DOTTORATO DI RICERCA IN. Scienze Chirurgiche. Ciclo Trentesimo (XXX) TITOLO TESI

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1 Alma Mater Studiorum Università di Bologna DOTTORATO DI RICERCA IN Scienze Chirurgiche Ciclo Trentesimo (XXX) Settore Concorsuale: 06/F4 Settore Scientifico Disciplinare: MED/33 TITOLO TESI Unstable Fractures of the Forearm: a project to improve clinical comprehension and to evaluate the results of the Interosseous Membrane Reconstruction Presentata da: Dott. Cavaciocchi Michele Coordinatore Dottorato Supervisore Prof.ssa Annalisa Patrizi Prof. Andrea Stella Esame finale anno 2018

2 Unstable) Fractures) of) the) Forearm:) a) project) to) improve) clinical) comprehension) and)to)evaluate)the)results)of)the)interosseous)membrane)reconstruction) ABSTRACT) BACKGROUND:) The$relevance$of$the$Unstable$Fractures$of$the$Forearm$treatment$has$emerged$in$the$Literature$just$in$the$ last$four$years,$with$more$and$more$articles$treating$this$complex$subject;$till$now,$few$scientific$evidences$ grew$up.$the$essex$lopresti$lesion$represents$the$worse$pattern$of$the$unstable$fractures$of$the$forearm,$ because$of$the$three$constraints$disruption,$so$it$can$be$defined$as$the$most$challenging$forearm$lesion$for$ the$ surgeon.$ All$ the$ Authors$ agree$ to$ consider$ acute$ treatment$ as$ absolutely$ necessary$ to$ avoid$ all$ the$ problems$deriving$from$the$chronic$pictures,$pointing$out$the$need$for$an$early$correct$diagnosis$of$these$ diseases.$several$surgical$techniques$are$now$described$for$the$treatment$of$theses$triarticular$lesions,$but$ it s$impossible$to$find$a$consensus$on$the$most$valid$one,$because$of$the$exiguity$of$the$treated$patients$ numbers;$different$devices$have$been$described$as$useful$in$the$iom$reconstruction,$but$a$true$superiority$ can t$be$found.$ METHODS:) I$ analyzed$ the$ database$ of$ the$ Orthopedic$ Unit$ of$ Faenza$ Hospital,$ evaluating$ the$ cases$ of$ Unstable$ Fractures$of$the$Forearm:$in$the$period$between$2010$and$2016,$ten$patients$have$been$treated,$all$male,$ with$a$mean$age$of$37$years;$all$the$injuries$had$been$ caused$ by$ high$ energy$ trauma.$ Eight$ cases$ were$ chronic$ EssexQLopresti$ injuries,$ two$ cases$ were$ acute.$ All$ these$ patients$ undervent$ an$ Interosseous$ Membrane$ Reconstruction$ (IOM),$ with$ different$ devices$ (frozen$ allograft,$ LARS,$ Ethibond$ braid$ and$ Ultratape).$ RESULTS:) At$ a$ mean$ follow$ up$ of$ 22$ months,$ the$ mean$ ROM$ for$ the$ acute$ cases$ was$ 5Q140$ degrees$ in$ flexionq extension,$68q0q66 $degrees$in$pronation$and$supionation,$with$no$wrist$functional$limitations;$the$mean$ ROM$in$the$chronic$cases$was$24Q127$degrees$in$extension$and$flexion,$54Q0Q47$degrees$in$pronation$and$ supination,$58$degrees$in$wrist$extension$and$63$degrees$in$wrist$flexion,$without$impairment$in$the$wrist$ movement$in$the$ulnaris$and$radialis$direction.$at$the$same$mean$follow$up,$the$mean$mayo$clinic$elbow$ Performance$ Score$ were$ 89/100$ points$ for$ the$ chronic$ cases,$ result$ that$ can$ be$ defined$ as$ good,$ and$ 97,5/100$points$for$two$acute$cases$(MEPS$result$100$and$95$respectively),$confirming$the$improvement$of$ the$functional$results$in$the$acutly$treated$patients.$no$wrist$pain$persistance$was$referred,$but$we$pointed$ out$ three$ quick$ radial$ neck$ resorptions,$ that$ are$ not$ infrequent$ in$ the$ radial$ head$ prosthesis$ (metal$ monopolar$and$biplar$implants)$with$the$new$pressqfit$desing,$as$widely$stated$by$the$recent$literature.$ CONCLUSIONS:) The$IOM$plasty$is$a$well$planned$technique$and$many$Authors$agree$on$its$use$both$in$acute$and$chronic$ conditions,$ but$ the$ results,$ in$ the$ Literature,$ are$ still$ exiguous$ and$ not$ homogeneous.$ Furthermore$ the$ progression$of$partial$iom$tears$is$still$unknown,$like$the$existence$of$forearm$microintability$that$creates$ condral$erosion$of$the$capitellum$and$stem$loosening$in$the$radial$head$prostheses.$our$encouraging$data$ induce$us$to$continue$on$the$undertaken$road,$with$the$aim$of$validating$the$current$surgical$technique$ and,$if$possible,$of$improving$it$increasingly.$

3 TITLE Unstable Fractures of the Forearm: a project to improve clinical comprehension and to evaluate the results of the Interosseous MembraneReconstruction

4 INDEX Chapter1: Introduction 1.1 TheForearmUnit:AnatomyandBiomechanics 1.2 ClassificationoftheUnstableFracturesoftheForearm 1.3 TheElbowInstability SimpleInstabilityoftheElbow a)biomechanicsofthelesions b)biomechanicsofelbowinstability c)elbowdislocationclinicalexamination ComplexInstabilityoftheElbow a)bonyelbowstabilizers b)radialhead c)olecranon d)coronoid Chapter2:TheclinicalJradiologicalasessmentoftheEssexLoprestisyndrome 2.1 ClinicalAssessment 2.2 Imaging 2.3 TheLongitudinalJTransversalInstabilityManoeuvres Chapter3: SurgicaloptionsintheUnstableFracturesoftheForearm 3.1 AcuteEssexLoprestiSyndrome 3.2 NotesontheRadialHeadprosthesis 3.3 ChronicEssexJLoprestiSyndrome Chapter4: ClinicalexperienceintheUnstableFracturesoftheForearm 4.1 Definitionofthestudy 4.2 ClinicalexperienceandresultsinFaenzaHospitalOrthopedicUnit 4.3 Literaturereview 4.4 Discussion 4.5 Conclusions References

5 CHAPTER1: Introduction ThefirstpaperintheLiterature,discussingtheforearminstabilityafterradialheadexcision,waswrittenby CurrandCoein1946[1],evenifotherAuthorshadpreviouslydescribedthiscondition[2].In1951Peter Essex Lopresti described the proximal migration of the radius following the surgical excision of a comminuted Radial Head fracture, produced bya traumatic axial load from the wrist to the elbow with disruptionofthedistalradiopulnarjoint(druj)andwithruptureoftheinterosseousmembrane.thanks tothisdetaileddescriptionthisinjurygainedtheeponymofessexloprestisyndrome[3].nowadaysthe Essex Lopresti Syndrome, like other traumatic patterns, can be classified into the group of Unstable Fractures of the Forearm, which are characterized by the intrapextrarticular fracture of one or both the forearmbones,associatedwiththeinstabilityofalmosttwoofthethreeforearmconstraints:theproximal RadioPUlnarJoint(PRUJ),theDistalRadioPUlnarJoints(DRUJ)andtheInterosseousMembrane(IOM);these anatomicalandfunctionalstructurescreatetheforearmunit.inthefollowingdiscussionwe llreviewthe anatomyandthebiomechanicsoftheforearmfunctionalunit,theclassificationsoftheunstablefractures oftheforearm,theessexlopresticlinicalpradiologicalassesmentanditssurgicaltreatments. 1.1TheForearmUnit:AnatomyandBiomechanics Theforearmcanbeconsideredasasinglearticulatingjoint,wheretheinterdependenceofthedifferent anatomical structures allows forearm rotation and elbow and wrist motion [4, 5]. These functions, expeciallythepronationandthesupination,explainthecomplexintegratedrelationshipsbetweenbones andsofttissuesalongtheentireforearmlength. A complete knowledge of the biomechanics is essential for the correct management of the Unstable FracturesoftheForearm.AnalyzingtheelbowPforearmkinematic,wehavetocarefullyconsidertheroleof stabilizers both for flexionpextension and pronationpsupination. The Lateral Ulnar Collateral Ligament (LUCL) and the Medial Collateral Ligament (MCL) stabilize the elbow in flexionpextension; the Annular Ligament, the Squared Ligament (also called Denucè Ligament), the Interosseous Membrane and the TriangularLigamentcontroltheforearmpronationandsupination.AnnularandDenucèSquaredligaments arethestabilizersofproximalradiopulnarisjoint(pruj).interosseousmembrane(iom)isanextrarticular complexstabilizeroftheforearmunitmidportion.theanatomicalstudiesfindanagreementdescribingthe IOM as composed by five ligamentous components: Proximal Oblique Weitbrecht Cord, Dorsal Oblique Accessory Cord, Central Band, Accessory Band, Distal Oblique Bundle. The two proximal ligaments (ProximalObliqueCordandDorsalObliqueAccessoryCord)contrasttheRadialHeadanteriordislocation [6]andchangesubstabtiallyinlength,ifcomparedwiththedistalthreeligaments(CentralBand,Accessory BandandDistalObliqueBundle)[7],thatareisometric,becausetheulnarattachmentsarelocatedalmost on the axis of the forearm rotation. The Central Band (CB) is the most important IOM portion: it is approximatively17mmx10.6cmanditsmechanicalresistance(13.1+/p3.0n/mm)isstrongerthanallthe otherpartoftheiom;cbhasatenislemodulusof608.1+/p160.2mpa,itselongationatbreakingpointis 9.0 +/P 2.0 [8] and it has an istological composition made of Collagene for the 84 (an intermedate structurebetweenmembraneandligament).cbarisesfromtheinnerridgeofradialdiaphysis(about7.7 cmfromrh)andsteerstothejunctionbetweenthemiddleandthedistalthirdoftheulna(13.2cmfrom the olecranon tip) [9], with an oblique angle of 20P25 compared to the ulnar axis. The Distal Oblique Bundle (DOB) can be found in the 40 of human subjects, it arises from the inner part of distal ulnar diaphysisanditruns,withanoppositeobliquitythancb,totheulnarsideofradialmetaphisys.thedob

6 givesacontributioninthestabilizationofthedistalradioulnarjoint[7]anditcontraststhelongitudinal migrationoftheulna.triangularfibrocartilage(tfcc)isanintrarticularsuspensorligamentofthedistal RadioPUlnarJoint(DRUJ).ThebiomechanicalroleofIOMandTFCCistomaintaintheaxialforearmstability: afteranexperimentalrhexcision,theforearmstabilityisprovidedbytheiomforthe71andbythetfcc forthe8;fromtheseconsiderations,it seasytounderstandhowasignificantproximalmigrationofthe radiusoccursifradialheadandbothiomandtfccaredisrupted. The Forearm Ligaments have an function: to stabilize the two bones in the transverse and in the longitudinalplane,bytransferringloadsfromtheradiustotheulna.radiusandulnaareroughlyparallel andconnected,ateachend,byawellpconstrainedjoint,and,inthemidportion,bytheiom.thesystemis relativelytightandisdifficulttoinjureoneofthesestructureswithoutaffectinganotherpartofthesystem. Ulnaranatomyisrelativelysimple,contrarytotheradius,thathasamorecomplexstructure:Sagepointed out the angles and curves complexity of the radial bone [10].The Radius has four small but significant curves:twoonthefrontalplane(about13 proximallyand6 inthemiddleshaft)andtwointhesagittal plane(about13 proximallyand9 inthemiddleshaft).thesecurvesgiveitthetypical bowshape,that representthebiomechanicalconditiontocrossovertheulnainpronation,maintaining,atthesametime,a relativetensionoftheiominallthepositions.schemitschandrichards[11]confirmedtheimportanceof theradialbowrestorationtowarrantacorrectforearmfunctionafterafracture.iftheradialcurvesarenot anatomicallyreconstructed,theforearmloosesthepossibilitytoachievethefullpronationandagoodgrip strength. The normal range of motion has been described as 71 P75 of pronation and 82 P84 of supination, with the ulna essentially fixed by its proximal anatomy (ulnophumeral joint) and the radius capableofalargemovementatthedruj,drawinginthespaceasimplecone,withitsaxisrunningroughly from the center of the radial head to the center of the distal part of the ulna.. Two conditions must be fulfilled to allow a correct movement in pronation and supination: an equal longitudinallengthofradiusandulna,withnormallocationandamountoftheradialbow,andastable relationshipbetweentheradiusandulnaattheproximal,middleanddistalradiopulnarjoints. 1.2ClassificationoftheUnstableFracturesoftheForearm In2007MarcSoubeyrand[12]describedthe ThreeForearmConstraints concept:theforearmunitmust beinterpretedlikeanassociationofthreeconstraints,pruj,iomanddruj,eachonefundamentalforthe stability and, consequently, for the movement of the forearm itself. The lesion of one constraint (distal radius fracture, simple RH fracture, sinostosis ) causes a decrease in pronation and supination, without instability(soubeyrand sstage1).thelossoftwoconstraintscreatesapartialtransverseinstability(crissp Crossinjury,Galeazzilesion,Monteggialesion,Soubeyrand sstage2).thelesionofallthethreeforearm constraintsbringstoalongitudinalandtransverseforearminstability(essexploprestilesion,soubeyrand s Stage3).Thelattertwopatterns(CrissPCross,Galeazzi,MonteggiaandEssexLoprestiLesions)definethe UnstableFracturesoftheForearm. Ifweconsidertheonsettiming,anEssexLoprestiLesioncanbeacuteorchronic:animmediateproximal translationlargerthan5mm.associatedwithamultipfragmentedradialheadfractureissignificativeforan acutecompleteirreparableiomlaceration.aprogressiveradialmigrationafteraproximalresection(more than 4 weeks from the trauma) or a painfull RH prostheses with DRUJ instability/discomfort and grip weaknessissignificativeforachronicessexloprestiinjury,wherewecansupposeapartialiomtearatthe beginning,thatbecameacompletetearaftertherepetitivetractionsofthebicepsbrachii[13j15].thelast patternhasbeennamed MissedEssexLopresti byjungbluth[16]:thisdefinitionstartedadiscussionin

7 the Literature around the early loosening and the painfull RH prostheses, as a clinical expression of a missed diagnosis of forearm instability. In 2006 Pfaeffle [17] described the Ligamentoplasty (IOM reconstruction) as a way to decrease the loads applied by a radial head prostheses to the capitellum. RecentlyDuckworth[18]presentedacaseserieswitha28ofRHprostheseslooseninginasixyearfollow up,thathehypotizedcouldbecausedbyaforearmmicroinstability.someauthors(soubeyrand,pfaeffle, Jungbluth, Osterman [12, 16, 17, 19]) recommend a Ligamentoplasty in acute and chronic longitudinal instability of the forearm. The IOM reconstruction both in acute and chronic Essex Lopresti lesions can correctmacrodeformitiesandinstability(ulnarplusatdruj,radialmigrationatpruj)ormicrodeformities and progressive instabilities (painfull RH reconstruction or substitution by capitellum cartilage erosion, wristdiscomfort). 1.3TheElbowInstability 1.3.1SimpleInstabilityoftheElbow Theelbowisthesecondjointofthehumanbodyinorderofdislocationfrequencyinadults,but,inthe childhood,isthemostdislocatingjoint;theelbowstabilityiswarrantedbyacomplexequilibrium,thatalot ofinjurypatternscanbreak.theanatomicalstructuresprovidingelbowstabilityare: PLateralStabilizers: LateralUlnarCollateralLigament(main) RadialHead(secondary) Epicondylartendonsandmuscles(secondary) PAnteriorStabilizers: Coronoidandanteriorcapsule PMedialStabilizers: MedialCollateralLigament(main) Epitrochleartendonsandmuscles(secondary) PPosteriorStabilizers: Olecranonandposteriorcapsule The elbow instability is created by the lesion of one or more of these structures: as the numbers of structuresinvolvedincreases,thelesionpatternbecomesmoresevere,withtrueelbowdislocations,that canrepresentanorthpedicemergency,incaseofnervesorvesselsimpairment. BIOMECHANICSOFTHELESIONS Nowadaysit swidelyacceptedthatthefundamentalmodelofelbowinstabilityistriggeredbyaposterop lateralrotationalmechanism:theelbow,infact,duringafallontheextended(orpartiallyflexed)armwith theforearminsupination(thatrepresentthemostfrequentfallenmechanisminthesetraumas),fromthe momentthehand arrives ontheground,undergoesanincreasingcompressiveaxialloadwiththebody approachingtotheground;onthisfulcrum,thebodytendstoundergoaninternalrotation,which,atthe upperlimb,translatesintoanexternalrotationoftheforearm,thatremainsinthesupineposition(holding thehandwiththepalmfacingtotheground). Sincethemechanicalaxisonwhichtheelbowisworking during this fall is positioned laterally, with respect to the articulation itself, the sum of the forces determines,attheelbowjoint,astressinvalgusandinsupination,which,addedwithaxialload,isableto determineasubluxationoratruedislocation,withaposterolateralrotatorymechanism.

8 The first Authors to suggest this biomechanical mechanism were Osborne and Cotterill [20], which demonstrated the constant presence of the lesion of the Lateral Collateral Ligament and of the lateral elbowcapsuleinpatientswithrecurrentelbowdislocation,and,atthesametime,describedgoodclinical results with the surgical repair of the lateral elbow structures, based on the biomechanical pattern of posterolateralrotatoryinstability,whichwaslaterbetterdefinedandbroughttotheforebytheclinicaland thebiomechanicalstudiesconductedbythegroupofmayoclinicandinparticularbyo'driscoll[21].this typeofmechanismexposesthejointstructurestocompressiveand"cutting"forcesthatcancreate not onlychondrallesions,butalsofracturesofintrinsicbonestabilizers,determiningthepatternofcomplex elbowinstability,whichwewillwidelydescribeinthenextparagraph. BIOMECHANICSOFELBOWINSTABILITY Elbowinstabilitybiomechanicswaspreciselyoutlinedin1992byO'DriscollandMorrey,whoproposeda circularpatternofprogressiveelbowstabilizersdestruction,dividedintothreestages,whichincreasewith thetraumaseverity[22]:oncedefinedtheposterolateralrotatoryinstability(plri),everyvalgusstresswith supinationandaxialloadcausestotheelbowseverallesionsthatoriginateinitslateralpart,whichisthe onewiththemaximumstress;instage1thelesionofthelateralulnarcollateralligament(lucl)occurs, which determines an elbow subluxation. As the trauma s energy increases, the soft tissue lesion mechanism progresses circularly: in stage 2, the breakdown of the remaining portions of the LUCL is associatedwiththeruptureofbothanteriorandposteriorjointcapsule,creatinganincompleteposterop lateral elbow dislocation, that often conventional radiograms are not able to diagnose, as the coronoid remains perched on the troclea. If the trauma energy increases, the disruption continues on the medial elbow compartment (stage 3): the posterior part of the Medial Collateral Ligament is torn, allowing the elbow to reach a lateral dislocation, by the posterolateral rotatory mechanism: the joint is completely dislocated, rotating around the anterior band of the Medial Collateral Ligament, which remains the last intact structure (stage 3A); in stage 3B also this structure is injured and the instability mechanism is complete:nothingcanopposetheelbowdislocation,whichcanbedirectedposteriorly(morefrequently) oranteriorlyandthereductioncannotbemaintained. In summary, dislocation is the ultimate event of a pathological instability mechanism of three degrees, whichoriginatesinthelateralsideoftheelbow,thatissubjectedtothegreaterstressduringoverweightin valgus,supineandaxialload,andwhichextendstotheremainingelbowjointcomponents;thephysiology ofeachstagecorrelateswiththeanatomicallesionframeworkandwiththeleveloftherelatedinstability. Simpleelbowinstabilitycanbeassociatedwithcartilagedamage,vascularinjuryandVolkmann'ssyndrome orcompartmentalforearmsyndrome,duetotheextensiveischemicdamageofthesofttissues.thelate complicationsconcerntheromdecreaseandtheformationofperiparticularossification. ELBOWDISLOCATIONCLINICALEXAMINATION Inthecaseofapatientwithposteriorelbowdislocation,thisshouldbereducedinsupination,tominimize thetraumaonthecoronoidandonthemedialelbowaspect,wheretheremaystillbesomenotpinjured softtissues;themayoclinicindicationssuggesttoreducetheelbowundergeneralanesthesiaoratleastin narcosis[21],astheneedtomimictheinjurymechanismandthetractionsrequiredexposethepatientto animpressivepainfulexperience;thereductionmanoeuvreisaforcedsupinationinextension,applyinga forceinvalgusandtractionontheelbowtoreleasethecoronoid;atthispoint,thetruereductionismade inflexionandvarus,whilemaintainingtraction.oncetheelbowisreducedtoananatomicalposition,after XPrayconfirmation,itisnecessarytotestthedegreeoftheresidualinstability,throughmanoeuvresthat evaluatethestabilityinvarus,invalgusandintheposteroplateralmechanism.aforcedpronationposition

9 is capable of minimizing instability degree 1, 2 and 3, as it uses the intact remaining fibers of Medial CollateralLigamentasaboulder;thestabilityinvarusandvalgusisfirstlytestedinfullextension,thenin incremental flexion degrees (greater than 30 in order to release the olecranon from the olecranic pit, avoidingitsstabilizingeffect).theposterolateralrotatoryinstabilityistestedbyperformingthepivotshift lateral elbow test: a supine patient with an elevated arm is evaluated bringing the elbow to a stress in valgus and supination with increasing flexion rates; in the patients able to relax or in the ones under generalanesthesia,oncetheflexionproceeds,apalpableandaudiblenoiseappears,determinedbythe joint reduction. If the articulation is stable or moderately stable in flexion, a conservative treatment protocolcanbeundertaken,butifthejointrestsunstable,evenathighflexionrates,thesurgicaltreatment withopenreductionandcapsularandligamentreconstructionisneeded[21] ComplexInstabilityoftheElbow ThecomplexelbowinstabilityisdefinedbyMorrey,thefirstauthortohavesystematizeditsbiomechanics, asaconditionthatcauseselbowinstabilityduetothepresenceoflesionsinthearticularbonestructures andinthecapsularandligamentouscomponentsoftheelbow[23,24]. BONYELBOWSTABILIZERS Thecontributionthatthetwocollateralligamentscanprovidetoanintactelbow,againstthevarusand valgusstress,isabout50alongtherom[25];theonlyexceptionistheelbowinfullextension:inthis casetheligamentcontributionisabsentandthestabilityisdeterminedjustbythebonystructuresofthe ulnophumeral joint (olecranon and coronoid) and by the anterior capsule. Since the contribution to the elbow stability given by soft tissues (ligaments, joint capsule) in the rotatory mechanisms has been discussedinthepreviousparagraph,inthisone wewillfocusjustontheelbowbonestabilizers,whose valueisnowwellconsolidatedintheliterature[26]. RADIALHEAD As already stated above, the radial head has a role of secondary elbow stabilizer: a functional Medial Collateral Ligament, in fact, is the main opponent of a deforming force in valgus and it is widely demonstrated that, in the case of a resected radial head with an intact MCL, the elbow does not show instability [26]; after a MCL lesion, the stability against the deformations in valgus is warranted by the humeralpradialjoint.inaddition,theintimatecorrelationbetweentheradialheadandtheulnarportionof thelateralcollateralligamentmakestheradialheadafundamentalstabilityfactoragainsttheposterop lateralrotatoryinstabilitymechanisms[27].theradialhead,evenifbiomechanicallyisasecondaryelbow stabilizer,hasacentralroleagainstbothvalgusstressandposterolateralrotatoryinstability(plri),sothe anatomicalosteosynthesisortheprostheticreplacementarefundamentaltorestorethejointstability. OLECRANON Olecranon is crucial in supporting the loads across the forearm, in particular in the axial direction, as demonstrated by experimental studies which have shown that the removal of more than 50 of the olecranonstructurecreatesanirreversibleelbowdislocation[28].

10 CORONOID Experimental and clinical studies have shown that it is necessary to have at least 50 of the coronoid integritywiththeradialheadconserved,inordertomaintainelbowjointstabilityandfunction:acoronoid injurywithfracturedorremovedradialheadmakesthearticulationseverelyunstable[23].

11 CHAPTER2: TheclinicalJradiologicalassesmentoftheEssexLoprestisyndrome An appropriate treatment of the Essex Lopresti lesion requires a complete knowledge of the forearm stabilitybiomechanicsandaclinicalcomprehensionofthiscomplexpattern,withtheaimtoobtainanearly diagnosis,bothinacuteandinchroniclesions.whenthepatientpresentsarhcomminutedfracture,the clinicianmustconsiderthepossibilitytofaceanessexploprestilesion. 2.1ClinicalAssesment AnIOMdisruptioniseasilymissedinthepatientswithEssexLoprestilesion,firstlybecausetheclinician can trelyontheusualimagingtechniques:theclinicalhistoryandthephysicalexaminationofthepatients areessentialtodiagnoseanessexloprestilesion.thetraumamechanismisusuallyaviolentaxialloadon theforearm;thetypicalpatientisamale,hardworkerorathlete,withastoryofanhighpenergyfalldown. Thecommonestsymptomsinaprimaryorsecondaryforearminstabilityare:painintheposterioraspectof thewrist(increasedwithforearmsupination)andintheelbow,whentheproximalpartoftheradiusabut against the capitellum; loss of range of motion, mainly in forearm supination and in wrist extension; evidence of posterior prominence of the distal ulna at the wrist (fixed subluxation); hand grip and pronationweakness,withforearmdiscomfortifmanipulatedbytheclinician;apprehensionattheelbow valgusmanoeuvres,becauseofpainfulinstability. Theclinicalevaluationstartsfromtheelbowstability:anEssexLoprestilesionusuallyshowsaLateralUlnar Collateral Ligament tear, sometimes associated with a Medial Collateral Ligament lesion. Drawer, Pivot Shift,ValgusandVarusPPronationTests(alsofluoroscopyassisted)aretheusualmanoeuvrestoperform. Onceevaluatedtheelbow,theclinicianmustanalyzetheforearm:intheacutelesions,theIOMpalpationis difficultbecauseofthepain,picturealreadysuspectforthediagnosis;inthechronicpattern,wesuggestto performthe CPFingers comparativetest:thearmliesonatablewiththeelbowflexetat90degreesand theforearmverticaltothefloorplane;theclinicianusesthethumb,inoppositiontotheotherfingers(like a C letter),tosqueezetheforearmspaceandpushalternativelythedorsalandthevolarside,evaluating themuscularpiomresistanceinpronationandinsupination;thetestmustbecomparativewiththehealth side andcould beinvalidated byastrongmuscularhypertrophy and byasignificantedema.weusually checkaclinicaltendernessatthemiddlethird(centralband)andatthemoredistalpart(dorsaloblique Band)oftheforearm:anyresistancelossofoneormoreforearmpartsissuspectforapartialorcomplete IOMtear.Thelastclinicaltesttoperformit sthedrujstabilityevaluation;theforearmrotationdecreases becauseoftheanatomicaldislocationoftheulna,thatloosesitsnormalpositioninthesigmoidnotchof theradiusandbecomessubluxeddorsallyanddistally;inaddition,thewristextensionisblocked,because the distal ulna impinges upon the dorsal carpus. The physician tests the DRUJ with the dorsalpvolar comparativetranslationoftheulnainneutralposition,insupinationandinpronation. 2.2Imaging Wemustconsiderthatatwomillimiterstranslationoftheradiusintheproximaldirectionusuallyoccurs afteraradialheadexcision,withoutclinicalsymptoms.otherwise,aradiustranslationbiggerthan10mm createsconsiderablefunctionalimpairment.

12 PXPray:aposteroPanteriorandlateralviewofelbowandwristaremandatory,aswellasgripviewofboth wrists.thegripview canbehelpfulindetectingdynamicradialshortening,thatrepresents achangein ulnarvariancewiththeactivefunctionoftheforearm.toobtainacorrectgripviewseries,it snecessaryto putthewristsinpronationandthexpraybeamdirectedwithanangleof15degreescentredonthedruj. Another XPray of the wrists should be taken in the same pronated position, while the patient grip a dynamometerat20kg.,ifthepainallowsit. Pdynamicfluoroscopicevaluation,whichdemonstratethepossibilityofcorrectingforearmlongitudinal instability,applyinganaxialtraction. PUltrasound comparative and dynamic study: this method is quicker and less expensive than MRI and allowsadynamicevaluationoftheinterosseousmembrane. PMRIdepictsthestaticanatomicalstatusoftheIOManditstears,buttheresultofthisexamcanbe invalidatedbyartifacts,duetothetraumaeffectsortopreviousforearmsurgicalprocedures. 2.3TheLongitudinalJTransversalInstabilityManoeuvres Axialstresstest[29]:itconsistsofamanualtractionunderanesthesia,appliedthroughthehandandthe wrist;withtheforearminthesupineposition,theshoulderisabductedat90 andinternallyrotated,the elbowisbendedto90 andtheforearmisheldinneutralrotation.alongitudinaltractionisappliedandan XPray study is performed to the wrist and the elbow with a lateral comparative view, before and after traction:adistalradialmigrationof5mmshouldbeconsideredasignofinstability. The MuscularHerniaSign [30]:duringadorsalforearmultrasoundexaminationunderanesthesia,an anteropposteriorpressionisappliedbythephysicianontheanteriorsideoftheforearm:iftheinterosseous ligament is torn, the volar muscles pass through the disrupted IOM, creating the typical images of a muscularhernia.thetestmuststudythecentralbandanddorsalobliqueband. RadiusPullTest[31]:thistesthasbeenplannedusingcadavermodels,aftertheexperimentalexcisionof therhandthefollowingdisruptionofiomandtfcc.intheclinicalpractice,thistestisperformedduring thesurgicaltreatment:apositivepulltestprovidesaproximalradialmigration>=3mm;themigrationof6 mmormoreisobservedingrossinstabilityoftheforearmwithinjuriesoftheiomandofthetriangular fibropcartilagecomplex(tfcc). PIntraoperative Radius Joystick Test [32]: It s a manoeuvre to test the longitudinal and the tranversal stabilityoftheforearmduringsurgery;theprocedureissimilartothesmith sone.theforearmisplacedin maximalpronationandthearmisheldfirmlytoimmobilizethehumerus.aclampisplacedontheradial neckandpulledlaterally,usingmoderateforce.thetestispositiveiftheproximalradiusmoveslaterally. Thetestisnegativeiftheradiusremainsstable(positivepredictingvalue90,negativepr.value100). TheclinicalinstabilitymanoeuvresarethefundamentalstepinthediagnosisofanEssexLoprestiinjury: thisisourassessmentprotocol:preoperativetime:1)elbowstability,iom CPFingers Test;2)fluoroscopic and ultrasound dynamic forearm evaluation (Axial stress test; Muscular Hernia Sign); 3) comparative dinamicdrujstresstest.intraoperativetime:4)radiuspulltest;5)radiusjoysticktest.

13 Thesemanoeuvresarehighlysensitivefortheacutelesions,buttheyprovideusefulinformationsalsoin chronic patterns, bringing useful informations on the possibility to correct the forearm longitudinal and transversalinstabilitywithrhreplacement,ulnarshorteningosteotomiesandiompdrujplasties.

14 CHAPTER3: SurgicaloptionsintheUnstableFracturesoftheForearm Earlydiagnosis is mandatory because the treatment of the nstable fractures of the forearm in the early phases shows better outcomes than in the late ones. The aim of surgical treatment is to restore the triarticularforearmrelationshipby: restoringboneslength reconstructingoftheiomcentralband stabilizingdrujandpruj Proximalradialmigrationisapproximatively5mminacuteand10mminchronicEssexLoprestiinjuries. Bonelengthequalizationcanbeobtainedinacutethroughtheradialheadreconstructionorsubstitution, checkingthedrujreduction.inthechronicpatternswesuggestalwaystoperformanulnarshorteningand toinsertaradialheadprosthesesifthecapitellarcartilageishealthyandwhenthelongitudinalforearm instabilityhasbeencorrected. Multiple techniques have been described for the Central Band reconstruction: MarcotteandOstermanin2007definedanalgorithmforthemanagementofacuteandchronicinstabilities [19]; they performed an IOM reconstruction both in acute and in chronic lesions, also in presence of a radial head prosthesis. These Authors used originally a BonePPatellar TendonPBone autograft for Central Band plasty in the chronic cases; this procedure is currently being performed using bonepligamentpbone allograft,eliminating,inthisway,thedonorpsitemorbidity.severaltendongraftsandsinteticdeviceshave beendescribedforthetreatmentofforearminstability.skahenetalusedpalmarislongusorhalfofthe Flexor Carpi Radialis tendon, but these grafts donot provide adeguate strenght for the Central Band reconstruction[33].achillestendonallograftrestoresapproximately50ofthetransferringforcesofthe nativeiom,asdemonstratedbytomainoetal[34].sellmanetal[35]andsaboetal[36]describedtheuse ofnylonropetoperformaflexiblecentralbandreconstructionandfoundthatthisconstructcouldrestore the stiffness, but only when the radiocapitellar articulation had been restored. Finally, Kuzma et al [37] describedtheclinicaluseofthepronatorterestoreconstructthecentralband. OursurgicalpracticeinFaenzaOrthopedicUnit,aftersomecasesofTibialisPosteriorgraftatthebeginning of our experience, actually does not provide for allografts, because of the host reaction risk and of the absence of tendon synovialization, contrary to what happens in the intrarticular ligamentous reconstructions.furthermore,thetendonsrequireaprecisemeasurelengthandlargertunnels,thatcan weakentheulna,soweactuallyuseanumber2ethibondnonabsorbablebraid,passing1.5mmradiopulnar tunnels;wecanaffirm,takingintoconsiderationourandliteraturedata,thatotherdevicesareeffective too, even if often more expensive. The fixation may be done with miniplates or titanium interference screws. ThebiomechanicalfeaturesofIOMplastytechniquesare:thelongitudinalforearmstabilizationperformed bytheplasty(severalsurgcalproceduresallowthetransversestabilization),theisometricbehaviourofthe graftduringthepronationandthesupination,theprecisioninthelengthandinthestraightresistanceof thegraft,thesafetyofthesurgicalprocedurefromneurovascularinjuriesand the reproducibilityofthe technique. DRUJ plasty is needed when the comparative dorsalpvolar subluxation is evident. In chronic lesions, an arthroscopic debridement allows a better equalization between radius and ulna; several sophisticatedopenorscopictechniquesareavailablefordrujtreatmentbutwehavetoconsiderthat,ina

15 so challenging surgery (RH reconstruction/substitution, IOM plasty, ulnar shortening osteotomy, DRUJ plasty) an easier procedure have to be preferred, to avoid an increase in the surgical times and in the tissues exposition. In the cases of major DRUJ instability, during the Essex Lopresti repair surgery, we suggestatransientpinning,tocontroltheexactforearmlength. DealingwiththePRUJplasty,theLiterature and our case series didn t show an absolute indication to a proximalforearmstabilizationintheessexloprestilesions.weusedaradialloopplasty,usuallywithan autologustricepsfascia,insomeveryunstabletransverseforearminstabilitywithulnarorradialmalunion. WeagreeinapreciseclinicaldiscriminationbetweenAcuteandChroniclesionsandrecomendanaccurate preoperatoryevaluation. 3.1AcuteEssexJLoprestiSyndrome(<4weeks). Thesurgicalplan,inthesecases,isbasedon: P Radial Head reconstruction or replacement: if the radial head fragmentation does not allow a stable synthesis, the prosthesis is the best choice: it must be placed in line with the ulnar sigmoid notch. The Kocker approach is our preferred. Unsatisfactory results of the radial head prosthesis can result from residual forearm longitudinal microinstability, with pain and risk of stem loosening. A radiological transparency around the stem is a not rare event: wenoteda stable and widely movable elbow with a progressiveradialneckbonereabsorption,withoutcasesofprostheticloosening.tocontrastsmilarevents, somecompaniesareintroducingmacroporousstraightstems,thatshouldimproveintrinsicstabilityofthe implants;theloosepfitstemsremainanusefuldevice,avoidingfromthestartthiskindofproblems. PElbowLigamentsreconstruction:afteracorrectperformanceoftheclinicalstestforelbowstability,under fluoroscopy, is frequent to find a lesion of the Lateral Ulnar Collateral Ligament and/or of the Medial Collateral Ligament: we suggest to suture both the ligaments, mainly when a RH prosthesis has to be implanted.aresidualelbowinstability,afterasubstitution,canbethecauseofcapitellarchondrallesions. PIOMplasty:MarcotteandOsterman[19]didn tusetheirtechniqueintheacuteessexloprestiinuries.we prefertoapplyatreatmentsimilartosoubeyrand sprocedure:incorrespondenceofthemaximumradial bow and in the opposite part of the inner ridge, under brilliance, a five centimetres incision is made. CrossingbetweenflexorPextensormuscles,thePronatorTeresradialdistalheadisrecognized;maintaining anintermediateforearmrotation,a1.5millimetersdrillisadressed,witha20degreesaxis,comparedto thelongitudinalforearmaxis.thechoosendevicefortheiomplastycrossesdorsallytheforearmbones, undertheextensorscompartment.wesuggesttousealigamentpasser,likeinthekneesurgery.underxp raycontrol,thedeviceisstretched,forearmmovementandrhpistoningarecheckedandthesystemis finallyfixed.aspreviouslydecribed,weuseanumber2ethibondbraided,sowefixtheneopligamentwith atwopholesstailesspsteelplate(handsurgeryplate)withthreewirestiedbyitself;incaseofnecessity,is possibletountietheknotandtoretensionit. DRUJPlasty:ifDOBLigamentisintact,surgicalprocedureisnotmandatory.InDRUJinstabilityadouble parallelpinning(wristinfullsupination)isrecommended;wesuggestthepinsremovalafter3p4weeks,to avoidwriststiffness. 3.2NotesontheRadialHeadprosthesis TheLiteratureexpressesawideconsentfortheuseoftheradialheadprosthesesincasesofnonPrepairable fractures, which require the removal of the radial head; this is especially true when other bone lesions

16 (coronoid and olecranon fractures) or ligamentous lesions are associated with the fracture of the radial headwithinthesopcalled"complexelbowinstability"[21,23,27,38,39]. The radial head replacement is necessary both in the Complex Elbow Instabilities and in the Unstable FracturesoftheForearm(forthelatterpattern,mostofallintheacutecases),becauseofthehighriskof instabilityworseningwiththesimpleradialheadexcisionandinordertopreventtheoccurrenceofsevere forearminstabilityinthetransverseandlongitudinalplanes.overtheyears,awidevarietyofimplantshave beenproposedtoreplacetheradialhead[40]:themodernimplantsaremostlymadeofmetal.actually, morethantenradialheadprosthesismodelscanbefoundonthemarket,whichcanbedividedinthree different types, depending on the design of the proximal portion: Unipolar (with cylindrical heads), Anatomical(havingfixedheadswithanatomicdesign)andBipolar(withmobilecylindricalheads). FromtheLiteraturedataandfromthecommonexperienceofthesurgeons,it snowadaysimpossibleto define the best implant on the market: Unipolar implants with loosepfit has their advantages (no radiotrasparencyorresorptionaroundthestem,goodmotionthankstotheloosefit)anddisadvantages (overstuffing difficult to prevent, stem lenght just short), and the same can be said for the Anatomical prosthesis(morerespectforhead sanatomy,difficultimplanttechnique, radiotrasparency or resorption aroundthestem)andforthebipolar(easierinsertion,selfpalignmentoftheradialheadwiththecapitellum [41],radiotrasparencyorresorptionaroundthestem,polyethylenewear). 3.3ChronicEssexJLoprestiSyndrome(>4weeks). Thechoiceofthesurgicaloptiondependson:thereducibilityfrompositivetoneutraloftheulnarvariance atthewrist(longitudinalinstability),thetimepassedfromthetraumaandthethestabilityofthedruj (TransverseInstability). Thesurgicalplanisbasedon: Elbow ligamentous reconstruction: frequently the lateral compartment can be repaired, if the tissue maintainsagoodconsistency,orreconstructedwithgraft,incaseofpoorqualityoftheresidualtissue; usuallyepicondilaraugmentationisperformed.themedialcollaterallegament,oncetorn,isdifficultto repair,soitusuallyneedsareconstructionwithgraft. Radial Head Prosthesis: in case of previous Kaplan approach, a Posterior Radial Branch isolation with electrostimulation,toassessitsvalidity,issuggested.theradialheadimplant,ifneeded,canbeperformed following the usual procedure. In the chronic patterns, the implant of a radial head prosthesis is not mandatory,evenintheunstableelbows,becauseawellplannedulnarshortening,aniomreconstruction andadrujplastycansupporttheforearmtensionswithoutaperformingradialhead. PUlnarShorteningOsteotomy(USO):inthetreatmentofthechronicEssexLoprestiSyndromewesuggest toalwaysperformanulnarshorteningosteotomy,withtheaimtodecreasethecompartments tension. The osteotomy length is calculated on the residual ulnar variance at the wrist, after a radial head prosthesis, if necessary, or on the complessive bones length discrepancy, after an Axial Stress Test. The procedure begins from the 3 rd medium of the diaphysis: firstly, the ulnar tunnel for ligamentoplasty is prepared,thenthecalculatedbonecylinderisresectedandacompressionosteosinthesiswithplateand screwsisperformed.

17 P IOM Plasty: in the chronic cases ligamentoplasty is clearly recommended, following the technique previouslydescribed.forthecorrectplanning,onthesurgicalfield,ofulnarosteotomyandiomplasty,we suggestatemporarydrujpinning. PDRUJPlasty:asalreadypointedoutintheprecedingparagraphs,severaltechniquehavebeendescribed, bothopenandarthroscopic.inessexloprestitreatment,weusethefulkersonpwatsontechnique,avery simpleandquickprocedure,whichuseatendon,autograftorhomograft,passedinaloopfigurearound theulnarneck[42].weuseoneortwo2.4mm.anchorsattheulnarsurfaceoftheradialmetaphisistofix the loop. Other techniques can be performed: Darrach, SouveePKapandji and Synostosis [43] are used operations,buttheyshouldbeconsideredassalvageprocedures.

18 4.1Definitionofthestudy CHAPTER4: ClinicalexperienceintheUnstableFracturesoftheForearm FollowingtherulesofBolognaUniversityforthefinalproject(thesis),thisdataanalysisdoesnotrequire anypermissionfrominstitutionalreviewboard,becauseofthedidacticpurposesofthethesisitself.this procedure has been applied taking into consideration that all the clinical data had been collected in an enabledhealthcarefacility(aziendausldellaromagna). Tesi& non& notificata& al& Comitato& Etico& in& quanto& finalizzata& all acquisizione& di& competenze& di& natura& metodologica&per&il&raggiungimento&di&finalità&didattiche. 4.2ClinicalexperienceandresultsinFaenzaHospitalOrthopedicUnit I analyzed the database of Dr. Maurizio Fontana (Chief of the Orthopedic Unit of Faenza Hospital), evaluating the cases of Unstable Fractures of the Forearm: in the period between 2010 and 2016 ten patientshavebeentreated,allmale,withameanageof37years;alltheinjurieshadbeencausedbyhigh energytrauma.eightcaseswerechronicessexploprestiinjuries,twocaseswereacute. Thefirstthreecases,atthebeginningoftheexperience,weretreatedforanIOMreconstructionwithan allograftofposteriortibialtendon(frozenallograftfromrizzoliinstitutetissuebank,bologna,italy),but thehighdiameteroftheradialandulnartunnelsneededfortheseimplants,withtheconsequentriskof bonelesions,droveustolookforadifferentplastytechnique,withtheaimtoreducethedimensionsofthe useddevice.followingthispurpose,theremainingpatientsweretreatedwithdifferentdevices:theforth patient had an IOM plasty with an artificial ligament (LARS, Ligament Augmentation and Reconstruction System,ArcsurTille,France),thefifthonereceivedanEthibondbraid(EthiconUS,Sommerville,NJ,USA) andthelastfiveweretreatedwithasuturetapedevice(ultratape,polyethyleneuhmw,smith&nephew, London UK). The patient treated with the Ethibond braid suffered the acute rupture of the IOM plasty deviceandneededarevisionsurgerywithultratape,withgoodresults. Sixoftheeightpatientsofthechronicgroupunderwentanulnarshorteningosteotomyandoneofthissix receivedalsoaradialheadprosthesisremoval,becauseofthechroniccapitellarimpingementwithasevere cartilagedamage.atameanfollowupof22months,themeanromfortheacutecaseswas5p140degrees inflexionpextension,68p0p66 degreesinpronationandsupionation,withnowristfunctionallimitations; the mean ROM in the chronic cases was 24P127 degrees in extension and flexion, 54P0P47 degrees in pronation and supination, 58 degrees in wrist extension and 63 degrees in wrist flexion, without impairmentinthewristmovementintheulnarisandradialisdirection.atthesamemeanfollowup,the mean Mayo Clinic Elbow Performance Score were 89/100 points for the chronic cases (due to approximatively18 lessinsupination,maybederivingfromimperfectligamentisometryanddrujplasty absent),resultthatcanbedefinedasgood,and97,5/100pointsfortwoacutecases(mepsresult100and 95 respectively), confirming what we stated in the previous chapters, about the improvement of the functionalresultsintheacutlytreatedpatients.nowristpainpersistancewasreferred,butwepointedout threequickradialneckresorptions,thatarenotinfrequentintheradialheadprosthesis(metalmonopolar andbiplarimplants)withthenewpresspfitdesing,aswidelystatedbytherecentliterature[44j45].the MEPSisaclinicaltestuniversallyusedtoassestheelbowfunction,butitisnotexcellentforthestudyof theforearm.weresearchedintotheliteraturefortheexistenceofforearmspecificclinicaltests,without

19 results;severaltests,thatanalyzethewholesuperiorlimbinitsfunction,arewelldescribed,butnonewith aspecificdestinationfortheforearm.basedontheseconsiderations,weproposedanewforearmscore (ForearmItalianPerformanceScore,FIPS),thatanalyzespain,jointsmotion,jointsstability,gripstrenght, radiological evidence and functional status. FIPS test is still under scientific validation from the Italian SocietyforShoulderandElbowSurgery(SICSeG)andfromtheHandSurgeryItalianSociety(SICM),sowe decidedtoavoiditsuseinthisstudy,preferringtofollowthealreadyvalidatedclinicaltests. 4.3Literaturereview During our clinical experience of IOM reconstruction a continuous review of the Literature has been performed,withthegoalofacontinousmaintainanceofthehighestscientificlevelinthetreatmentofour patients.weperformedthelastrevisionoftheliteraturethe20thofnovember2017,usingpubmed.gov, looking all the articles dealing with our subject. The research for IOM AND reconstruction found 29 articles:aftertheabstractsreading,justsevenofthemwereinherentinthestudyorinthetreatmentof the Unstable Forearm Fractures (Essex Lopresti injuries). Two of theese articles [46J47] were based on cadavericmodelstudy,withoutanalysisofinvivotreatment;onearticle[48]dealtwitharevisionofthe biomechanicandclinicalliterature,analysingthedifferentdevicestorebuiltthecentralband.theother four articles were clinical studies that analysed the treatment of chronic Essex Lopresti syndrome with differentdevices.gasparetal[49]inveryrecentworkanalysedtencasesofchronicessexloprestilesions, dividingtheminto twogroups,thefirstcomposedoffivecases,treatedwithasinglepbundletechnique, versusotherfivecases(secongroup),treatedwithadoublepbundleiomreconstruction;inallthecasesthe deviceusedwasaminiptightrope(arthrex,naples,fl,usa).theresultsweredefinedasgoodforallthe patients;theforarmrotationwassignificantlybetterinthesinglepbundlegroup,whilethemaintenanceof ulnar variance was better in the doublepbundle group, with the Authors preference for this latter technique.mealsetal[50]performedareviewoftheliteratureforthedifferentreconstructiontechniques andpurposedacasereportofiomplastyinachronicessexploprestiinjury,usingasuturepbuttondevice, reportinggoodresultsatashorttermfollowup.thegroupofgasparandosterman,inapreviouswork [51],performedaretrospectivereviewoftenpatientwithchronicEssexLoprestisyndrome,treatedwith ulnarshorteningosteotomy(uso)andiomreconstructionwithminitightropedevice(arthrex,naples,fl, USA):atameanfollowupof34.6monthssignificantimprovementswereobtainedinelbowROM,wrist flexionpextension, QuickDASH score and ulnar variance, but three cases failed, requiring further surgical treatments (one revision of ulnar shortening osteotomy for persisitent impingement, one revsion with ulnarosteotomydeviceremovalforthelostinforearmsupinationandonefixationofaradialshaftfracture after a fall). The last article of this review was written by Grassmann et al [52]: they analysed twelve patientsaffectedbyessexloprestiinjury,confirmedbymri,treatedbydrujreductionandstabilization with temporary KPwires and, in addition, radial head replacement in eight cases and radial head reconstructionintwo;atameanfollowupof59monthstheclinicalresultsweredefinedasgood,basedon MayoModifiedWristScore,MayoElbowPerformanceScoreandDASHscore. In the same date (20 th of November 2017) we performed a further PubMed.gov research, using as Keywords: Essex Lopresti AND treatment, obtaining 136 articles; 71 articles treated calcaneal diseases (weretheeponymofessexploprestiiswidelyusedforthecontributionofthisauthorinthedefinitionof the foot pathologies). The remaining 65 articles, were evaluated by the abstracts reading: taking into considerationtheaimofourstudy(iomreconstructiontechniquesandtheirresults),wedecidetoexclude: articleswritteninlanguagesotherthanenglish,casereports,reviewarticleswithoutaclearanalysisofthe Essex Lopresti syndrome treatment, anatomical descriptive articles, articles dealing with imaging techniques,historicalarticlesandthepurelydescriptiveclinicalarticles.attheendofthisselection,just15

20 articleswerechosenfortherelevanceofthesubject,inaccordancewithourmatter.fiveofthis15articles had been yet cited and discussed in our previous chapters and paragraphs [19, 47, 48, 51, 52] so we analysedtheremainingten,brieflydiscussingalsotheresultsoftheworkfrommarcotteandosterman [19],whichhadnotbeenpointedoutinthepreviouspages;theseAuthors[19]publishedtheirresultsof sixteenpatients,allaffectedbychronicessexloprestilesions,atameanf.u.of78months;nopatients needed secondary surgery, grip strength improved from 59 to 86 of the unaffected limb, no sign of worseningwasreportedintermsofpainorfunctionthanbeforethesurgery,but15ofthe16patientshad improvedwristpain.schnetzkeetal[53]recentlyperformedaretrospectivereviewofthirtyponepatients with EssexPLopresti injury, analysing the differences in the early diagnosed and acutely treated patient (sixteen, treated with DRUJ pinning stabilization in supination for six weeks) and the cronic diagnosed, underliningthebetterresultsoftheacutegroup,withnotsignificativedifferencesinelbowandwristrom inthetwogroups.bigazzietal[54]recentlydescribedtheiriomreconstructiontechniquewithafascialata allograft,expressingpromisingearlyresultswithaneasyandreproduciblesurgicaltechnique,thatavoid donor site disease. Matson and Ruch [55] proposed their surgical technique, based on radial head prosthesis,iomreconstructionwithaproantorteresautograft,usoandtfccrepair,buttheydon trefer anyclinicaldata.milleretal[56]describedtheshortresultsoftheiriomreconstructiontechniquewitha biceps button and a tenodesis screw, aiming to biologically reconstruct and anatomically tension the centralbandoftheinterosseousmembrane.venouziouetal[57]purposedacombinationofradialhead replacementandulnarshorteningosteotomyinsevenpatient,affectedbychronixessexploprestilesion;at ameanfollowupof33months,theypointedoutgoodclinicalresultsatthescoresused(mepsandmws), with elbow and wrist ROM improvement. Heijink et al [58], belonging the Mayo Clinic group, described eightcasesofchronicessexploprestiinjury(delayofthetreatemntofmean3.3years),firstlytreatedwith monobloc radial head prosthesis, with five failures within three years; the three failures with implant aseptic loosening, underwent a cemented bipolar implant, with longpterm better results: the Authors themselvesdefineasanimperfecttreatmenttheonlyradialheadprosthesisinthesecomplexcases.adams etal[59]in2010purposedaniomcentralbandreconstructionwithaboneppatellartendonpbonesystem in chronic EssexPLopresti injuries. Chloros et al [60] in 2008 purposed a complete triarticular forearm treatmenttechnique,consistingofradialheadreconstruction,levelingofthedistalradiopulnarjoint,plasty ofthecentralbandoftheinterosseousmembrane,usingapronatorteresreroutingtechnique,andfinally repair of the triangular fibrocartilage complex: these Authors defined this technique as useful, but challengingandrequiringexcellentsurgicaltechnique.soubeyrandin2006firstlydescribedhisinnovative IOMcentralbandreconstructiontechnique[61]:thisarticleisabiomechanicalstudyonfrozencadaver,but wehaveincludedit,beeingthebasisforoursurgicaltechnique.finally,ruchetal[62]in1999describeda techniqueforthetriarticularforearmreconstructionofessexploprestiinjuryafterradialheadexcision:they purposedatechniquefortheplastyofthecentralbandinconjunctionwiththesurgicalrepairofthedruj andwiththeradialheadprosthesis,addressingallthethreeanatomicalstructuresthatprovidelongitudinal stabilityoftheforearm. 4.4Discussion TherelevanceoftheUnstableFracturesoftheForearmtreatmenthasemergedintheLiteraturejustinthe lastfouryears,withmoreandmorearticlestreatingthiscomplexsubject;tillnow,fewscientificevidences grew up: all the Authors agree to consider acute treatment as absolutely necessary to avoid all the problemsderivingfromthechronicpictures,pointingouttheneedforanearlycorrectdiagnosisofthese diseases.severalsurgicaltechniquesarenowdescribedforthetreatmentofthesestriarticularlesions,but it simpossibletofindaconsensusonthemostvalidone,becauseoftheexiguityofthetreatedpatients

21 numbers;differentdeviceshavebeendescribedasusefulintheiomreconstruction,butatruesuperiority can tbefound. We have compared our experience with the ones of the Literature main Authors, drawing overlapping conclusions:thekeystonetoachieveaviablefunctionalrecoveryoftheforearmistheearlydetectionof theinjury,which isbasedmuchmoreontheclinicalassessmentthanontheimaging,soeveryclinician mustsuspectanessexloprestisyndromeinfrontofanhighenergytraumawithprujlesionandpainat theforearmandatthedruj.thetreatmentofthechronicessexloprestilesionsisasalvageprocedure, requiringasurgicaltechniquenoteasytoperforminchargeofpruj,iomanddruj.duringourexperience wehavefoundavalid surgicalprotocoloftreatment,thatatthemomentwehaveappliedmoreinthe chronic cases (eight) than in the acute ones (two): first, we prepare the radius for the radial head prosthesis,leavinginsituthetrialimplant,second,weproceedwithanulnarshorteningosteotomy,third, we insert the definitive radial head prosthesis, trying to equalize the forearm longitudinally, fourth, we performaplastyofthedruj;inasinglecaseofchronicessexloprestiinjurywithapainfulradialhead prosthesis,weremovedthisimplantandwedecidedtoavoidanewprosthesis,becauseofthecapitellar cartilagesuffering.intheacutecases,theradialheadcanberepaired,ifpossible,orreplaced,incaseof complex fractures; LUCL and MCL must be tested clinically and radiologically under anesthesia and eventually surgically explored, because every lesion of the elbow stabilizers should be, in our hands, repared;weperformiomplastyasexposedinthepreviouschaptersandfinally,incaseofdrujinstability, weperformapinninginfullsupinationfor3/4weeks.thistreatmentprotocolgaveusgoodresultsinthe chronic cases and excellent results in the two acute cases; our results and the confirmations we have obtainedfromtheliteratureinthelastyearsdriveustoproceedintheapplicationofourstudiestothe patients. TheBiasesofthisstudyareclear:thelownumberofthepatientsthatwehadtreated,thelackofdivision betweentheacuteandthechroniccases,thedifferencesintheuseddevicesduringourexperienceandthe absenceofspecificandvalidatedclinicaltestsfortheresultsdefinitionoftheclinicforearmtreatments. 4.5Conclusions The fracturepdislocations of the Forearm must be classified as Unstable Fractures of the Forearm, because they damage the functional Units of the Forearm: Monteggia, Galeazzi, CrissPCross Injury and EssexPLopresti lesions must be included in this group, becausetheintrapextrarticular fractures of one or both the forearm bones are associated with instability of almost two of the three constraints. Correct clinical evaluation and early surgery are critical for the success of the treatment of this lesions; late treatmentsareoftenrelatedtopooroutcomes. TheEssexLoprestilesionrepresentstheworsepatternoftheUnstableFracturesoftheForearm,because of the three constraints disruption, so it can be defined as the most challenging forearm lesion for the surgeon: radial head reconstruction/substitution and DRUJ stabilization are well known and spread procedures.theiomplastyisawellplannedtechniqueandmanyauthorsagreeonitsusebothinacute and chronic conditions, but the results, in the Literature, are still exiguous and not homogeneous. Furthermore the progression of partial IOM tears is still unknown, like the existence of forearm microintability that creates condral erosion of the capitellum and stem loosening in the radial head prostheses.

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24 32SoubeyrandM,CiaisG,WassermannV,KaloucheI,BiauD,DumontierC,GageyO.TheintraJoperative radiusjoysticktesttodiagnosecompletedisruptionoftheinterosseousmembrane.jbjsbr2011;93jb, 10:1389J SkahenJR3rd,PalmerAK,WernerFW etal.reconstructionoftheinterosseousmembraneofthe forearmincadavers.jhandsurg(am)1997;22(6):986j994 34TomainoMM,PfaeffleJ,StabileKetal.Reconstructionoftheinterosseousligamentoftheforearm reducesloadontheradialheadincadavers.jhandsurgbr2003;28(3):267j270 35Sellman DC, Seitz WH, Postak PD, et al. Reconstructive strategies for radioulnar dissociation: a biomehanicalstudy.jorthoptrauma1995;9(6):516j522 36SaboMT,WattsAC.Reconstructingtheinterosseousmembrane:atechniqueusingsyntheticgraft andendobuttons.tchhandupextremsurg2012dec;16(4):187j193 37Kuzma G. Reconstruction of the Essex Lopresti Injury. 2003; AAHS 33rd annual meeting. Kaui, Hi, january8j11 38 Morrey BF. Radial head fracture. In: Morrey BF, editor. The elbow and its disorders. 3rd ed. Philadelphia:WBSaunders;2000.p.341J64 39BeingessnerDM,DunningCE,StacpooleRA,JohnsonJA,KingGJ.Theeffectofcoronoidfractureson elbowkinematicsandstability.clinbiomech(bristol,avon).2007feb;22(2):183j90.epub2006nov13 40ZunkiewiczMR,ClementeJS,MillerMC,BaratzME,WysockiRW,CohenMS.Radialheadreplacement withabipolarsystem:aminimum2jyearfollowjup.jshoulderelbowsurg.2012jan;21(1):98j104 41YianE,SteensW,LingenfelterE,SchneebergerAG.Malpositioningofradialheadprostheses:anin vitrostudy.jshoulderelbowsurg.2008juljaug;17(4):663j70 42 Purisha H, Sezer I, Kabakas F, Tuncer S, Erturer E, Yazar M. Ligament reconstruction using the FulkersonJWatsonmethodtotreatchronicisolateddistalradioulnarjointinstability:shorttermresult. ActaOrtopTraumatTurcica2011;45(3):168J174 43AllendeC,AllendeB.PostraumaticoneJboneforearmreconstruction:areportofsevencases.JBJS 2004;86A:364J O'Driscoll SW, Herald JA. Forearm pain associated with loose radial head prostheses. J Shoulder ElbowSurg.2012Jan;21(1):92J7.doi: /j.jse Epub2011Aug19. 45RotiniR,MarinelliA,GuerraE,BettelliG,CavaciocchiM.Radialheadreplacementwithunipolarand bipolar SBi system: a clinical and radiographic analysis after a 2Jyear mean followjup. Musculoskelet Surg.2012May;96Suppl1:S69J79.doi: /s12306J012J0198Jz.Epub2012Apr18 46WernerFW,LeVasseurMR,HarleyBJ,AndersonA.RoleoftheInterosseousMembraneinPreventing DistalRadioulnarGapping.JWristSurg.2017May;6(2):97J101.doi: /sJ0036J Epub2016 Jun20 47DrakeML,FarberGL,WhiteKL,ParksBG,SegalmanKA.Restorationoflongitudinalforearmstability usingasuturebuttonconstruct.jhandsurgam.2010dec;35(12):1981j5.doi: /j.jhsa

25 48MatthiasR,WrightTW.InterosseousMembraneoftheForearm.JWristSurg.2016Aug;5(3):188J93. doi: /sj0036j epub2016jun13 49GasparMP,KearnsKA,CulpRW,OstermanAL,KanePM.SingleJversusdoubleJbundlesuturebutton reconstructionoftheforearminterosseousmembraneforthechronicessexjloprestilesion.eurjorthop SurgTraumatol.2017Oct6.doi: /s00590J017J2051J4.[Epubaheadofprint] 50MealsCG,ForthmanCL,SegalmanKA.SutureJButtonReconstructionoftheInterosseousMembrane. JWristSurg.2016Aug;5(3):179J83.doi: /sJ0036J Epub2016Jun20 51 Gaspar MP, Kane PM, Pflug EM, Jacoby SM, Osterman AL, Culp RW. Interosseous membrane reconstruction with a suturejbutton construct for treatment of chronic forearm instability. J Shoulder ElbowSurg.2016Sep;25(9):1491J500.doi: /j.jse Epub2016Jun30 52Grassmann JP, Hakimi M, Gehrmann SV, Betsch M, Kröpil P, Wild M, Windolf J, Jungbluth P. The treatmentoftheacuteessexjloprestiinjury.bonejointj.2014oct;96jb(10):1385j91.doi: /0301j 620X.96B SchnetzkeM,PorschkeF,HoppeK,StudierJFischerS,GruetznerPA,GuehringT.OutcomeofEarlyand LateDiagnosedEssexJLoprestiInjury.JBoneJointSurgAm.2017Jun21;99(12):1043J1050.doi: /JBJS BigazziP,MarenghiL,BiondiM,ZucchiniM,CerusoM.SurgicalTreatmentofChronicEssexJLopresti Lesion:InterosseousMembraneReconstructionandRadialHeadProsthesis.TechHandUpExtremSurg. 2017Mar;21(1):2J7.doi: /BTH MatsonAP,RuchDS.ManagementoftheEssexJLoprestiInjury.JWristSurg.2016Aug;5(3):172J8.doi: /sJ0036J Epub2016Jun20 56MillerAJ,NaikTU,SeigermanDA,IlyasAM.AnatomicInterosseusMembraneReconstructionUtilizing the Biceps Button and Screw Tenodesis for EssexJLopresti Injuries. Tech Hand Up Extrem Surg Mar;20(1):6J13.doi: /BTH Venouziou AI, Papatheodorou LK, Weiser RW, Sotereanos DG. Chronic EssexJLopresti injuries: an alternative treatment method. J Shoulder Elbow Surg Jun;23(6):861J6. doi: /j.jse Epub2014Apr22 58HeijinkA,MorreyBF,vanRietRP,O'DriscollSW,CooneyWP3rd.Delayedtreatmentofelbowpain and dysfunction following EssexJLopresti injury with metallic radial head replacement: a case series. J ShoulderElbowSurg.2010Sep;19(6):929J36.doi: /j.jse Epub2010Jun17 59Adams JE, Culp RW, Osterman AL. Interosseous membrane reconstruction for the EssexJLopresti injury.jhandsurgam.2010jan;35(1):129j36.doi: /j.jhsa ChlorosGD,WieslerER,StabileKJ,PapadonikolakisA,RuchDS,KuzmaGR.ReconstructionofessexJ lopresti injury of the forearm: technical note. J Hand Surg Am Jan;33(1):124J30. doi: /j.jhsa SoubeyrandM,OberlinC,DumontierC,BelkheyarZ,LafontC,DegeorgesR.Ligamentoplastyofthe forearm interosseous membrane using the semitendinosus tendon: anatomical study and surgical

26 procedure.surgradiolanat.2006jun;28(3):300j7.epub2006feb11 62RuchDS,ChangDS,KomanLA.Reconstructionoflongitudinalstabilityoftheforearmafterdisruption of interosseous ligament and radial head excision (EssexJLopresti lesion). J South Orthop Assoc Spring;8(1):47J52

27 Image&1:&clinical&case&of&a&chronic&Essex&Lopres6&syndrome& Male,&42&y.o.,&right?handed,&car&accident,&right&forearm&involved& X?rays&6&weeks&aEer&the&trauma& X?rays&6&months&aEer&the&surgery& Clinical&result&6&months&aEer&the& surgery,&meps&85/100&

28 Image&2:&clinical&case&of&an&acute&Essex&Lopres6&syndrome& Male,&43&y.o.,&leE?handed,&bike&accident,&leE&forearm&involved& X?rays&in&E.R.&90&minutes&aEer&the&trauma:&PRUJ,&IOM&and&DRUJ& lesions&are&evident& X?rays&aEer&the&surgery& Clinical&result&6&months&aEer&the& surgery,&meps&95/100&

29 Image& 3:& Painful& radial& head& removal& and& IOM& reconstruc6on& in& a& chronic& case& of& Essex& Lopres6& syndrome& On& the& surgical& field,& the& radial& head& prosthesis& had& lost& its& press?fit& with& the& radial& bone& and& had& created& a& severe& chondral& damage& on& the& chondral& surface& of& the& capitellum,& so& it& was& removed& and& not& replaced& IOM&plasty&with&a&Posterior&Tibial&Tendon&(allograE)&