Rev. bras. ortop. vol.52 suppl.1

SOCIEDADE BRASILEIRA DE ORTOPEDIA E TRAUMATOLOGIA

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

Original

article

Open

versus

arthroscopic

approach

in

the

treatment

of

femoroacetabular

impingement:

a

case–control

study

with

two-years

follow

up

夽

Bruno

Dutra

Roos

,

Milton

Valdomiro

Roos

,

Antero

Camisa

Júnior

,

Ezequiel

Moreno

Ungaretti

Lima

_,

_Maurício

_Domingos

_Betto

a_{HospitalOrtopédicodePassoFundo,DepartamentodeOrtopediaeTraumatologia,PassoFundo,RS,Brazil}

b_{HospitalOrtopédicodePassoFundo,GrupodeCirurgiadoQuadril,PassoFundo,RS,Brazil}

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Articlehistory:

Received1December2016 Accepted26January2017 Availableonline9August2017

Keywords: Hipjoint

Femoroacetabularimpingement Hipinjuries

Osteoarthritis

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b

s

t

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t

Objective:To compareclinical andimagingresults andcomplications betweenpatients treated for femoroacetabular impingement (FAI) who underwent either anterior open surgeryoranarthroscopicapproach,withaminimumfollow-upoftwoyears.

Methods:Thisretrospectivecase–controlstudyincludedpatientssubmittedtoFAIsurgical treatment betweenNovember2007andMarch 2012.Patientstreated withopensurgery werecomparedwiththosetreatedwitharthroscopy.Patientswereclinicallyassessedby themodifiedHarrisHipScore,Non-ArthriticHipScore,andinternalhiprotation.Patients wereradiographicallyassessedbythecenter-edgeangle,jointspacewidth,alphaangle, neck-headindex,degreeofarthrosis,andpresenceofheterotopicossificationofthehip. Results:Inthestudyperiod, 56patients(58hips)withFAIwereincluded;16underwent opensurgeryand40underwentarthroscopy.The40patientstreatedbythearthroscopic routehadameanfollow-upof29.1months,and75.6%presentedgoodorexcellentclinical results.Theradiographicevaluationparametersprogressedtonormallevels.The16patients whounderwentopensurgeryhadameanfollow-upof52months,and70.58%presented goodorexcellentclinicalresults.Theradiographicevaluationparametersprogressedto normallevels.Postoperativeclinicalandradiographicresultswereconsideredsimilarin bothgroups.

Conclusions: ArthroscopyandopensurgerytreatmentsforFAIprovidedcomparableclinical andradiographicresults.However,ahigherrateofcomplicationswasobservedintheopen surgerygroup.

©2017PublishedbyElsevierEditoraLtda.onbehalfofSociedadeBrasileiradeOrtopedia eTraumatologia.ThisisanopenaccessarticleundertheCCBY-NC-NDlicense(http:// creativecommons.org/licenses/by-nc-nd/4.0/).

夽

StudyconductedatHospitalOrtopédicodePassoFundo,CentrodeEstudosOrtopédicos,PassoFundo,RS,Brazil. ∗ _{Correspondingauthor.}

E-mail:brunodroos@gmail.com(B.D.Roos).

http://dx.doi.org/10.1016/j.rboe.2017.07.007

Abordagem

anterior

aberta

versus

artroscópica

no

tratamento

do

impacto

femoroacetabular:

estudo

caso-controle

com

seguimento

mínimo

de

dois

anos

Palavras-chave: Articulac¸ãodoquadril Impactofemuroacetabular Lesõesdoquadril Osteoartrite

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Objetivos: Compararos resultados clínicose radiográficos,bemcomo as complicac¸ões observadasempacientessubmetidosaotratamentocirúrgico,devidoaimpacto femoroac-etabular,sobabordagemartroscópicaouanterioraberta,comseguimentomínimodedois anos.

Métodos: Estudocaso-controleretrospectivo,compacientesoperadosentrenovembrode 2007emarc¸ode2012equeforamsubmetidosatratamentocirúrgicodeimpacto femoroac-etabular. Pacientes submetidos à abordagem abertaforam comparados compacientes submetidosàabordagemartroscópica.Ospacientesforamavaliadosclinicamentepelos escores clínicosHarris Hipmodificado, NonArthriticHipe quanto à rotac¸ãointerna do quadril.Ospacientesforamavaliadosradiograficamente,aferiram-seoângulocentro-borda, adimensãodoespac¸oarticular,oânguloalfa,oíndicecolo-cabec¸a,ograudeartroseea presenc¸adeossificac¸ãoheterotópicadoquadril.

Resultados: Foramincluídosnoestudo56pacientes,16submetidosàabordagemabertae 40àartroscópica.Os40pacientestratadosporviaartroscópicaforamseguidospor,em média,29,1meses,75,6%apresentaramresultados clínicosbonsouexcelentes.Quanto àavaliac¸ãoradiográfica,observou-secorrec¸ãoparaíndicesconsideradosnormais.Os16 pacientes operados por via aberta obtiveram seguimento médiode 52 meses, 70,58% apresentaram resultados clínicos bons ou excelentes. Quanto à avaliac¸ão radiográfica, observou-secorrec¸ãoparaíndicesconsideradosnormais.Osresultadosclínicose radio-gráficospós-operatóriosforamconsideradossemelhantesemambososgrupos.

Conclusão: Osresultadosclínicoseradiográficosdotratamentoartroscópicodoimpacto femoroacetabularforamcomparáveisaosresultadosdotratamentoaberto.Observamos ummaiornúmerodecomplicac¸õesnogrupoaberto.

©2017PublicadoporElsevierEditoraLtda.emnomedeSociedadeBrasileirade OrtopediaeTraumatologia.Este ´eumartigoOpenAccesssobumalicenc¸aCCBY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Introduction

Femoroacetabularimpingement(FAI)isnowrecognizedasa commoncauseofhippainintheyoungpopulation,with pos-sibledegenerativeconsequences.1,2 _{Boththeknownimpact} mechanisms (cam or inclusion, and pincer or impaction) are associated with pain, restricted range of motion, and decreasedexercisetolerance.3_{Currently,severalstudieshave} suggestedthatsomecasesthatwerepreviouslyconsideredas idiopathichiposteoarthritisaresecondarytoFAI.4–8

Conservativetreatmentcanbeattemptedinitially;it con-sists ofmodifying high-impactphysical activities,avoiding weightedexercisesassociatedwithexcessiveflexionand tor-sionmovementsthatincreasejointdemand,and,finally,the useofanti-inflammatorymedications.Surgicaltreatmentis indicatedincaseswhenconservativetreatmentbringsonly temporary relief.9,10 _{Some authors claimthat, sinceit is a} mechanicalcondition,delayingsurgicaltreatmentoftheFAI maynotbebeneficialtothepatient.However,thereisstillno consensusintheliteratureregardingthissubject.1,2,10,11

Surgical treatment options for FAI include open sur-gical correction with posterior hip dislocation (Ganz approach), anterior hip approaches (Smith-Petersen, Hueter,Sommerville,andanteriorextensible,amongothers),

videoarthroscopicsurgery,andacombinationofarthroscopic techniqueandanteriormini-incision.1–9

Thepresentstudyaimedtocomparetheclinicaland radio-graphicresultsandthecomplicationsrelatedtopatientswho underwent surgical treatmentofFAIperformed bytheHip Surgery Groupof this institutionusing the arthroscopic or anterior open (iliofemoral) approach,witha minimumtwo yearfollow-up.

Material

and

methods

Accordingtotheestablishedcriteria,56patients(58hips) metall the necessaryrequirements forthis study.Patients were divided into two groups: GroupI _{included casesthat} underwent arthroscopic surgery, and Group II, those that underwentopenapproach.

GroupI_{(arthroscopictreatment)included40patients;36} (87%)weremale,andthemeanagewas36.12years(SD=8.7, range:21–47years).Therighthipwasoperatedonin20cases (48.78%),andthelefthip,in21(51.21%);onecasewasoperated bilaterallyatdifferenttimes.

GroupII_{(openapproach)included16patients;11(68.75%)} weremale,andthemeanagewas35.76years(SD=9.5,range: 19–47years). Therighthip wasoperated onin eightcases (47.05%),andtheleft,innine(52.94%);onecasewasoperated bilaterallyatdifferenttimes.

Regardingtheclinicalaspects,patientswereassessed pre-andpostoperativelythroughtheHarrisHipScore,modifiedby ByrdapudGuimarães13_{(MHHS);theNon-ArthriticHipScore}14 (NAHS);andtherangeofinternalrotation(IR)oftheaffected hip(withgoniometerforgauging).

According to the Harris Hip Score modified by Byrd,13 resultswerestratifiedaspoor(MHHS<70points),fair(70–79 MHHS),good(MHHS80–89),orexcellent(MHHS90–100).10

All patientswere assessedbyradiographs (anteroposte-rior [AP] view ofthe hip in the orthostatic position, Dunn 45◦_{, Dunn 90}◦_{, and Lequesne’s false profile),}15 _{as well as} magneticresonance imaging forthe diagnosis ofchondral and labralinjuries.Pincer-type FAIwas diagnosedby mea-suring the angle of femoral head coverage and acetabular version on AP radiographs of the hip in the orthostatic positionand in Lequesne’sfalse profile.Cam-typeFAIwas defined as alpha angle greater than 50◦ _{in Dunn 45}◦ radiographs.16

Inthepreoperativeperiod,thefollowingweremeasured: Tönnis17_{hiparthrosisclassification;center-edgeangle(}␪_CE); sizeofthesmallestjointspace,inmillimeters,onAP radio-graphsofthehipintheorthostaticposition;alphaangle,as describedbyMeyer16_inDunn45◦ _radiographs(␪␣_);and lat-eralviewhead-neckindex(NHI)inDunn90◦ _radiographs.15 Inthelatepostoperativeperiod,thesizeofthesmallestjoint spaceinmillimeters,the␪␣_{,andtheNHIwereassessedfor} comparisonwithpre-operativemeasurements;thepresence ofheterotopic hip ossification was assessedin accordance withBrookeretal.18_{Toavoidinter-andintra-observererrors,} themeasurementsweremadebytwosurgeonsfromthehip group.Incasesofdisagreementofmorethanthreedegreesin theangularmeasurementsorofmorethan1mminthe min-imumjointspace,anewevaluationwasperformedbyathird surgeon,andaconsensuswasthenreached.Themean mag-nificationoftheAPradiographofthehipwas15%,whichwas quantifiedbytheequipment.

TheWilcoxon test(SPSS version18.0,SPSS, Chicago,IL, USA)wasthe statisticalmethod usedtoanalyzethe inter-group paired variables (MHHS,NAHS, IR, alpha angle, and pre- and postoperative NHI). The Mann–Whitney test was applied for the intergroup analysis of the same variables; both tests were considered statistically significant when p<0.05. In order to assess the homogeneity between the groups,thechi-squaredtestwasappliedforthepreoperative measurements.

Results

Accordingtothepreoperativestatisticalanalysis,bothgroups wereconsideredhomogeneous.

In Group I _{(arthroscopy), the mean follow-up was 29.1} months(24–42).RegardingtheassessmentoftheMHHSscore, the mean preoperativescore was65 points(SD=9.8, range 38–77)andthemeanpostoperative,88(SD=11,range60–100), withameanpostoperativeincreaseof22.1.Accordingtothe establishedcriteria,31(75.60%)casespresentedgoodor excel-lentclinicalresults;eight(19.51%),fair;andthree(7.31%),poor. RegardingtheassessmentoftheMHHSscore,themean pre-operativescorewas68.8points(SD=12.5,range45–80)andthe meanpostoperative,92.5(SD=10,range60–100),withamean postoperative increaseof21.5.Themean pre-operativehip IRwas5◦_(SD=10◦_,range

−15◦to30◦)andpostoperative,20◦ (SD=12.5◦_,range5◦_–40◦_{),withameanpostoperativeincrease} of 16.4◦_{. Statistically significant differences were observed} (p<0.001)inthepre-andpostoperativemeasurementsofthe MHHSandNAHSclinicalscores,aswellasinhipIR.

Cam-typeFAIwasobservedin29hips(70.73%)and mixed-typeFAI,in12(28.27%).In20cases(48.78%)isolatedfemoral osteochondroplastywas performedduringthe arthroscopic surgicaltreatment;intheremaining21cases(51.21%),other complementaryprocedureswereperformed,suchas acetabu-larosteochondroplastyinmixed-typeFAIs(12cases[29.26%]), debridementoftheacetabularlabrum(sevencases[17.07%]), acetabular chondral microfracture in Outerbridge grade 4 chondral injuries(four cases[9.75%]) and labrum reattach-mentinaccordancewithFryandDombapudRibasetal.19_(five cases[12.19%]).

Regarding the preoperative radiographic evaluation, 13 cases(31.7%)presentedarthrosis classifiedasTönnisgrade 0,21 (51.21%) asTönnis1,andseven(17.07%) asTönnis2; nocaseswereclassifiedasTönnis3.ThemeanCEanglewas 35.78◦₍₂₄◦_–46◦_{).NopatientpresentedCEanglelowerthan20}◦ (hipdevelopmentaldysplasia).Inthepreoperativeperiod,the meansmallestjointspacewas3.31mm(2–4mm);no statisti-callysignificantdifferencewasobservedincomparisonwith thelatepostoperativeresult(p=1.000).Regarding thealpha angle,themeanpostoperativereductionwas32.9◦_;themean preoperativeanglewas76◦_(SD=14◦_,range60◦_–100◦_),andthe meanpostoperative,44◦_(SD=12.5◦_,range32◦_–55◦_).Regarding theHNI,themeanpostoperativeincreasewas0.10;themean preoperativevaluewas0.10(SD=0,range0.06–0.14),andthe meanpostoperative,0.20(SD=0.1,range0.16–0.32).A statisti-callysignificantdifference(p<0.001)wasobservedforthe pre-and postoperativealphaangleand HNI.Inthelate postop-erativeperiod,36cases(87.80%)didnotpresentheterotopic ossification;infourpatients(9.75%),heterotopicossification wasfoundandclassifiedasBrooker18_{grade1andonecase} (2.43%),asgrade3(Fig.1).

Fig.1–Malepatientaged28years,arthroscopicsurgerygroup.AandB,preoperativeradiographicevidenceofmixed-type FAI,CEangle:39◦_;␣angle:64◦.CandD,post-operativeradiographicimaging3yearsand2monthsafterfemoraland acetabularosteochondroplasty,combinedwithlabralre-fixation.CEangle:28◦_;␣angle:34◦.

In Group II _{(open), the mean follow-up was 52 months} (43–74). Regarding the assessment ofthe MHHS score, the meanpreoperativescorewas63points(SD=9,range48–70) andthemeanpostoperative,88(SD=22,range58–94),witha meanpostoperativeincreaseof21.7.Accordingtothe estab-lishedcriteria,12(70.58%)casespresentedgoodorexcellent clinical results;two(11.76%), fair; andthree (17.64%),poor. RegardingtheassessmentoftheNAHSscore,themean pre-operativescorewas65points(SD=11.3,range48.75–77.5)and themeanpostoperative,90(SD=20,range60–95),withamean postoperativeincreaseof20.4.Themean pre-operativehip IRwas5◦ _(SD=10◦_,range

−5◦ to20◦)andpostoperative,25◦ (SD=10◦_,range15◦_–40◦_{),withameanpostoperativeincrease} of 21.2◦_{. Statistically significant differences were observed} (p<0.001)inthepre-andpostoperativemeasurementsofthe MHHSandNAHSclinicalscores,aswellasinhipIR.

Cam-typeFAIwasobservedin12hips(70.58%)and mixed-type FAI, in five (29.42%). In 12 cases (70.58%), during the arthroscopicsurgicaltreatment,isolatedfemoral osteochon-droplastywasperformed;intheremainingfivecases(29.42%, mixed-typeFAIs),acetabularosteochondroplastywithlabral re-fixationwasalsoperformed.

Regarding thepreoperativeradiographicevaluation,nine cases(52.9%)presentedarthrosisclassifiedasTönnisgrade0, six(35.29%)asTönnis1,andtwo(11.76%)asTönnis2;nocases were classifiedasTönnis3.ThemeanCE anglewas32.82◦ (23◦_–44◦_{).NopatientpresentedCEanglelowerthan20}◦_.Inthe preoperativeperiod,themeansmallestjointspacewas3mm (2–4mm);nostatisticallysignificantdifferencewasobserved in comparison with the late postoperative result (p=0.58). Regardingthealphaangle,themeanpostoperativereduction was 32.5◦_{;the meanpreoperativeanglewas72}◦ _(SD=12.5◦_, range60◦_–90◦_{),andthemeanpostoperative,40}◦_(SD=9◦_,range 32◦_–52◦_{).RegardingtheHNI,themeanpostoperativeincrease} was0.12;themeanpreoperativevaluewas0.11(SD=0,range 0.08–0.15),andthe meanpostoperativevalue,0.22(SD=0.1, range0.2–0.3).Astatisticallysignificantdifference(p<0.001) wasobservedforthepre-andpostoperativealphaangleand HNI.Inthelatepostoperativeperiod,12cases(70.58%)didnot presentheterotopicossification;infivepatients(29.41%),the heterotopicossificationwasfoundandclassifiedasBrooker18 grade1(Fig.2).

Fig.2–Malepatientaged37years,opensurgerygroup.AandB,preoperativeradiographicevidenceofmixed-type,CE angle:32◦_;␣angle:62◦.CandD,post-operativeradiographicimaging4yearsand4monthsafterfemoralandacetabular osteochondroplasty,combinedwithlabralre-fixation.CEangle:28◦_;␣angle:32◦.

werefourcases(23.5%)ofpersistentpain;twocases(bothwith Tönnis2arthrosis)presentedprogressionofthejoint degen-erationandtotalhiparthroplastywasindicated.

No major complications, such as avascular necrosis of the femoralhead, femoralneck fracture, or infection were observed.

Accordingtothestatisticalanalysis,bothgroupspresented similarpostoperativeresultsregardingtheclinicaland radio-graphicevaluation(Tables1–3).

Discussion

Table1–Resultsofthehiparthrosisassessmentinpatientssubmittedtosurgicaltreatmentoffemoroacetabular impingement.

Groups Evaluation Time Median IQR p

Opensurgery Tönnisgrade0 Pre 9(52.9%)

Post Notassessed

Tönnisgrade1 Pre 6(35.29%)

Post Notassessed

Tönnisgrade2 Pre 2(11.76%)

Post Notassessed

Tönnisgrade3 Pre 0

Post Notassessed

Smallestjointspace(mm) Pre 3(SD1,range2to4) 1 0.58 Post 2.85(SD1.3,range1.5to4) 1.3

Arthroscopicsurgery Tönnisgrade0 Pre 13(31.7%) Post Notassessed Tönnisgrade1 Pre 21(51.21%)

Post Notassessed

Tönnisgrade2 Pre 7(17.07%)

Post Notassessed

Tönnisgrade3 Pre 0

Post Notassessed

Smallestjointspace(mm) Pre 3.31(SD1,range2to4) 1 1.000 Post 3.31(SD1,range2to4) 1

IQR,interquartilerange.

Table2–Resultsoftheradiographicmeasurementsofpatientssubmittedtosurgicaltreatmentoffemoroacetabular impingement.

Group Evaluation Time Value IQR p

Opensurgery Alphaangle(degree,median) Pre 72◦_(SD12.5◦_,range52◦_to87◦_{) 12.5 <0.001}

Post 40◦_(SD9◦_,range32◦_to48◦_{) 9}

NHI(median) Pre 0.11(SD0,range0.08to0.15) 0 <0.001 Post 0.22(SD0.1,range0.2to0.3) 0.1

CE␪(mean,degree) Pre 32.82◦₍₂₃◦_to44◦₎

Post Notassessed

Arthroscopicsurgery Alphaangle(degree,median) Pre 76◦_(SD11◦_,range60◦_to88◦_{) 14 <0.001}

Post 44◦_(SD12.5◦_,range32◦_to55◦_{) 12.5}

NHI(median) Pre 0.10(SD0,range0.06to0.14) 0 <0.001 Post 0.20(SD0.1,range0.16to0.32) 0.1

CE␪(mean,degree) Pre 35.78◦₍₂₇◦_to46◦₎

Post Notassessed

IQR,interquartilerange.

Table3–Resultsofthefunctionalclinicalevaluationofpatientssubmittedtosurgicaltreatmentoffemoroacetabular impingement.

Group Evaluation Time Median,SD,andrange IQR p

Opensurgery MHHS Pre 63(SD9,range48to70) 9 <0.001

Post 88(SD22,range58to94) 22

NAHS Pre 65(SD11.3,range48.75to77.5) 11.3 <0.001 Post 90(SD20,range60to95) 20

Internalrotation Pre 5(SD10◦_,range

−5◦to20◦) 10 <0.001 Post 25(SD10◦_,range15◦_to40◦_{) 10}

Arthroscopicsurgery MHHS Pre 65(SD9.8,range38to77) 9.8 <0.001 Post 88(SD11,range60to100) 11

NAHS Pre 68.8(SD12.5,range45to80) 12.5 <0.001 Post 92.5(SD10,range60to100) 10

Internalrotation Pre 5(SD10◦_,range

−15◦to30◦) 10 <0.001 Post 20(SD12.5◦_,range5◦_to40◦_{) 12.5}

Inthe literature,several authors have presentedresults ofthesurgicaltreatmentofFAI,whetherusingGanz’sopen approach,anteriorapproaches(Smith-Petersen,Hueter,etc.), arthroscopic technique,or thecombination ofarthroscopic technique and anterior mini-approach. To date, the Ganz approachisconsidered the gold standard FAItreatment.2,6 Theresultsare generallypositiveregardingsymptomrelief andimprovementofhipmobilityandlevelofphysicalactivity; theyalsosuggestjointpreservationinthelongterm.1–9

Moststudiesthatcomparetheopenandarthroscopic tech-niquesare comparative meta-analyses. Matsudaet al.,1 _in a comparative systematicreview, assessed 18 articles that presentedresultsofsurgicalhipdislocationtechniquesand anteriorandarthroscopicminiapproach;theyconcludedthat all ofthese techniques are capable ofimproving pain and functioninthemediumterm.However,opentechniques pre-sentedagreaternumber ofcomplicationsrelatedtolateral cutaneous-femoralnerveinjuryintheanteriorminiapproach; in surgical hip dislocation, they presenteda greater num-berofcomplicationsrelatedtothesiteofgreatertrochanter osteotomy (pseudoarthrosisand localpain). Botser et al.20 foundsimilarresultsina meta-analysisof26articles, and concludedthatthereisevidencethatthearthroscopic tech-niquepresentsfewercomplicationsandfasterrehabilitation. Recently, Domb et al.21 _{prospectively paired ten patients} undergoingsurgicaltreatment forFAIbyGanzsurgical dis-locationtechnique(meanfollow-upof24.8months)with20 patientsundergoingtreatmentthroughthearthroscopic tech-nique(meanfollow-upof25.5months).Theyconcludedthat patientssubmittedtothearthroscopictreatmentpresenteda significantlygreaterimprovementintheclinicalscores eval-uated.

The iliofemoral anterior approach described by Smith-Petersen22_{isalsousedinthetreatmentofFAI,allowingdirect} accessto the hip joint. However,it does notprovide good accesstotheacetabulumanddoesnotallowthecorrection ofalterations infemoral orientation.1 _{Injury of the lateral} femoral cutaneous nerve is the most prevalent complica-tion,whichinmostcasespresentsspontaneousresolution. Afterone year of follow-up, Ribas et al.19 _reported signifi-cantimprovementinaseriesof35FAIhipssurgicallytreated throughtheanteriorapproach.A23◦ _{increaseinhipIRwas} observed,aswellasasignificantimprovementintheclinical parametersevaluated.Regardingcomplications,femoral lat-eralcutaneousnervedysfunctionwasobservedinsixcases (17.1%),beingtransientinfive.Laudeet al.23_evaluated100 hipsoperatedwithanteriorapproachcombinedwith arthro-scopic assistance (mean follow-up of 4.9 years); a mean increaseof29.1 pointswasobservedforNAHS,and 11%of patientshadundergonearthroplastyattheendoffollow-up.

Arthroscopyhasbeenwidelydiffusedinthetreatmentof FAIduetoitsshortrehabilitationperiodandgoodaccessto thehipjoint.Complicationsareusuallyrelatedtothetimeof morefrequentinjuriessuchasthoseofthelateralpudendal andlateralfemoralcutaneousnerves,andrarerinjuriessuch astothesciaticnerve(0–12.9%).1,10–12,20_{Philliponetal.}11_used thearthroscopictechniqueforFAItreatmentin112patients (meanfollow-upof2.3years)andfoundameanincreaseof24 pointsintheMHHS,withoutcomplications.Inarecent publi-cation,BryrdandJones10_{evaluated207hips(meanfollow-up}

of 16 months) and found a mean increase of20 points in theMHHS;complicationswereobservedin1.5%ofcasesand in0.5%ofcasesprogressedtototalhiparthroplasty. Horis-bergeretal.24 _{appliedasimilartechniqueto105hipsof88} patients(meanfollow-upof2.3years)andobservedamean postoperativeincreaseof28pointsintheNAHS,witha1.9% complicationratesforsciaticorpudendalnerveneuropraxia and 11% for neuropraxia of the lateral femoral cutaneous nerve.In8.6%ofcases,therewasaneedforconversionto hiparthroplasty.

In the present study, results similar to those in the literature were observed for both groups. A postoperative improvementinthe clinicalevaluationofthe patientswas observed,andtheradiographicparametersprogressedto lev-elsconsiderednormal.Thehighernumberofhiparthroplasty indicationsintheopengroupcanbeexplainedbythelonger follow-upofthesepatients(meanof52months).Inthe arthro-scopicgroup,alowernumberofpostoperativecomplications wasobserved.Alongerfollow-upofthisgroupisnecessaryin ordertodefinewhetherthepostoperativejointpreservation andclinicalresultswillremainsatisfactory.

Thelimitationsofthepresentstudywerethesmallnumber ofpatientsintheopengroup,aswellasthepredominanceof malepatientsandtheshortfollow-uptime(29.1months)in thearthroscopicgroup.

Conclusion

Theclinicalandradiographicresultsofthearthroscopic treat-mentofFAIwere comparabletothoseofthe openanterior approach.Agreaternumberofcomplicationswereobserved intheopengroup.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

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