Rev. bras. ortop. vol.51 número5

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SOCIEDADE BRASILEIRA DE ORTOPEDIA E TRAUMATOLOGIA

w w w . r b o . o r g . b r

Original

Article

Functional

and

radiological

evaluation

of

acute

acromioclavicular

dislocation

treated

with

anchors

without

eyelet:

comparison

with

other

techniques

夽

Alexandre

Tadeu

do

Nascimento

∗

_,

_Gustavo

_Kogake

_Claudio

HospitalOrthoservice,GrupodeOmbroeCotovelo,SãoJosédosCampos,SP,Brazil

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Articlehistory:

Received7November2015 Accepted23February2016 Availableonline30August2016

Keywords:

Acromioclavicularjoint Sutureanchors Treatmentoutcome

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Objective:Toassesstherepairresultsofacromioclaviculardislocations(ACJD)gradesIIIand

V,withanchorswithouteyelet,whencomparedwithothertechniques,andtoevaluate factorsthatcanaffectthefinalresult.

Methods:Aretrospectivestudyof36patientswithACJDgradesIIIandVintheRockwood classification,12treatedwithanchorswithouteyelet,11withonetightrope,sixwithtwo tightropes,andsixwithsubcoracoidcerclage,operatedfromSeptember2012toFebruary 2015.PatientswereassessedradiographicallyandthroughDASH,UCLA,thevisualanalog scaleofpain(VAS)andtheShort-Form36(SF-36).Surgicaltimeandthepossibleinfluence ofsomefactorsintheoutcomewerealsoassessed.

Results:ThemeanDASHscorewas6.7;UCLA,32.9;VAS,1.2;andSF-36,79.47. Radiographi-cally,thefinalmeanmeasurementwas9.93mm,withnostatisticaldifferencebetweenthe groups.ThemeansurgicaltimeforGroupIwas31min;GroupII,19min;GroupIII,29min; andGroupIV,59min.TherewasasignificantdifferencebetweenGroupsIIandIVwhen com-paredwiththestudygroup.Theinitialandimmediatepost-operativeACJDmeasurements ACJDwerecorrelatedwiththefinalmeasure.

Conclusion: TherepairofacuteACJDwithanchorswithouteyeletisaseffectiveastheother methods,withsignificantlyshorteroperativetimewhencomparedwiththesubcoracoid cerclagetechnique.Thefinalradiologicalresultisinfluencedbythecoracoclavicularinitial distanceandtheimmediatepostoperativemeasurement.

夽

StudyconductedattheHospitalOrthoservice,GrupodeOmbroeCotovelo,SãoJosédosCampos,SP,Brazil.

∗ _{Corresponding}_author_.

E-mail:nascimento@icloud.com(A.T.Nascimento).

http://dx.doi.org/10.1016/j.rboe.2016.08.015

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visualanalógicadedor(EVA)epeloShort-Form36(SF36).Otempocirúrgicoeapossível interferênciadealgunsfatoresnoresultadofinaltambémforamavaliados.

Resultados: Amédiadosescoresfoide6,7noDASH;32,9noUCLA;1,2naEVAe79,47no SF-36.Radiograficamente,amedidafinalmédiaentreocoracoideeaclavículafoide9,93mm, semdiferençaestatísticaentreosgrupos.Quantoaotempocirúrgico,amédiadogrupoIfoi de31minutos;dogrupoII,19minutos;dogrupoIII,29minutosedogrupoIV,59minutos, houvediferençasignificativaentreosgruposIIeIV,quandocomparadoscomogrupoem estudo.AmedidainicialdaLACeamedidapós-operatóriaimediata(POI)tiveramcorrelação comamedidafinal.

Conclusão: OreparodaLACagudacomâncorassemeyeletétãoeficazquantooutros méto-dosecomtempocirúrgicosignificativamentemenorquandocomparadocomatécnicade amarrilhosubcoracoide.Oresultadoradiológicofinaléinfluenciadopeladistância coraco-clavicularinicialedoPOI.

Introduction

The true incidence of acromioclavicular joint dislocations (ACJD)isnotknown,sincemanyaffectedindividualsdonot seektreatment.Approximately12%ofalldislocations involv-ingtheshoulderaffecttheacromioclavicularjoint.

Athleteswho participateincontactsports (e.g.,football, rugby, martial arts) are at higher risk. ACJD is the most commonreasonwhyathletesseekmedicalcarefollowinga traumaticeventintheshoulder;glenohumeraldislocationis thesecondmostfrequentcause.1,2

Menaremorecommonlyaffected,withanapproximate ratioof5:1,3_and_younger_subjects_(<35_years)_present_this

con-ditionmoreoften,mainlyduetotheirgreaterparticipationin high-riskactivities.Malesinthesecondtofourthdecadesof lifehavethehighestfrequencyofACJDandpresent,inmost cases,partialinjuriesoftheligaments.3

Dependingontheseverityofthetrauma,anindividualmay injureoneoralloftheligaments,leadingtodifferentdegrees ofACJD.1 _The_most_commonly_used_{classification}_is_that_of

Rockwood,4_which_stratifies_this_condition_into_six_types.

Themainfunctionoftheacromioclavicularjointandits ligamentsistosustainthescapulaandconnecttheupperlimb totheaxialskeleton.InACJD,thisconnectionislost;dueto gravity,thearmbecomeslowerrelativetotheclavicle,which canleadtogreatercontactoftheacromiononthetendonof thesupraspinatusmuscleandthuscausesymptomsofimpact andtendoninjury,neurologicalsymptomsduetotractionof thebrachialplexus,anddyskinesiaofthescapula.5,6

OneofthefirstmethodsofACJDtreatmentwasfixation withKirschnerwiresafterclosedreduction.Thistechnique givesgoodresults,butithasnotbeenroutinelyuseddueto rarebutpotentiallyfatalcomplicationsthatcanoccurdueto breakageandmigrationofmaterial.7

There are several surgical techniquesfor treating acute ACJD; coracoclavicular fixationwith subcoracoid ligationis oneofthemostcommonlyused.Theliteraturepresents stud-ies that compare the biomechanical differences of several techniques,butfewcompareclinicalandradiological differ-encesintheresultsofthevariousmethods.8

OneoptionforthesurgicaltreatmentofACJDisthe cora-coclavicular stabilization using sutureanchors fixedin the coracoidprocess,tyingtheknotsintheclaviclethroughbone tunnels.9,10

Resultswiththistechniquearedivergentintheliterature duetoapossibleroleoftheanchoreyelet(Fig.1),which pre-cipitates the breakage ofthe wire, thus causing procedure failure.11

Theuseanchorswithouteyelet(Fig.1),inwhichthe high-strengthwireexitsdirectlyfromtheanchoritself,maybea solutiontothisproblem;theanchorismadeofamaterial sim-ilartothatofthewire,avoidingthecontactofthelatterwith amorerigidmaterialthatcouldbreakit.

Material

and

methods

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Fig.1–Differencebetweenanchorswitheyelet(arrow)andwithouteyelet.

surgeonatasinglecenterbetweenSeptember2012and Febru-ary2015,wereretrospectivelyreviewed.Age,gender,side,and ACJDclassificationdistributionisshowninTable1.Thestudy includedpatientswithshouldertraumawhohadACJDgrades

IIIor V,and who were operatedinupto 30daysfrom the timeofinjury.In additiontoconventional radiographs(AP, scapulaprofile,andaxillaryprofile),allradiographsfor diag-nosisweremadeintheorthostaticposition,withaweightof 2.5kgoneachlimb,featuringbothacromioclavicularjointsin sameimage(Fig.2).Theminimumfollow-uptimewassetas sixmonths.Theexclusioncriteriaintheselectionofpatients comprisedcasesofACJDgradeIV,casesassociatedwith frac-turesatothersitesoftheshouldergirdle,andcasesthatwere operated30daysafterinjurydate.

Surgicaltechnique

Surgerywasperformedwithpatientundergeneral anesthe-siaandbrachialplexusblock,inabeachchairposition. An incisionofapproximately 2–3cm(Fig.3)wasmadedirectly onthedistalendoftheclavicle,whichwasosteotomizedin its distal0.5cm and removed together with the meniscus, asdescribedbysomeauthorsinspecificcases.12 _Anteriorly

tothe clavicle,thecoracoidwas digitallyidentifiedby pal-pation, i.e., without directvisualization,the authors would positionthe anchorinsertionguide directlyon itssuperior face.Twodouble-loaded2.9-mmanchors(Juggerknot-Biomet) wereusedinallcases.Fourbonetunnelswerecreatedinthe clavicleusinga2-mmdrill,2cmfromtheendoftheclavicle; tunnelsweresquare-shaped, with1cmbetweenthem.Two

Fig.2–Standardstressradiographypresentingthe acromioclavicularjointsinthesameimage,demonstrating anACJDVtotheleft.

wireswerepassedthrougheachofthemtorepairthe dislo-cation.Withthesesamewires,thedeltoidandtrapeziuswere reinserted;theseareoftenaffected,mainlyinACJDgradeV

lesions.

Postoperativeperiod

Patientsremainedincontinuousimmobilizationwithasling forsixweeks,afterwhichrehabilitationwasinitiated. Phys-icaltherapywasinitiallyindicatedonlyforrangeofmotion gain;afterthiswascompleted,muscle-strengtheningphase wasinitiated,lastingaboutthreemonths.

Statisticalanalysis

Theresultsofthescoresofdifferentgroupswereanalyzedin SPSS(IBM)usingtheKruskal–Wallistest,whichissimilarin methodologytotheMann–Whitney,butallowsforthe assess-mentofmorethantwogroupssimultaneously.Surgicaltime and radiographic measurements,which were discrete vari-ables withnormaldistribution,were analyzedbyStudent’s

t-test, comparedinpairs,usingExcel.For alltests,a confi-denceintervalof95%wascalculatedandp-values<0.05were

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10 20 Male Right 5

11 23 Male Left 5

12 22 Male Right 5

GroupII

1 34 Male Left 5

2 60 Male Left 5

3 22 Male Left 5

4 32 Male Left 3

5 19 Male Right 3

6 36 Male Left 5

7 28 Male Left 3

8 32 Male Right 5

9 28 Male Left 5

10 22 Male Right 5

11 43 Male Right 3

GroupIII

1 50 Male Left 5

2 29 Male Left 5

3 37 Male Right 3

4 23 Male Right 5

5 35 Male Right 3

6 29 Male Right 3

7 27 Male Right 5

GroupIV

1 27 Male Left 3

2 20 Male Right 3

3 36 Male Left 5

4 69 Male Right 3

5 50 Male Right 5

6 59 Female Left 5

consideredtobesignificant.Thepossiblevariablesthatcould affectthefinalresultwereassessedinExcelusingPearson’s coefficient.Valuesbetween0and0.3wereconsideredtohave aweakcorrelation; between0.3and 0.6,moderate correla-tion;andgreater than0.6,strongcorrelation.Wheninverse relationshipoccurs,valuesarenegativeandwereconsidered usingthesameprinciple.

Results

Themedicalrecordsof36patientsoperatedinthisservicebya singlesurgeonfromSeptember2012toFebruary2015were ret-rospectivelyreviewed.Patientsweredividedintofourgroups accordingtothesurgicaltechniqueused:minimallyinvasive surgeryusinganchorswithouteyelet(GroupI);arthroscopy withuse ofa tightrope(GroupII); arthroscopy withuse of twotightropes(GroupIII);and,openrepairwithsubcoracoid ligationusingfourhigh-resistancewires(GroupIV)(Fig.4).

Themeanageofthepatientswas33.4years,withno signifi-cantdifferencebetweenthegroups(p=0.696).Meanfollow-up was20.2months(6–38.03).RegardingthecausesofACJD,24 (67%)occurredduetosportingaccidents, nine(25%)dueto caraccidents,andthree(8%)duetohouseholdaccidents.As fortheside,15(42%)occurredontherightand21(58%)ofthe left;thedominantsidewasaffectedin16(44%)cases.Mean preoperativedistancebetweenthecoracoidandclaviclewas 19.34mm(10.86–29.38);regardingtheclassification,23cases ofACJDVand13ACJDIII,therewasnosignificantdifference betweengroups(Table2).Meantimebetweentheinjuryand surgerywas7.57days(1–30).

Meantimeofsurgicalprocedure was31mininGroup I, 19mininGroupII,29mininGroupIII,and59mininGroup

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Fig.4–Immediatepostoperativeimage.a

a_Groups_I_,_II_,_III_,_and_IV_,_from_left_to_right,_{respectively.}

Table2–Measurementsofthedistancebetweenthecoracoidandclavicle,andquantitativeanalysisoftheACJD classification.

MeanACJDmeasurement,inmm ACJDIII ACJDV

GroupI 19.1 3 9

GroupII 19.1 4 7

GroupIII 20.2 3 4

GroupIV 17.9 3 3

p-ValuebetweenIandII 0.86 –a _–

p-ValuebetweenIandIII 0.97 – –

p-ValuebetweenIandIV 0.96 – –

a _As_this_is_a_score_presenting_non-normal_{distribution,}_it_was_not_possible_to_use_the_t_-test_to_calculate_the_p_-value.

Table3–Surgicaltimeandpre-andpostoperativemeasurementsofthecoracoclavicularspacewithlong-termlossesof thereductionachievedintheimmediatepostoperativeperiod.a

Surgicaltime inminutes

Pre-op measurement

(mm)

Immediatepost-op measurement

(mm)

Final measurement

(mm)

Immediate post-opreduction

percentageloss

Periodinwhichthe lossofreduction occurred,inweeks

GroupI 31 19.1 4.89 8.23 68% 14.5

GroupII 19 19.1 5.45 11.25 106% 12.7

GroupIII 29 20 4.96 8.17 65% 18.8

GroupIV 59 18 4.27 8.86 107% 20.2

p-Value(betweenIandII) <0.000000001 0.85 0.68 0.6 0.3 0.3

p-Value(betweenIandIII) 0.12 0.97 0.95 0.47 0.4 0.42

p-Value(betweenIandIV) 0.000002 0.96 0.93 0.24 0.2 0.09

a _Values_are_presented_as_means._The_percentage_of_loss_of_reduction_was_calculated_by_comparing_the_outcome_of_the_measurement_between

thecoracoidandclavicle,withthemeasurementobservedintheimmediatepostoperativeperiod.

lossinmillimetersonthemeasureachievedintheimmediate post-operativeperiod,wassignificantlydifferentforGroupI

inrelationshiptoGroupsIIandIV(Table3).Themomentof lossofreductionwas,onaverage,atthe13thweek,withno differencebetweengroups.

Intheclinicalevaluationatsixmonths,oneyear,andtwo yearsaftersurgery,theDASH,UCLA,VAS,andSF-36scores wereused.MeanDASHscorewas6.7points;meanUCLAwas 32.9,with17(48%)excellentresults,18(50%)good,andone regular(2%);meanVASwas1.2points,with32(91%)casesof

minorpainandthree(9%)casesofmoderatepain;andmean SF-36scorewas79.47,withnosignificantdifferencebetween groups(Tables4and5).

Somefactorsthatcouldbecorrelatedwiththefinalclinical andradiologicaloutcomewereassessed.Astrongcorrelation wasobservedbetweenthereductionachievedinthe imme-diatepostoperativeperiodandatfinalfollow-up,aswellasa moderaterelationshipbetweenthemeasurementatthetime oftheinjuryandfinal measurement(Table6).Fig.5shows the scatter plot for the measurement of the reduction in

Table4–Resultsofclinicalscores(UCLA,DASH,andVAS).a

UCLA DASH VAS

GroupI 32.4±2.5(26–35) 7.7±7.1(0.83–25) 1.2±1.3(0–4)

GroupII 33.4±2.3(27–35) 5.9±9.8(0–34) 1.2±2.0(0–7)

GroupIII 32.0±2.0(29–35) 5.8±9.0(0.83–25.83) 1.8±1.2(0–4) GroupIV 29.4±1.9(30–35) 6.5±19.1(0–47.5) 0.9±1.2(0–3)

Kruskal–Wallistest(p-value) 0.33 0.31 0.16

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Table5–SF-36score,stratifiedbyitsareas.a

Functional capacity

Limitationdueto physicalaspects

Pain Generalhealth Vitality Socialaspects Limitationsdueto emotionalaspects

Mentalhealth

GroupI 93±6.7(84–100) 76±32.3(25–100) 88±18.5(62–100) 74±18.5(55–100) 75±15.9(40–90) 85±15.3(45–100) 75±34.2(0–100) 90±8.6(80–100) GroupII 92±12.5(60–100) 75±38.2(0–100) 73±28.4(0–100) 72±19(45–100) 82±15(50–100) 92±19(37.5–100) 88±21.3(33.3–100) 78±24(33–100) GroupIII 95±9(75–100) 88±19(50–100) 73±21(41–95) 70±16(55–100) 82±12(80–100) 84±12(75–100) 88±25(33.3–100) 75±18(52–100) GroupIV 87±24(40–100) 75±38(0–100) 81±100 75±25(35–100) 92±8(80–100) 90±17(62.5–100) 74±39(0–100) 89±15(64–100)

Kruskal–Wallistest 0.9 0.91 0.23 0.78 0.13 0.33 0.8 0.23

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Table6–Correlationofvariableswiththeoutcome(Pearson’scoefficient).

Finalmeasurement VAS DASH UCLA SF36

Immediatepost-opmeasurement 0.67 0.24 0.2 −0.1 −0.5

Initialmeasurement 0.37 0.14 0.5 −0.18 −0.12

Timetosurgery 0.1 0.16 0.5 0.21 −0.8

Timetolossofreduction −0.1 0.12 0.2 −0.7 −0.12

Age 0.8 0.6 0.2 0.3 0

Association between immediate postoperative period measurement and final measurement

25 20 15 10 5 0

0 2 4 6

Immediate postoperative period measurement

Final measurement

8 10 12 14

Fig.5– Scatterplot.

theimmediatepostoperativeperiodandfinalmeasurement, showingastrongcorrelationbetweenthesemeasures.

Therewas a symptomaticlossofreduction inone(2%) casefrom GroupII,whichoccurred at14 weeks postopera-tively,requiring surgicalapproachandtreatedasachronic ACJDusingasemitendinosusgraft.Allpatientswhopracticed sportswithuseoftheupperlimb(16patients)wereableto returntothesamelevelofactivitypriortoinjury,exceptfor onepatientfromGroupII,whowasaswimmer.Therewere nosignificantcomplicationsinanyofthegroups.

Discussion

The high rate of complications associated with the vari-etyofmethodsdescribed inliteratureforthe treatmentof ACJDreflectstheinefficiencyinrestoringtheanatomyofthe acromioclavicularregion.Provisionalfixationwithpinsor cer-clageis notrecommended, dueto the increasedincidence ofdegenerativechangesoftheacromioclavicularjoint,bone erosion,andpinbreakageormigration.13_The_concept_of

trans-ferofthecoracoacromialligament(Weaver-Dunnprocedure), withitsvariousmodifications,isthatsuchatransferwould withstandtensileforces asthenative ligamentdoes. How-ever,ithasbeenproventhatthecoracoacromialligamentis biomechanicallyinferiorincomparisonwiththe reconstruc-tion with semitendinosus tendon graft, leading tochronic subluxationordislocationofthe acromioclavicularjoint in 30%ofcases.14

Treatment principle for ACJD cases is reduction of the injured joint and maintenance of this reduction until the softtissuehealsandthedistalclaviclestabilizes.Suetal.10

used an anchor in place of a screw, as a modification of the Bosworth technique, and obtained satisfactory results in11 patients operated due toACJD. They concludedthat this procedure is simple,and anatomically reproduces the coracoclavicularligamentstoprovideverticalandhorizontal stabilityincasesofACJD.Theadvantagesofusinganchors

insteadofsubcoracoidligationincludeshortersurgicaltime, whichwasalsodemonstratedinthepresentstudy,andless riskofnerveandvascularinjuries,asitisnotnecessaryto addressthemedialaspectofthecoracoid.15,16_Furthermore,

thenewgenerationofanchorswithouteyelethasthe poten-tial advantage of not having implant material, which can causebreakageofthehigh-strengthwireupontheircontact.11

Breslow et al.,17 _in _a _cadaveric _study, _compared _the

mechanicalstabilityachievedaftercoracoclavicular stabiliza-tionwiththetechniqueofsubcoracoidligaturewiththesuture anchors technique. Although the group with anchors has shownslightlybetterresults,bothmethodswere provento bestatisticallysimilar.Thesuggestedhypothesiswasthatthe ligaturehassomeaccommodationofmovementinthe sub-coracoidregion, and that it would generatelower stability. Anotherstudy,whichcomparedthebiomechanicalstrength ofEndobuttons,anchors,andhookplates,demonstratedthat thefirsttwohavebetterstabilityandresistance.18

Thelossofinitialreductionhasbeendescribedinthe liter-ature;theinaccurateinsertionsiteoftheanchorshasbeenthe reasonpointedoutbysomeauthors.9,10_The_present_authors

believethattheobservedlossismorecloselyrelatedtothe qualityofscartissue,occurringwhenthereisaruptureofthe wiresduetofatigueandthistissuehastoassumetheroleof jointstabilizer;itisimportanttonotethatthisisahypothesis, andtodatetherearenostudiesthatcorroborateit.However, this wasobservedinthe newsurgicalapproachtothe sin-glecasethatrequiredanother surgeryduetosymptomatic lossofreduction.Inthepresentstudy,weobservedthatin allcasesfromthefourgroups,therewasalossofreduction comparedtowhatwasachievedintheimmediate postopera-tiveperiod;thislossofreductionoccurred aroundthe13th week.Theauthorsalsohypothesizedthatthequalityofscar tissueisdirectlydeterminedbythestabilityachievedbythe fixationmethod,whichwasverifiedinthepresentstudy,as thesmallestlosses,inastatisticallysignificantmanner,were observedpreciselyinthemethodsthatpresentedgreater sta-bilityinbiomechanicalstudies.17,18_As_some_loss_of_reduction

isexpectedtooccur,toagreaterorlesserdegree,theauthors soughttoperformahyper-reductioninallcasesinthepresent study. A strong correlation between the immediate post-operativemeasurementandthefinalmeasurewasobserved. Thegreaterthehyper-reduction,thesmallerthefinal radio-graphic measurementofthe coracoclavicular region. Thus, the final resultwasestheticallyand radiologically satisfac-tory,withoutimpactingthefunctionalresult.Studiesinthe literatureshowthatthelossofreductiondoesnotaffectthe clinicaloutcomeofthetreatment.19–21_This_was_also_observed

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alwaysbeattempted,aimingformorefavorableradiographic andestheticresults.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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