Rev. bras. ortop. vol.52 número3

SOCIEDADE BRASILEIRA DE ORTOPEDIA E TRAUMATOLOGIA

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

Original

Article

Epidemiology

of

pelvic

ring

fractures

and

injuries

夽

Gilberto

José

Cac¸ão

Pereira,

Erick

Ribeiro

Damasceno

_,

_Daniel

_Innocenti

_Dinhane,

Francisco

Marques

Bueno,

Jaqueline

Bartelega

Rodrigues

Leite,

Bruno

da

Costa

Ancheschi

UniversidadeEstadualPaulista(Unesp),FaculdadedeMedicinadeBotucatu(FMB),DepartamentodeCirurgiaeOrtopedia,Grupode CirurgiadoQuadril,Botucatu,SP,Brazil

a

r

t

i

c

l

e

i

n

f

o

Articlehistory: Received27May2016 Accepted18July2016 Availableonline19May2017

Keywords:

Bonefractures/epidemiology Pelvicbones/injuries Epidemiologicstudies

a

b

s

t

r

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c

t

Objective:Thisstudyevaluatedthepelvicringfracturesandinjuriesinpatientsadmittedto andtreatedatthiswardbetweenAugust,2012andJanuary,2014.

Methods:66patientsweresubmittedtotreatmentprotocolsaccordingtotheirage,gender, skincolor,injurymechanism,locationofthetrauma,classificationoftheirinjuries, emer-gencyintervention,associatedinjuries,injuredsideofthebody,treatment,andmortality. Themostrelevantdatawereclassifiedaccordingtostatisticprocedures,suchasGoodman’s associationtest.MeasureswerecomparedwithStudent’st-testandanalysisofvariance associatedwithTukey’smultiplecomparisontest.

Results:Themeanagewas47years;whiteraceandmalegenderweremostcommon.Car ortruckaccidentwasthemostcommoncauseofinjuries,whichoccurredmainlyinurban sites.TypeAinjurieswerethemostfrequent.16.6%ofthecasesweresubmittedto emer-gencysurgery.42.4%displayedassociatedinjuries.Therightsideofthebodywasthemost commonlyaffectedside.Non-invasivetreatmentwasmostcommonlyused.Deathwasthe outcomein3%ofthecases,associatedtohigh-energytrauma.

Conclusions:Pelvicringfracturesandinjuriesaremoreoftenverifiedamongmales.In gen-eralandamongyoungerindividuals,trafficaccidentsarethemostcommoncauseofthe injury,whileamongtheelderly,ordinaryfallsarethemostcommonlyverifiedcause.The majorityofthoseinjuriesaresufferedinurbanareas.TypeAfracturesaremorefrequent. Themajorityofcasesdonotrequireemergencyinterventionnordotheyfeatureassociated injuries.Non-invasivetreatmentismostcommonanddeathoutcomesareassociatedto high-energytraumaswithsevereinjuries.

©2016SociedadeBrasileiradeOrtopediaeTraumatologia.PublishedbyElsevierEditora Ltda.ThisisanopenaccessarticleundertheCCBY-NC-NDlicense(http:// creativecommons.org/licenses/by-nc-nd/4.0/).

夽

StudyconductedattheUniversidadeEstadualPaulista(Unesp),FaculdadedeMedicinadeBotucatu(FMB),DepartamentodeCirurgia eOrtopedia,GrupodeCirurgiadoQuadril,Botucatu,SP,Brazil.

∗ _{Correspondingauthor.}

E-mail:erdamasceno@yahoo.com.br(E.R.Damasceno).

http://dx.doi.org/10.1016/j.rboe.2017.05.012

Estudo

epidemiológico

das

fraturas

e

lesões

do

anel

pélvico

Palavras-chave:

Fraturasósseas/epidemiologia Ossospélvicos/lesões Estudosepidemiológicos

r

e

s

u

m

o

Objetivo: Estudodasfraturas/lesõesdoanelpélvicoatendidasetratadasnesteservic¸ode agostode2012ajaneirode2014.

Métodos: Elaborou-seumprotocoloparaos66pacientes,consideraram-seosdados:idade, sexo,cor,mecanismodalesão,localdotrauma,classificac¸ãodaslesões,intervenc¸ãode urgência,lesõesassociadas,ladoacometido,tratamentoeóbito.Paraosdadosdemaior interesseforamusadososprocedimentosestatísticosqueenvolveramotestedeassociac¸ão deGoodmaneastécnicasdecomparac¸õesdemedidaspormeiodotestetdeStudenteda análisedevariânciacomplementadacomascomparac¸õesmúltiplasdeTukey.

Resultados:Aidademédiafoide47anos;pacientesdosexomasculinoebrancosforammais frequentes.Acausamaiscomumdaslesõesfoiacidentecarro/caminhãoeazonaurbana foiolocalondeelasmaisocorreram.FraturastipoAforamasmaisfrequentes.Em16,6% dospacientes,foinecessáriacirurgiadeurgênciae42,4%apresentaramlesãoassociada.O ladodireitofoimaisacometido.Otratamentoincruentofoiomaisusadoeoóbitoocorreu em3%,emcasosdetraumadealtaenergia.

Conclusões: Asfraturas/lesõesdoanelpélvicosãomaisfrequentesnosexomasculino.De modogeraleemjovens,oacidentedetrânsitoéomecanismomaisfrequente,jáemidosos équedabanal.Amaioriadaslesõesocorrenazonaurbana.FraturasdotipoAsãoasmais frequentes.Amaiorianãonecessitadeintervenc¸ãodeurgênciaenãoapresentalesões associadas.Otratamentoincruentoéomaisusadoeosóbitosestãoassociadosatrauma dealtaenergiacomgraveslesõesassociadas.

©2016SociedadeBrasileiradeOrtopediaeTraumatologia.PublicadoporElsevier EditoraLtda.Este ´eumartigoOpenAccesssobumalicenc¸aCCBY-NC-ND(http:// creativecommons.org/licenses/by-nc-nd/4.0/).

Introduction

Fracturesandinjuriesofthepelvicring,whichmayormaynot beassociatedwithseveretrauma,aregenerallynot consid-eredtobefrequent,accountingforonly2–8%ofallfractures. However,inpolytraumatizedpatientstheoccurrenceofthis typeofinjuryismuchhigher,beingobservedin20–25%of cases.1_{Fracturesofthepelvicringinyoungindividualsmost}

oftenoccurasaconsequenceofhigh-energytraumasuchas carandmotorcycleaccidentsandfallsfromgreatheights.In theelderly, they are usuallycausedbylow-energy trauma, mostcommonlyfallfrom own height,mainly dueto bone porosity.1_{Youngpatientswithpelvicringfracturesorinjuries}

due tohigh-energy trauma should beinitially assessed by amultidisciplinaryteam,because theyoftenhavemultiple injuriesandare subjecttomajorbleeding.Bleeding inthis typeofinjuryis moreseverewhen associatedwith unsta-ble pelvic fractures,which, although infrequent,present a highmortalityrateof19–31%.2–4_{Inturn,elderlypatientswith}

fracturesduetominortraumagenerallydonotpresent com-plications.Inrecentyears,aconsiderablenumberofstudies relatedtothe careand immediateor latecomplicationsof thistypeofinjuryhavebeenpublished, whichis undoubt-edlypraiseworthy,sincetheyincreasinglyinformandguide the professionals involved insuch care,characterizing the importanceandseverityoftheinjury,especiallyinpolytrauma

cases.5–9_{However,amuchsmallerproportionofpublications}

are related to epidemiological data, regional or otherwise, aboutfracturesandinjuriesofthepelvicring,whichalsohave veryimportantinformation,especiallyregardingthe charac-terizationandappropriatenessofcareforsuchaninjury.3,10,11

Therefore, this study soughtto analyze and compare vari-ousdata,suchasage,mechanismandsiteofinjury,typeof fracture,emergencyinterventions,anddefinitivetreatment, amongothers,referringtothecasesoffracturesandinjuries ofthepelvicringthatoccurredinthisregionandweretreated inthisservice.

Material

and

methods

Thestudyincluded66patientswithpelvicringfracturesand injuriestreatedatthisservicefrom August2012toJanuary 2014,whoagreedtoparticipateinthestudy.

anteriorexternalfixator(two),nointervention(three), laparo-tomy(four). Associatedinjuries:no associatedinjury(one), urethral/bladder injury(two),paraplegia (three),other frac-tures/dislocations (four), abdominal organ injuries/cranial trauma (five). Affected ring side: right (one), left (two), both (three), pubic symphysis diastasis (four). Pelvic ring fracture/injuryclassification(Tileclassification):typeA,12_type

B,typeC,andtheirsubdivisions.Definitivetreatment: non-surgical(one),iliosacralscrew(two),iliosacralscrewandplate (three),iliosacralscrewandexternalfixator(four),plates(five), platesandexternalfixator(six),externalfixator(seven). Occur-renceofdeath:no(one),yes(one).

Inthestatisticalanalysisofthepresentstudy,the associa-tionamongthevariablesofinterestwasassessedthroughthe Goodman13_{testforcontrastsamongandwithinmultinomial}

populations.When thecontingencytablepresentedalarge numberofnullcells,theresultswereonlydescriptive.Inthe caseoftheGoodmantest,resultswere presentedregarding theirsignificance(p<0.05)bylowercaseletters(comparison ofrows bycolumn) and uppercase letters (comparison of columnsbyrow).Thesedatashouldbeinterpretedasfollows: tworesponseswiththesameletter donotdifferfromeach other.

Regarding the association of age and sex, injury mech-anism, and classification of the pelvic ring fracture/injury mechanism(Tile),Student’st-testwasusedforsex,and mul-tivariateanalysisofvariancesupplementedbytheTukeytest wasusedforthevariablesinjurymechanismandpelvicring fracture/injuryclassification(Tile).

ThestudywasapprovedbytheInstitutionalReviewBoard ofthisservice(CEP4296/2012).

Results

Theresultswerepresentedinadescriptivemanner,aswell asintableswithacomparisonofsomedatathattheauthors consideredimportant.

Theageofthe individualsanalyzedrangedfrom3to86 years(meanof47).Meanageinrelationtosexwas55.3years forfemales and41.9years formales.Asforsex,therewas predominanceofmales(57.5%ofthesample).Regarding eth-nicity,thehighestpercentage(69.6%)waswhite,followedby blacks(16.6%).

The following injury mechanisms were observed:

Car/truckaccident 17(25.7%)

Motorcycleaccident 13(19.6%) Fallfromownheight 17(25.7%) Fallfromheight>1m 4(6%) Horsefall/saddletrauma 5(7.5%)

Tractoraccident 2(3%)

Beingrunover(8.8%) 8(12%)

Observation:Inthemechanismfallfromownheight,81% oftheindividualswerefemale.

Theinjurymechanismwascomparedwiththeageofthe patients(Table1).

Injuriesoccurredinthefollowingplaces:

Urbanarea 22(33.3%)

Highway 19(28.7%)

Ruralarea 8(12.1%)

Home/organization 17(25.7%)

Table2showsanassociationbetweentheplaceof occur-renceoftraumaandinjurymechanism.

Regardingtheclassificationofpelvicringfractures/injuries (Tile),thefollowingwereobserved:

TypeA(stable) 36(54.5%)

(themostfrequenttypewasA2.3,observedin61%ofcases).

TypeB(rotationally unstableandvertically stable)

19(28.7%)

TypeC(rotationallyand verticallyunstable)

11(16.6%)

Table 3 presents a comparison between the clas-sification of fractures/injuries (Tile) and age of patients.

Table 4 describes the association between

pelvic ring fracture/injury mechanism and patients’ gender.

Regardingthepresenceorabsenceofassociated (concomi-tant)injuries,thefollowingwasobserved:

Table1–Injurymechanism×age.

Injurymechanism Descriptivemeasure p-value

Mean Standarddeviation Minimum Median Maximum

1 34.3 18.4 3.0 31.0 71.0

2 30.5 16.2 14.0 22.0 60.0

3 76.6a _{7.8 59.0 79.0 86.0 p<0.001}

4 43.5 12.8 26.0 47.0 54.0

5 43.6 13.1 30.0 38.0 59.0

6 47.0 15.6 36.0 47.0 58.0

7 44.8 30.8 10.0 42.5 86.0

Table2–Placeoftrauma×injurymechanism.

Injurymechanism Place Total

Urbanarea Ruralarea Highway Home/organization

1 3(17.7) 1(5.9) 13(76.4) 0(0.0) 17

2 9(69.2) 0(0.0) 4(30.8) 0(0.0) 13

3 0(0.0) 0(0.0) 0(0.0) 17(100.0) 17

4 4(100.0) 0(0.0) 0(0.0) 0(0.0) 4

5 0(0.0) 5(100.0) 0(0.0) 0(0.0) 5

6 0(0.0) 2(100.0) 0(0.0) 0(0.0) 2

7 6(75.0) 0(0.0) 2(25.0) 0(0.0) 8

Table3–Tileclassification×age.

Classification Descriptivemeasure p-value

Mean Standarddeviation Minimum Median Maximum

A 55.6a _{27.3 3.0 65.5 86.0 p<0.01}

B 43.4 16.8 10.0 41.0 71.0

C 27.4 8.4 15.0 27.0 40.0

a _{(p<0.05)classificationAversusclassificationC.}

Table4–Injurymechanism×sex.

Sex Mechanism Total

1 2 3 4 5 6 7

F 6(22.2)aAB 5(18.5)aAB 12(44.5)bB 0(0.0)aA 0(0.0)aA 0,(00)aA 4(14.8)aAB 27

M 11(28.2)aA 8(20.5)aA 5(12.8)aA 4(10.3)aA 5(12.8)aA 2(5.1)aA 4(10.3)aA 39

Table5–Associatedinjuries×sex.

Sex Associatedinjuries Total

1 2 3 4 5

F 16(59.3)aB 1(3.7)aA 0(0.0)aA 10(37.0)aB 0(0.0)aA 27

M 22(56.5)aB 2(5.1)aA 2(5.1)aA 11(28.2)aAB 2(5.1)aA 39

Noassociatedinjury 38(57.5%) Associatedinjury 28(42.4%)

Observation: Fractures/dislocations (single or multiple) werethemostfrequentlyassociatedinjuries,presentin75% ofthecaseswithassociatedinjuries.

Theotherassociatedinjuriesobservedwerethoseofthe urethra/bladder,abdominalorgans,andcranialtrauma.

Table5presentstheassociationbetweenthepresenceor absenceofassociated(concomitant)injurytothepelvicring injuryandthepatients’sex.

Regardingtheneedforemergencyintervention,the follow-ingwasobserved:

Noemergencyintervention 55(83.3%) Emergencyintervention 11(16.6%)

Typeofintervention:

- Anteriorexternalfixator–six. - C-clamp–five.

- Laparotomy(associatedwithclamp)–one.

Table6–Urgencyinterventionstatus(typeof fixation)×injurymechanism.

Mechanism Interventions Total

Clamp Fixator No

1 2(11.8)aA 4(23.5)aAB 11(64.7)bB 17

2 0(0.0)aA 2(15.4)aA 11(84.6)bB 13

3 0(0.0)aA 0(0.0)aA 17(100.0)bB 17

4 1(25.0)aAB 0(0.0)aA 3(75.0)bB 4

5 0(0.0)aA 0(0.0)aA 5(100.0)bB 5

6 2(100.0)bB 0(0.0)aA 0(0.0)aA 2

7 0(0.0)aA 0(0.0)aA 8(100.0)bB 8

- Reductionofhipdislocation(associatedwithringfixator)– one.

- Linearexternalfixator(associatedwithringclamp/fixator) –three.

- Bladder/urethraintervention(associatedwithringfixator)– two.

Table7–Classificationoftheinjury×trauma mechanism.

Mechanism Classification Total

A B C

1 7(41.2)aA 5(29.4)abA 5(29.4)aA 17

2 6(46.2)aA 4(30.8)abA 3(23.0)aA 13

3 17(100.0)bB 0(0.0)aA 0(0.0)aA 17

4 1(25.0)aAB 3(75.0)bB 0(0.0)aA 4

5 1(20.0)aAB 4(80.0)bB 0(0.0)aA 5

6 0(0.0)aA 1(50.0)abA 1(50.0)aA 2

7 4(50.0)abA 2(25.0)abA 2(25.0)aA 8

Table7showstherelationshipbetweenthepelvicring frac-tures/injuriesclassification(Tile)andtraumamechanism.

Table8presents acomparisonbetween themechanism ofpelvicringfractures/injuries withpresenceorabsenceof associatedinjury.

Regardingsideoftheringthatwasaffected(local),the fol-lowingwasobserved:

Right 30(45.4%)

Left 23(34.8%)

Both 9(13.6%)

Pubicsymphysisdiastasis 4(6%)

Table9showsanassociationbetweenaffected sideand injurymechanism.

Regarding definitive treatment, the following was observed:

Non-surgical 42(63.6%)

Surgical 24(36.4%)

Materialsused

- Plate(publicsymphysis/iliosacral)–13. - Iliosacralscrew+plate(pubicsymphysis)–five. - Iliosacralscrew–three.

- Anteriorexternalfixator–two. - Anteriorexternalfixator+plate–one.

Regardingtheoccurrenceornotofdeath,thefollowingwas observed:

No 64(96.9%)

Yes 2(3%)

Observation: Deaths occurred in cases of high-energy trauma(trafficaccident)withtypeBorCpelvicringinjuries, inadditiontosevereassociatedinjuries.

Discussion

The data on age (mean 41.9 years), sex (more frequently males),andethnicity(predominantlywhites)observedinthe presentsample,ingeneral,wereveryclosetothosepresented intheliterature.Kobbeetal.14_{reportedameanageof47.3}

yearsintheircasesofpelvicringinjury.JezekandDzupa,15_in

anepidemiologicalstudyonageandmechanismofpelvicring

injury,reportedaslightlyhighermeanage(51years); strati-fiedbysex,meanageoffemalepatientswas53whilemale patientswas49.Gansslenetal.,3_{inasimilarepidemiological}

study,alsoreportedahigherincidenceofpelvicringinjuries inmales,inaproportion(56.7%)veryclosetothatobservedin thepresentsample(57.5%).Chueireetal.,9_inan

epidemiolog-icalstudy,reportedalargernumberofmaleswithringinjuries (67%); white subjects alsorepresented a higherpercentage oftheirsample.Onlythemeanageoftheircases(37years) waslowerthanthatobservedinthepresentstudy.Devarinos etal.11_{reportedtheirexperienceinpelvicringinjuriesin}

Ire-land,havingalsoobservedamuchhigherpercentageofmales (76%),withameanageof36.5years.

Itwasobservedthat,generallyspeaking,theliteraturealso presentsahigherincidenceofmalesexinthistypeoftrauma, exceptinspecificcases,asreportedbyAlnaibet al.,16 _who

assessedonlypelvicringinjuriesduetolow-energytrauma (osteoporoticbones)andfoundahigherincidenceinfemales. In relationshiptomean age, the authorsconsider that the valueobservedinthepresentstudywasslightlyhigherthan thoseobservedinsomeotherstudies,asthepresentsample includednumerouselderlyindividuals.

Regarding themechanismofthepelvicringinjuries,we observedthat,ingeneral,accidentsinvolvingtransportation vehicles(cars/trucksandmotorcycles)werethemostfrequent causes ofinjuries,accounting for45.3%ofthe total. When includingthemechanism“beingrunover”(alsocausedbythe sametypeofvehicle),totalofinjuriescausedbytraffic acci-dentswas57.5%,whichreinforcesthefactthattheseinjuries werecaused,forthemostpart,bymotorvehicles.Devarinos etal.,11 _{inalongfollow-upofpelvicringinjuries(10years),}

indicatedthatthemostfrequentinjurymechanismwastraffic accidents(74%).Freitasetal.,10_{inaliteraturereviewof}

stud-iesonpelvicringfracturesinrecentdecades,observedthat themostprevalenttraumamechanismswerethoserelatedto traffic.Chueireetal.9 _{reportedavery similarpercentageto}

thatobservedinthepresentstudy;intheirstudy,pelvicring injurieswerecausedbycaraccidentsin23%ofcases(25.7%in thepresentstudy)andbymotorcycleaccidentsin19%(19.6% inthepresentstudy).

In thecomparisonofthemechanism ofinjury withthe age ofthepatients, anexpectedbut importantfinding was observed:thesignificantpredominanceoftheelderlyincases in whichthe injury was causedby afallfrom ownheight (mechanism 3).Furthermore,itwas alsoobservedthat the maintraumamechanisminadolescentsoryoungadultswas trafficaccidents(mechanisms1and2),withindividualsinside thevehicle.JezekandDzupa,15_{intheirstudyontheinfluence}

ofageonthemechanismofringfractures,reportedthat com-monfallwasthemostfrequentcauseofthistypeofinjury intheelderlyand,ofthose,femaleswerethemostaffected, aresultsimilartothatobservedinthepresentstudy,Those authorsalsonotedthatmenweresignificantlymoreinvolved infracturesresultingfrommotorcycleaccidentsandfallsfrom stairs.Krappinger et al.,4 _{in theirstudy onpelvic fractures}

Table8–Injurymechanism×associatedinjury.

Mechanism Associatedinjury,n(%) Total

1 2 3 4 5

1 9(52.9) 0(0.0) 2(11.8) 6(35.3) 0(0.0) 17

2 5(38.4) 2(15.4) 0(0.0) 6(46.2) 0(0.0) 13

3 13(76.5) 0(0.0) 0(0.0) 4(23.5) 0(0.0) 17

4 3(75.0) 1(25.0) 0(0.0) 0(0.0) 0(0.0) 4

5 5(100.0) 0(0.0) 0(0.0) 0(0.0) 0(0.0) 5

6 0(0.0) 0(0.0) 0(0.0) 1(50.0) 1(50.0) 2

7 3(37.5) 0(0.0) 0(0.0) 4(50.0) 1(12.5) 8

Table9–Affectedside×injurymechanism.

Mechanism Affectedside Total

1 2 3 4

1 5(29.4) 8(47.1) 4(23.5) 0(0.0) 17

2 4(30.8) 4(30.8) 3(23.0) 2(15.4) 13

3 11(64.7) 6(35.3) 0(0.0) 0(0.0) 17

4 2(50.0) 1(25.0) 0(0.0) 1(25.0) 4

5 1(20.0) 0(0.0) 0(0.0) 4(80.0) 5

6 1(50.0) 0(0.0) 1(50.0) 0(0.0) 2

7 4(50.0) 2(25.0) 1(12.5) 1(12.5) 8

fracturesduetocommontraumasincreaseswithage;the inci-denceinthegeneralpopulationis2–37/100,000individuals, increasingto92/100,000inindividualsagedover60yearsand to446/100,000inthoseagedover85years.Baloghetal.,17_inan

epidemiologicalstudyonthesametypeofinjury,reportedthat low-energytraumafracturemechanismwasfallfromheight oflessthan1minallcases.

Aspreviouslymentioned,arelationshipbetween adoles-cents/youngadultsandtrafficaccidentswasalsoobservedin thepresentstudy(Table1).Freitasetal.,10_{inananalysisof}

theliteratureonthesubject,commentedthattrafficaccidents aregenerallyamongthemostfrequentcausesandpresenta higherriskintheyoungmalepopulation.Devarinosetal.11

alsomentionedtrafficaccidentsinpelvicringinjuries;intheir work,thetypicalpatientwasmaleandagedaround30years. In relationship to the place where the injuries of the pelvicringoccurred,theurbanzonewasthemostfrequent placeinthe present study.In the comparisonoftheplace ofoccurrencewiththeinjurymechanism(Table2), motorcy-cleaccidents(mechanism2)intheurbanareastoodout.The sameTablealsoindicatesthatmechanisms5and6,accidents withanimals(horses)andtractors,standoutintheruralarea, car/truckandmotorcycleaccidents(mechanisms1and2)on thehighway;athomes/institutions,100%ofthecaseswereof fallfromownheight(mechanism3).Theauthorsbelievethat theseresultsarecompatiblewithtypeoftraumaandplace ofoccurrence. Nonetheless, no references in the literature regardingtheseparameterswereretrieved.

Regarding the classification of pelvic ring injuries, the authors emphasize that in the present study, of all frac-tures/injuries, type A (stable) was the most frequent and, amongthese,subtypeA2.3 (isolatedfractureoftheanterior

region of the ring – one or four branches) was the most

common.ThesewerefollowedbytypesB(rotationally unsta-ble and vertically stable) and C (rotationallyand vertically unstable). Table3(classificationbyage)presentsa predom-inanceoftypeA(stable)fracturesintheelderlyandoftype C(rotationallyandverticallyunstable)inyoungerindividuals, i.e.,thelatterhadthemostsevereinjuries.Grotzetal.18_also

associatedtheseverityofringinjurieswithageandreported thatthemostseriousinjuries(includingboneexposure) usu-allyaffectyoungadultmalesasaresultoftrafficaccidents. Gansslen et al.,3 _{in epidemiological study on pelvic ring}

injurieswithalargesample,alsofoundthattypeAfractures (stable)werethemostfrequent,accountingfor54.8%ofthe cases(includinghigherinvolvementoftheischiopubicbones). Moreover,intheirstudytheorderwassimilartothatobserved inthepresentstudy:typeB(rotationallyunstableand verti-callystable)wasthesecondmostcommon,followedbytypeC (rotationallyandverticallyunstable).Chueireetal.9_reported

that type A injuries were the most common,occurring in 55%ofthesample,andwerealsorelatedtotheelderly,with involvementofischiopubicbranches;inthatstudy,the sub-typeA2.2wasthemostcommon.Thoseauthorsalsoobserved

typeB(30%)asthesecondmostcommon,followedbytype C(15%).Itwasobservedthatregardingtheorderandthe fre-quencyoffracturetypes,aswellaspercentageandtheplace ofinvolvement,theresultswereveryclosetothoseobserved inthepresentstudy.Freitasetal.,10_{inaliteraturereviewfrom}

indexeddatabases,soughttoanalyzetheevolutionofpelvic ringfracturesinthepastdecades;theseauthorsalsoobserved typeAasthemostfrequent,followedbytypesBandC.

offemales.Thus,inmales,thedistributionofmechanismof injurywashomogeneous,whereasinfemales,fallfromown heightwasnoteworthy.JazekandDzupa15_{commentedonthe}

mechanismofpelvicringinjuriesandalsoreportedthat frac-turesduetosimpletraumaweresignificantlymorecommon inolderwomen;thewomeninthisagegroupwereeightyears olderthanthemen.Alnaibetal.,16_{inastudyonpelvicring}

fractures inthe elderly caused by-low energytrauma, also reportedamuchhigherpercentageofinvolvementinfemales, 80.4%ofthecases.

Regarding the presence of injuries/fractures associated withpelvicringinjuries,theliteraturepresentsacertain vari-ation.Chueireet al.9_{reported ahigher percentageofcases}

ofotherinjuriesassociatedwithpelvicringfracturesthanof isolatedfractures;54%oftheircasesshowedsometype asso-ciatedinvolvement.Regardingthetypeofconcomitantinjury, theauthorsalsoobserved,asinthepresentstudy,a preva-lenceoffractures/dislocations inother places. Richardand Tornetta,19_{inastudyontheemergencytreatmentonpelvic}

injuriesringwiththeC-clamp,reportedthat37.5%ofcases had other fractures associated with the pelvic ring injury. Sagietal.,20 _{inastudyofseriousinjuriesofthepelvicring}

(verticalinstability),observedconcomitantinjuriesin36.2% ofpatientsandfoundbladderruptureasthemostcommon injuryassociatedwiththistypeofringinjury.Inthepresent study,bladderinjurywasmuchlessfrequent,butitis notewor-thythatalltypesofringfractures/injurieswereincluded,not onlythemoreseverecases.Inturn,Gansslenetal.,3_inan

epi-demiologicalstudywithalargesampleofpelvicringinjuries includingalltypes,observedthatmosthadsomekindof asso-ciatedinjury;only30.2%ofthecaseswereisolatedinjuries.In thepresentstudy,injuriesassociatedwiththoseofthepelvic ring,althoughoccurringinaconsiderablepercentage(42.44% –Table9),werenotashighasthoseobservedinthe litera-ture.Theauthorsbelievethattheconsiderablenumberofless severefractures(TypeA)inthissampleandthelesser involve-mentofotherareasororganshasinfluencedthefindingthat the general percentage ofassociated injuries was not ele-vated.Alsoinrelationtoassociatedinjuries,genderofpatients (Table5)were comparedin orderto assess apossible pre-dominance.However,nosignificantcorrelationwasobserved. Regarding the needforemergency interventioninpatients whosufferedpelvicringfracture/injury,itwasobservedthat inthegreatmajority(83.3%)ofcasestherewasnoneedfor urgentintervention.Incaseswheretheseinterventionswere made,orthopedicinterventionswerethemostfrequent,with abalancebetweentheuseofC-clampandanteriorexternal fixator.Theotheremergencyinterventionswererecordedand numbered,butnotconsideredseparately,sincetheywere per-formed(concomitantly)inthesamepatientswhounderwent orthopedicinterventions.Chueireet al.9 _reportedan

emer-gencyinterventionrate of32% intheircasesofpelvicring fractures;orthopedicinterventionsandlaparotomywerethe mostfrequent,buttheauthorsdidnotspecifywhetherthe procedures were done separately or in the same patients. Baloghetal.,17 _{inanepidemiologicalstudy ofringinjuries,}

indicatedthat15%ofthecasesofhigh-energytraumarequired emergencyringfixation.Inturn,Pisanisetal.,1 _assessinga

large sample of patients with pelvic ring injuries to com-parethestabilizingringmethodsintheemergencytreatment,

indicated that only3.4%ofpatients underwent emergency orthopedicprocedures;ofthese,theC-clampwasoneofthe mostoftenused.

Table 6compares the need for emergency intervention withthemechanismoftheinjury; asignificant association was observed, notably between the mechanisms car/truck and motorcycle accidents, together with tractor accidents (high-energytrauma)and needforemergencyintervention, especially with the anterior external fixator and C-clamp. Pisanis et al.1 _{alsoreported thatthe pelvicring injuriesin}

theirsamplethatrequiredurgentinterventionfor stabiliza-tionresultedfromhigh-energytrauma,andthattheC-clamp wasthemostusedmethod.Abrassartetal.,21_inastudyon

emergency treatment inunstable pelvic ring injuries asso-ciatedwithhemodynamicinstability,reportedthatallcases werehigh-energytrauma,suchasmotorvehicleaccidentsor fallsfromgreatheights.Theauthorsemphasizethat,ofthese, thevastmajority(80%)requiredringfixationwithexternal fix-atororC-clamp.Brumetal.,22_{inastudyonseriousinjuries}

to the pelvic ring that included onlypolytrauma patients, reportedthatemergencyringfixation,whetherwithC-clamp oranothermethod,wasnecessaryin35%ofthesample.Grotz etal.,18_{inastudyonthetreatmentofopenfracturesofthe}

ring,didnotdiscusspercentages,butreportedthatincases requiringemergencyinterventiontostabilizethering,theuse ofC-clamporanteriorexternalfixatorisrecommended.

Mechanismoftraumawascomparedwiththe classifica-tionoftheinjuries(Table7).WeobservedthatintypeA(stable fracture) injuries, the mechanism of fall from own height, i.e.,alow-energytrauma,isnoteworthy;intypeB(rotational instabilityandverticalstability),themostprevalent mecha-nismswerefallfrommorethan1mandhorseaccident,which are consideredmoderateorhigh-energytraumas. IntypeC (rotationalandverticalinstability)therewasapredominance ofcar/truckandmotorcycleaccidents,i.e.,onlyhigh-energy traumas. Krappinger et al.4 _{examined cases of pelvic ring}

fracturesinosteoporoticbonesandreportedthatthetypical fracturesofthissegmentarestableandthatthemechanism ofinjuryistrivialtrauma,suchasfallfromownheight.Loon et al.,23 _{ina study on the treatment of typeB pelvic ring}

injuries,observedthatthemostcommonmechanisminthis typeofinjurywasfallingfromaheightgreaterthanordinary, aswellastrafficaccidents;JezekandDzupa,15_inastudyon

themechanismofringfracture/injuryandtheageofpatients, reported that simplefractures (AO typeA)are common in elderly individualsand those consideredmoresevere (type C)arepredominantinyoungmales.Theauthorsalsopoint outthatthemostseriousfracturesarerelatedtohigh-energy traumas,withsignificantinvolvementofmotorcycleaccidents andfallsfromgreatheights.Baloghetal.17_{observedthatTile}

typeBandCfracturesresultedfromhigh-energytraumawith apredominanceofaccidentswithcarsandmotorcycles.

accidentsandmotorcyclesitems1and2–mechanism)were noteworthy.Baloghet al.,17 _{inanepidemiologicalstudy on}

pelvic ring injuries, compared the injuries caused by low-andhigh-energytrauma,havingalsoreportedamuchhigher andmoresevereincidenceofconcomitantinjuriesincasesof high-energytrauma.

We observed that the right side of the ring was the mostaffected,but noelements tojustifythis finding were found.Comparingthemechanismofinjurywithaffectedside (Table9),weobservedthatontherightside(item1)the mech-anismfallfromownheight(item3–mechanism)wasmore prevalent.Onthe leftside(item2) andonbothsides(item 3),car/truckandmotorcycle accidentmechanisms(items1 and2 –mechanism)stood out.Inthe casesofpubic sym-physisdiastasis(item4–affectedside),themainmechanism was horse accident (fallor trauma in the saddle – item 5 ofthe mechanism). Inrelation to these parameters, pubic symphysis diastasis was only associatedwith the mecha-nismof injury “direct trauma inthe saddle ofthe horse.” Itwasnotpossibletoassociateinjurysidewithmechanism oftrauma;furthermore,noreferencesintheliteraturewere retrieved.

Regarding the definitive treatment used, most of the present cases (63.6%) underwent non-surgical treatment. Gansslenetal.,3_{inastudyofpelvicringinjuries,alsoreported}

ahighpercentageofcases(78%)treatednon-surgically.Inthe presentstudy,theauthorsbelievethatthehighpercentageof typeAfractures(54.5%)inthesampleinfluencedthisresult, sincethesearestableinjuriesandalmostallare treatedin anon-invasivemanner.Amongthecasessubmittedto surgi-caltreatment,theplate(pubicsymphisis/iliosacral)wasthe mostused materialinthe present study (isolated or asso-ciated),followed byiliosacralscrew(isolatedorassociated). DimitriouandGiannoudis24_{alsohighlightedtheuseofplate}

inthe pubic symphysisassociated withiliosacral screwor iliosacralfixation with plates (anterioror posterior). These authorsalsocommentedontherecenttrendofincreaseduse ofpercutaneousfixationwithiliosacralscrewincasesofring injury.

Regardingthetypeoffixationusedinthepresentstudy, internal fixation was much more frequent (87.5%); exter-nalfixation(singleorassociated) accountedforonly12.5% of the cases. Chueire et al.,9 _{in their series of pelvic ring}

injuries,presentedaslightlysmallerpercentageofpatients whounderwentsurgicaltreatment(29%)whencomparedwith the present study; however, the type offixation used was quitedifferent,asthoseauthorsusedexternalfixationin75% oftheir cases and internal fixation in25%. In the present study,iliosacralfixation(isolatedorassociated)wasused.The authors believethat thereis atrend ofgreater use ofthis methodinthisservice,sinceitisconsideredefficientinthe reductionandstabilizationoftheiliosacraljoint,aswell as lessinvasive.Tosounidisetal.,25_{assessingdatafromGerman}

centersoftreatmentofpelvicringinjuries,alsoreportedan increasetendencyofiliosacralscrewuseinthetreatmentof thistypeoftrauma.Strobl etal.,26_{inarecentstudyonthe}

treatmentofunstableinjuriesoftheposteriorregionofthe pelvicring,reportedthatinmanycenterstheiliosacralscrew isalreadyestablishedasthemostusedtreatmentinposterior fixationofthering.Inturn,TrikhaandGupta27_reporttheuse

ofiliosacralscrewinpelvicinjuries,butalsorecommend tran-siliacplatesintheposteriorregionofthering.Mulleretal.,28

inastudyonunstableringinjuries(typeC)recommenda com-bination oftypesofsyntheses,i.e.,anterior internalfixator (subcutaneous)andposteriorstabilization(iliosacralscrewor spinopelvicandiliolumbarsupport);theseauthorsremarked uponthewidevarietyoftechnicaloptionsforfixationinring injuries.Itwasobservedthatalthoughthereisatendencyin theliteratureforlessinvasiveinternalfixations,avarietyof ringosteosynthesismaterialsarestilladvocated.

Inrelationtomortalityinpelvicringinjuries,the litera-turepresents indexeswithwide variation,andthe authors always emphasizethe association oftheserates with con-comitantinjuriesandtheseverityoftheringinjuryitself.1,29,30

Inthepresent study,thisassociation wasalsoobserved,as thecasesofdeathwereringinjuriestypesBorCwithsevere associated injuries. Gansslenet al.,3 _{inan epidemiological}

study on this typeof injury, reported an overall mortality rateof13.4%,butindicatedthatthisratewasdirectly asso-ciated with extrapelvic trauma. Mortality observed in the literature17,21,22,29,30 _{ranges from 2% to 46%, and the}

per-centageisalways dependentonseverity ofthe ring injury, on whether trauma was ofhigh energy, and on the pres-ence ofassociated injuries.Pohlemann et al.,29 _{in astudy}

onpredictors ofmortalityinringinjuries,commentedthat in recent years the rate stillremains high when consider-ingonlycasesofcomplexinjuriesofthering,butwhenall typesofringfractures/injuriesareincluded,ageneraltrend towarda decreaseinthe mortalityrateisobserved(5%,in thesecases).Thefactisattributedtotheinclusionofless seri-ousinjuriesandimprovedtreatmentbothinthepre-hospital phaseandintheemergencycare.Chueireetal.,9_intheirstudy

ofpelvicring fractures,reported a7%mortalityrate; these authorsalsohighlightedthesignificantrelationshipwiththis extrapelvic trauma. Richard and Tornetta,19 _{in a study on}

serious injuriesofthepelvicring,reportedamortalityrate of6.8%.

Theauthorsconsideredthatthemostimportantfactorin thelowmortalityrateobservedinthepresentstudy(3%)was thehighnumber oftypeAcases,whichareusually associ-ated withlow-energy traumas and donot haveassociated injuriesorcomplications.Furthermore,thesmallpercentage ofseveretypeCinjuries(16.6%)alsoinfluencedthisrate,as theseareduetomuchmoreseveretrauma.Theauthors high-lightthatthetwocasesofdeathinthepresentstudywere unstable injuries and had serious and multipleassociated lesions.Inadditiontothesefactors,itisalsonoteworthythat inrecentyearstherehasbeenanimprovementintheoverall careforpolytraumapatientsinthisservice,aswellasgreater trainingandexperienceoftheorthopedicstaff,bothin emer-gencyproceduresandinthedefinitivetreatmentofpelvicring injuries; the authors believethat these elementsalso con-tributed to the low mortality rate observed inthe present work.

Conclusions

- Theyaremorefrequentinmales.

- In general, mostcommon mechanism ofinjury istraffic accident.

- In theelderly,the mostcommon mechanismofinjuryis low-energytrauma(fallfromownheight),thereisa preva-lence ofthe female sex,and the mostcommonplace of injuryisathome/institution.

- Inadolescents/youngadults,themostcommonmechanism ofinjury ishigh-energytrauma(traffic accident)andthe mostcommonplaceofinjuryistheurbanareaandhighway. - Ingeneral,typeAfracturesarethemostfrequent,followed

bytypesBandC.

- TypeAfracturesarethemostcommonintheelderlyand typeC,inadolescents/youngadults.

- Most injuries do not need emergency intervention and, whennecessary,orthopedicinterventionsarethemost fre-quent.

- Emergency interventionsareassociatedwithhigh-energy trauma.

- Amongassociatedinjuries,fractures/dislocationsinother sitesarethemostcommonandareassociatedwith high-energytrauma.

- Non-surgical treatment is the most common; in cases treatedsurgically,externalfixationisthemostusedmethod. - Deaths occur inunstable fractures andsevere associated

injuries.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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