftheknotisdecreasedandtheseknotscanbecinchedtighter.KnotstiedwithEthibondwereshowntobestrongerwhencomparedtoPDSIIinseveralbiomechanicalstudiesHowever,braidedpolyestermayfraywithexcessivehandling,whichmayleadtosuturerupture*Braidedpolyestersuturemaybecoatedto:improvesurgeonhandlingreducefrictionbetweenthesutureandsurroundingtissue,whichcanleadthetissuedamagedecreasefrictionbetweensuturelimbs,whichmayleadtofrayingHowever,suturecoatingdecreasesthecoefficientoffrictionoftheknot,whichtheoreticallyincreasestheriskofknotslippage*Knotstiedwithabsorbable,monofilamentsuturesareeasiertoslidedownapostanddonotfrayThereislessfrictionbetweenthesutureandsurroundingtissueleadingtolesspotentialtissuedamagewhenthesutureispulledthroughthetissueabsorbablesuturesdissolveanddonotleaveknotsthatmaycauseapersistentinflammatoryreactionaftertissuehealingAbsorbablesuturescanapposetissueunderstressforapproximatelysixweekswithcompleteabsorptionoccurringinapproximatelysixmonths*However,absorbablemonofilamentsuturesarehardertohandlethanpolyestermakingitmoredifficulttokeepknotstightandsecureAlso,aabsorbablemonofilamentsuturewillfailearlierwithcyclicloadingthanpolyestersutureandmayexpandbyplasticdeformationmorethan30%ofitslengthbeforebreaking*Thesizeofthesutureisalsoafactorindeterminingaknot'sholdingcapacityandalsothetensilestrengthofthesutureitselfClinicalfailureofallknotsandsuturetypesimprovedby100%whensuturesizewasincreasedby2gaugesUSP(U.S.Pharmacopeia.ThesizesuturemostcommonlyusedinarthroscopicsurgeryisNo.1orNo.2.*KnotTypesThereareavarietyofknotincludenonslidingknots,slidingknots,andlockingknots.Nonslidingknotsareknotsthatdonotslidethoughthetissuesbeingapposed.TheyincludethesquareknotandknotsconsistingofaseriesofhalfhitchesliketheRevoknot(34)Althoughthesquareknotfailsathigherloadsthandoseriesofhalfhitchesinhand-tiedknots(38),thesquareknotisnotcommonlyusedarthroscopically.*Thesquareknotisaflatknotinwhichbothstrandsenterandleavetheknotparalleltoeachother(Fig.6).Inordertotieasquareknot,symmetrictensionmustbesimultaneouslyappliedtoeachlimb,whichisdifficulttodoarthroscopicallyIfasymmetrictensionisappliedtooneofthelimbs,theknotconvertstotwononidenticalhalfhitchesThus,mostarthroscopicsurgeonspreferusingaseriesofhalfhitches*FIGURE6.Squareknotconfiguration.*Slidingknots,liketheDuncanloop(27),areusefulinopposingtissueundertension.Whiletyingaslidingknot,thepoststrandisheldundertensionwhiletheloopstrandistiedaroundit.Becausethepoststrandisnotincorporatedintothestructureoftheknot,theknot,oncetied,caneasilymovedownthepostresultinginaslidingknotinsteadofaflatknotsuchasthesquareknot.Oncetheslidingknotsareseated,theyareoftenlockedwithaseriesofhalfhitches.Someslidingknotspreferentiallyslideinonlyonedirection*AlockingknotisamodificationofaslidingknotAsimpleslidingknotcanloosenbeforeaseriesofhalfhitchesarethrownto“lock”theslidingknotinplacelockingknots(alsoknownasflipknots)havebeendevelopedtomaintaininitialloopsecuritythatdoesnotloosenwhentensionisremovedThepoststrand“flips,”convertingtheloopstrandintothenewpoststrandandlockingtheknotintoplace.AnexampleofalockingknotistheSMCknot.lockingknotsdonotneedtobesupplementedwithaseriesofhalfhitchesTheauthorsofthismanualhavefoundlockingknotswithoutreinforcinghalfhitchestobeinferiorintensilestrengthtoknotsreinforcedwiththreereversedhalfhitchesonalternatingposts(unpublisheddata)*Lockingandslidingknotscanbeadvancedintothejointjustbypullingonthepost.Thiscancausetensionattherepairsite,whichcandamagethetissuebeingapposed.Tensionattherepairsitecanbeminimizedbypushingtheknotaheadwiththeknotpusherwhilesimultaneouslypullingonthepostlimb.Withlockingandslidingknots,itisimportantthatthelooplimbisatleasttwiceaslongasthepostlimb.Ifitisnot,whenpullingthepostlimbtoadvancetheknotthroughthecannulaandintothejoint,theshortenedlooplimbmaybepulledintothecannulamakingitimpossibletosecuretheknot.Whenusingaslidingorlockingknotconfiguration,itisimportanttoensurethatthesutureslideseasilythroughthetissuebeingopposed.Ifthesuturedoesnotslideeasily,thesurgeonshouldconsiderusinganonslidingknot.*KnotPushingandPullingKnotconfigurationscanbeeitherpushedorpulledintothejoint.hearthroscopicknot-tyingdeviceispositionedonthelooplimbandisadvancedpastthehalfhitchthuspullingtheloopoverthepostlimbintothejoint(Fig.7A).Thearthroscopicknot-tyingdeviceispositionedonthepostlimbbehindtheknotthuspushingtheloopoverthepostlimbintothejoint(Fig.7B).*FIGURE7.A.Knotpulling,B.Knotpushing.*TyingHalfHitchesUsingtheonehandknot-tyingtechnique,halfhitchescanbetiedeitherunderhandoroverhandThefollowinginstructionsdefineanunderhandloopandanoverhandloop*FIGURE8.A-E.Underhandhalfhitch.**ConfigurationofHalfHitchesHalfhitchescanbethrowninthesamedirection(twosuccessiveoverhandhitches)orcanbethrowninoppositedirections(anoverhandhitchfollowedbyanunderhandhitch)Halfhitchescanalsobetiedonoppositeposts.TeraandAberg(37)developedanomenclaturefordescribingflatknots.*PostSwitchingFIGURE13.A.Parallelloopandpostlimbs.B.Parallelloopandpostlimbswitha“flat”knot.*FIGURE14.A.Twistedloopandpostlimbs.B.Whentyingaknotwithtwistedpostandlooplimbs,theknotdoesnotlie“flat.”C.Thefinalknotconfigurationwilllooseniftheknotistiedwhentheloopandpostlimbsaretwisted.*ChanandBurkhartdescribedamayincreasethespeedoftheknot-tyingprocessandalsohelplimittwistingofthesuturelimbs.Onecan“flip”ahalfhitchbyreleasingtensiononthepostlimbandpullingonthelooplimb.Whenthepostisswitched,thedirectionofthehalfhitchisalsoreversed.Theauthorsofthistechniquereportthatitiseasiertofliphalfhitchesusingmonofilamentbecauseitmorereadilyconvertstoaflatknot,butitcanalsobedonewithbraidedsuture.*Holdthepostinthenondominanthandandtheloopinthedominanthand(Fig.15A).Movetheoriginalpostforwardandaheadofthehalfhitch.Applyparalleltractiononthepostandloopsimultaneouslyconvertingthehalfhitchtoaflatknot(Fig.15B).Applyaxialtractiontothelooplimbconvertingitintothenewpostlimbandthehalfhitchisreversed(Fig.15C).*PostSwitchingTechniqueFIGURE15.A-C.Postswitchingtechnique*ArthroscopicKnot-TyingTechniquesItisimportanttodetermineifthesutureslidesthroughthetissueandsutureanchorpriortoknottying.Ifthesuturedoesnotreadilyslide,aslidingorlockingknotshouldnotbeusedandanonslidingknotshouldbechosenOnlyonepairofsuturesshouldbewithintheworkingcannuladuringarthroscopicknottying.Ifmorethanonepairofsuturesarewithintheworkingcannuladuringtying,thereisahighlikelihoodthatthesutureswillbecometwistedandknottyingwillbecomequitetediousifnotimpossible.Additionalsuturesshouldbeshuttledviaamonofilamentsuture(lesstissueabrasion)orbyanarthroscopicgraspertoanaccessoryportalTransparentcannulasarerecommendedforarthroscopicknottying.Thesecannulasallowthesurgeontoseeifthereisanytwistingofthesuturestrandspriortoknottying*ThearthroscopicsurgeonshouldensurethatthereisnoredundantsofttissuearoundthetissuebeingapposedorinthepathofthesuturelimbsbecausethiswillimpedeknottyingandincreasethelikelihoodofknotfailureWhentyinghalfhitcheswithastandardsingle-holeknotpusher,thefirstthrowcommonlyslipswhentheknotpusherisremovedinpreparationforthesecondthrowWhenthesecondthrowisadvanced,thereisachancethatthehitcheswilllockpriortocompleteappositionofthetissueTopreventthis,thesurgeoncanthrowthefirsttwohitchesinthesamedirectionallowingthehitchestoslidedowntheposttoapposethetissueAnothermethodofpreventinginitiallooplooseningistouseadouble-diameterknot-pushingdevice,suchastheArthrex6thtomaintaintensionontheinitialhitchwhilethrowingthesecondhitch*Non-SlidingKnotsFIGURE16.A-F.Squareknot.*RevoKnotTheRevoknotisaseriesofmultiplehalfhitchesmadebyalternatingthepostanddirectionofthehalfhitches.TherehavebeenseveralmodificationstotheRevoknotFIGURE17.A-H.OriginalRevoknot.*TheOriginalRevoknotconsistsoftworeversedhalfhitchesonanidenticalpostfollowedbypostswitchingandtworeversedhalfhitches.Throwanoverhandlooparoundthepost(Fig.17A).Pulltheloopintothejointwiththeknotpusheronthelooplimb(Fig.17B)Withdrawtheknotpusherwhilemaintainingtensiononthepostlimb.Throwanunderhandlooparoundthesamepost(Fig.17C)Pulltheloopintothejointandseattheknotwiththeknotpusher.Oncethetwohitchesareseated,past-pointtocinchtheknotdown(Fig.17D).Switchpostsandthrowanunderhandlooparoundthenewpost(Fig.17E).Pulltheloopintothejoint,seattheknotwiththeknotpusher,andpast-pointtocinchtheknotdown(Fig.17F).Next,throwanoverhandlooparoundthepost(Fig.17G).Pulltheloopintothejoint,seattheknotwiththeknotpusher,andpast-pointtocinchtheknotdown.(Fig.17H)*Snyder'sKnot**Snyder'sKnot*Snyder'sisanothervariationoftheRevoknotThrowanoverhandlooparoundthepost(Fig.18A).Pulltheloopintothejointwiththeknotpusheronthelooplimb(Fig.18B)Withdrawtheknotpusherwhilemaintainingtensiononthepostlimb.Throwanunderhandlooparoundthesamepost(Fig.18C)Pulltheloopintothejointandseattheknotwiththeknotpusher.Oncethetwohitchesareseated,past-pointtocinchtheknotdown(Fig.18D).Switchpostsandthrowanoverhandlooparoundthenewpost(Fig.18E).Pulltheloopintothejoint,seattheknotwiththeknotpusher,andpast-pointtocinchtheknotdown(Fig.18F).Next,throwanunderhandlooparoundthepost(Fig.18G).Pulltheloopintothejoint,seattheknotwiththeknotpusher,andpast-pointtocinchtheknotdown(Fig.18H).Switchpostsandthrowanoverhandlooparoundthenewpost(Fig.18I).Pulltheloopintothejoint,seattheknotwiththeknotpusher,andpastpointtocinchtheknotdown(Fig.18J).*FIGURE19.A-K.Revoknot.**ThecurrentRevoknotisamodificationoftheOriginalRevoknotThrowanunderhandlooparoundthepost(Fig.19A).Advancetheloopwiththeknotpusheronthelooplimbuntilthefirsthalfhitchisseated(Fig.19B).Withdrawtheknotpusherwhilemaintainingtensiononthepostlimb.Throwanotherunderhandlooparoundthesamepost(Fig.19C).Pulltheloopintothejointandseattheknotwiththeknotpusher.Oncethetwohitchesareseated,past-pointtocinchtheknotdown(Figs.19D,E).Throwanoverhandhalfhitcharoundthepostandadvancewiththeknotpusher(Fig.19F).Furthertensionbypastpointingandapplytensiononbothlimbswhileholdingthe(Fig.19G).Switchpostsandthrowanunderhandlooparoundthenewpost(Fig.19H).Pulltheloopintothejoint,seattheknotwiththeknotpusher,andpastpointtocinchtheknotdown(Fig.19I).Switchpostsandthrowanoverhandlooparoundthenewpost(Fig.19J).Pulltheloopintothejoint,seattheknotwiththeknotpusher,andpastpointtocinchtheknotdown(Fig.19K).*SlidingKnotsOverhandThrow*DuncanLoopTheDuncanloopwasoriginallydescribedinthefishingliterature(Uni-Knot)andhasbeenmodifiedforuseinarthroscopicsurgery.ThearthroscopicDuncanloopisalsoknownastheFisherman'sknotortheHangman'sknotThedifferencebetweenthefishingknotandthearthroscopicknotisthedirectiontheloopstrandtravelsaroundthepost.WhentyingthefishingDuncanloop,onewrapsthelooplimbaroundthepostinadirectionawayfromthejoint.TotiethemodifiedDuncanlooporHangman'sknot,thesurgeonsequentiallywrapsthelooplimbaroundthepostinadirectiontowardthejoint*FIGURE21.A-F.FishingDuncanloop.**BerkleyDuncanLoopKnot*ArthroscopicDuncanLoop(Hangman'sKnot)(Fig.22)FIGURE22.A-F.ArthroscopicDuncanloop.*Frenchknot.FIGURE23.A-H.FIGURE23.A-H.Frenchknot.****TheFrenchknot(22)isaslidingknotthatisamodificationoftheDuncanloop.Makethepostlimbhalfaslongasthelooplimb.Graspthesuturesbetweenthethumbandindexfingerofyournon-dominanthand(Fig.23A).Createasmallcircleintheloopstrandbypassingtheloopoverthecombinedpostandloopstrandsandholditbetweenyourthumbandindexfinger(Fig.23B).Makeatotaloffourloopsaroundboththepostandthelooplimbstravelingtowardthejoint(Fig.23C).Passthetailoftheloopstrandoverandthroughthesmallcircleintheloopstrandthatisheldbetweenthethumbandindexfinger(Fig.23D).Passthetailoftheloopstrandunderandthroughtheloopcirclecreatedbythedistalendoftheloopstrandandthecombinedlimbsoftheloopandpoststrands(Fig.23E).Pullonboththelooplimbandthepostlimbsymmetricallytotightentheknot(Fig.23F).Advancetheknotbypullingonthepostlimbwhilepushingtheknotdownwiththeknotpusheronthepoststrand(Fig.23G).Locktheknotwithaseriesofthreealternatinghalfhitcheswithpostswitching(Fig.23H).Throwanunderhandloopontheoriginalpost.Tensionwiththeknotpusher.Switchposts.Throwanoverhandloopoverthenewpost.Tensionwiththeknotpusher.Switchposts.Throwanunderhandloopontheoriginalpostagain.Tensionwiththeknotpusher.TheFrenchknotwasshowntohaveahigherloadtofailurewhencomparedtotheDuncanloopandtheRevoknot*RoederKnotTheRoederknotisaslidingknotthatisavariationoftheDuncanloop.ItwasoriginallyusedintonsillectomysurgeryanddescribedintheGermanliteraturebyRöderin1918Therehavebeenseveralmodificationsoftheknotthathavebeendescribedsincetheinitialdescriptionoftheknot.ModificationsoftheRoederknotarecurrentlyusedinbothlaparoscopicandarthroscopicsurgery*FIGURE24.A-G.Roederknot.*Thepostlimbshouldbeonehalfthelengthofthelooplimb.Throwthefirstlooparoundthepostlimbandthenholdtheloopandposttogetherwiththethumbandindexfingerofthenon-dominanthand(Fig.24A).Throwasecondlooparoundboththepostandlooplimbs(Fig.24B).Throwathirdlooparoundonlythepostlimbandbetweenthepostandloop(Fig.24C).Passthetailoftheloopbetweenthesecondandthirdturnsandinbetweenthelooplimbandthepostlimb(Fig.24D).Tensiontheknotbygentlypullingonboththepostandthelooplimbssimultaneously(Fig.24E).Whilepullingonthepostlimb,pushtheknotintothejointwiththeknotpusheronthepoststrand(Fig.24F).Locktheknotwithaseriesofthreealternatinghalfhitcheswithpostswitching(Fig.24G).Throwanunderhandloopontheoriginalpost.Tensionwiththeknotpusher.Switchposts.Throwanoverhandloopoverthenewpost.Tensionwiththeknotpusher.Switchposts.Throwanunderhandloopontheoriginalpostagain.Tensionwiththeknotpusher.TheRoederknotwasshowntobeinferiortotheDuncanloopandtheSnyderknotinloadtoclinicalfailuretrialsbutastatisticalsignificancewasnotfound(26).*Savoie-ModifiedRoederKnot(Fig.25)*TheSavoie-ModifiedRoederknotisalockingknotinsteadofaslipknotThepostlimbshouldbeonehalfthelengthofthelooplimb.Throwanunderhandlooparoundthepoststrand(Fig.25A).Throwasecondlooparoundboththepostandlooplimbs.Besuretoleaveasmall“hole”inthelooppriortothrowingthesecondloop(Fig.25B).Throwathirdlooparoundboththepostandlooplimbs(Fig.25C).Throwafourthlooparoundboththepostandlooplimbs(Fig.25D).Wrapthelooplimbaroundonlythepostandbringitawayfromthejoint(Fig.25E).Passthetailofthelooplimbbetweenthe“hole”madeinstepC(Fig.25F).Looselytensiontheknotbutdonotpullontheloopstrandorthiswillprematurelylocktheknot(Fig.25G).Whilepullingonthepostlimb,pushtheknotintothejointwiththeknotpusheronthepoststrand.Whentheknotisseated,pushdownontheknotpushertoholdtheknotinplaceandwhilemaintainingtensiononthepoststrand,pullontheloopstrandtolocktheknot.Thiswillpreventtheknotfromlooseningoncetensionisreleasedfromthestrands(Fig.25H).Locktheknotwithaseriesofthreealternatinghalfhitcheswithpostswitching(Fig.25I）*Lieurance-ModifiedRoederKnot(Fig.26)FIGURE26.A-H.Lieurance-ModifiedRoederknot.*TheLieurance-ModifiedRoederknotisalockingknotinsteadofaslipknotThepostlimbshouldbeonehalfthelengthofthelooplimb.Throwanoverhandlooparoundonlythepoststrand(Fig.26A).Throwasecondloopacrossboththepostandlooplimbs(Fig.26B).Throwathirdloopacrossboththepostandlooplimbs(Fig.26C).Wrapthelooplimbaroundthepostonlyandbringitbetweenthepostandlooplimbs(Fig.26D).Passthetailofthelooplimboverandthroughtheinitialloopmadebythepostandlooplimbs(Fig.26E).Looselytensiontheknotbutdonotpullontheloopstrandorthiswillprematurelylocktheknot(Fig.26F).Whilepullingonthepostlimb,pushtheknotintothejointwiththeknotpusheronthepoststrand.Whentheknotisseated,pushdownontheknotpushertoholdtheknotinplaceandwhilemaintainingtensiononthepoststrand,pullontheloopstrandtolocktheknot.Thiswillpreventtheknotfromlooseningoncetensionisreleasedfromthestrands(Fig.26G).Locktheknotwithaseriesofthreealternatinghalfhitcheswithpostswitching(Fig.26H）*LaparoscopicRoederKnot(Fig.27)*TennesseeSlider(Fig.28)FIGURE28.A-F.TennesseeSlider.**TheTennesseeslider(27)isabunt-linehitch,aknotinitiallyusedinsailing,withhalfhitchesthrowninalternatedirectionsonoppositeposts.Thepostlimbshouldbeapproximatelyhalfthelengthofthelooplimb.Throwtheloopoverandaroundthepostlimb(Fig.28A).throwtheloopstrandaroundthepostlimbclosertothejointthantheprecedingloop(Fig.28B).Passthetailoftheloopstrandthroughtheinitialloop(Fig.28C).Tensiontheknotbygentlypullingbothsuturelimbssimultaneously(Fig.28D).Pushtheknotintothejointwiththeknotpusherwiththeknotpusheronthepoststrandwhilesimultaneouslypullingonthepoststrand(Fig.28E).Locktheknotwiththreealternatinghalfhitcheswithpostswitching(Fig.28F).*EasyKnot(Fig.29)FIGURE29.A-E.Easyknot*TheEasyknotisaslidingknotthatconsistsofaseriesoffiveoverhandhalfhitchesthatislockedwithanoverhandhitchontheoppositepost(2).Thepostlimbshouldbeapproximatelyhalfthelengthofthelooplimb.Throwanoverhandhalfhitcharoundthepost(Fig.29A).Throwfouridenticaloverhandhalfhitches.Eachhalfhitchshouldbethrowndistal(fartherfromthejointandarthroscopiccannula)thanthepreviousthrow(Fig.29B).Tensiontheknotbygentlypullingsimultaneouslyonboththepoststrandandloopstrandsimultaneously.Pushtheknotintothejointwiththeknotpusheronthepoststrandwhilesimultaneouslypullingonthepost(Fig.29C).Switchposts.Throwanoverhandhalfhitcharoundthenewpost(Fig.29D).Advancethelockinghalfhitchbypullingthehitchintothejointwiththeknotpusherontheloopstrandandpastpointtocinchtheknotdown(Fig.29E).*LafosseKnot(Fig.30)FIGURE30.A-J.Lafosseknot*TheLafosseknotissimilarinstructuretotheEasyknotbutincorporatesthepostswitchingtechnique.Thepostlimbshouldbeapproximatelyhalfthelengthofthelooplimb.Throwanoverhandhalfhitcharoundthepostwhilemaintainingtensiononthepoststrand(Fig.30A).Throwfouridenticaloverhandhalfhitches.Eachhalfhitchshouldbethrowndistalthanthepreviousthrow.Ensuretomaintaintensiononthepoststrand(Fig.30B).Pushtheknotintothejointwiththeknotpus