A summary of fractures of acetabulum

Acetabulum fractures, Anatomy, Classification, Surgical Approaches and Management

1. A summary of fractures of
Acetabulum
A Topic Presentation at Amala Institute of Medical Sciences, Thrissur
by Dr. Libin Thomas Manathara
September 2017

2. PART 1

4. ANATOMY

5. ANATOMY
•Fromthelateralaspectofthepelvis,the
innominateosseousstructuralsupportof
theacetabulummaybeconceptualizedas
atwo-columnedconstruct(Judetand
Letournel)forminganinvertedY
•Anteriorcolumn(iliopubiccomponent):
Thisextendsfromtheiliaccresttothe
symphysispubisandincludestheanterior
walloftheacetabulum
(A) A diagram of the two columns as an
inverted Y supporting the acetabulum
(B) The two columns are linked to the
sacral bone by the “sciatic buttress”

6. ANATOMY
•Posteriorcolumn(ilioischial
component):Thisextendsfrom
thesuperiorglutealnotchtothe
ischialtuberosityandincludes
theposteriorwallofthe
acetabulum
•Acetabulardome:Thisisthe
superiorweight-bearingportion
oftheacetabulumatthe
junctionoftheanteriorand
posteriorcolumns,including
contributionsfromeach

7. ANATOMY
•(A)Lateralaspectofthehemipelvisand
acetabulum
•Theposteriorcolumnischaracterizedbythe
denseboneatthegreatersciaticnotchand
followsthedottedlinedistallythroughthecenter
oftheacetabulum,theobturatorforamen,and
theinferiorpubicramus
•Theanteriorcolumnextendsfromtheiliaccrest
tothesymphysispubisandincludestheentire
anteriorwalloftheacetabulum
•Fracturesinvolvingtheanteriorcolumn
commonlyexitbelowtheanterior-inferioriliac
spineasshownbytheheavydottedline

8. ANATOMY
•(B)Thehemipelvisfromits
medialaspect,showingthe
columnsfromthequadrilateral
plate
•Theareabetweentheposterior
columnandtheheavydotted
line,representingafracture
throughtheanteriorcolumn,is
oftenconsideredthesuperior
domefragment

9. ANATOMY
•Corona mortis
•A vascular communication between the
external iliacor deep inferior epigastric
artery and the obturator artery which may
be visualised within the Stoppa approach or
second window of the ilioinguinal approach
•Present in up to 10 to 15%of patients
•May extend over the superior pubic ramus;
average distance from the symphysis to
corona, 6 cm
•Ascending branch of medial circumflex
•Main blood supply to femoral head
•Deep to quadratus femoris
•Superior gluteal neurovascular bundle
•Emerges from the greater sciatic notch

11. MECHANISM OF INJURY

12. MECHANISM OF INJURY
•Likepelvisfractures,theseinjuriesare
mainlycausedbyhighenergytrauma
secondarytoamotorvehicle,
motorcycleaccident,orfallfroma
height
•Thefracturepatterndependsonthe
positionofthefemoralheadatthe
timeofinjury,themagnitudeofforce,
andtheageofthepatient

13. MECHANISM OF INJURY
•Directimpacttothegreater
trochanterwiththehipinneutral
positioncancauseatransverse
typeofacetabularfracture(an
abductedhipcausesalow
transversefracture,whereasan
adductedhipcausesahigh
transversefracture)

14. MECHANISM OF INJURY
•Anexternallyrotatedandabductedhip
anteriorcolumninjury
•Aninternallyrotatedhipcauses
posteriorcolumninjury

15. MECHANISM OF INJURY
•Withindirecttrauma(e.g.,a
“dashboard”-typeinjurytothe
flexedknee),asthedegreeof
hipflexionincreases,the
posteriorwallisfracturedinan
increasinglyinferiorposition
•Similarly,asthedegreeofhip
flexiondecreases,thesuperior
portionoftheposteriorwallis
morelikelytobeinvolved

16. CLINICAL EVALUATION

17. CLINICAL EVALUATION
•Traumaevaluationisusuallynecessary,withattentiontoairway,
breathing,circulation,disabilityandexposure,dependingonthe
mechanismofinjury
•Patientfactors,suchas
•patientage
•degreeoftrauma
•presenceofassociatedinjuries
•generalmedicalconditionareimportantbecausetheyaffecttreatment
decisionsaswellasprognosis

18. CLINICAL EVALUATION
•Carefulassessmentofneurovascularstatusisnecessary,because
sciaticnerveinjurymaybepresentinupto40%ofposteriorcolumn
disruptions
•Femoralnerveinvolvementwithanteriorcolumninjuryisrare,
althoughcompromiseofthefemoralarterybyafracturedanterior
columnhasbeendescribed
•Thepresenceofassociatedipsilateralinjuriesmustberuledout,with
particularattentiontotheipsilateralkneeinwhichposterior
instabilityandpatellarfracturesarecommon

19. RADIOGRAPHIC
EVALUATION

20. RADIOGRAPHIC EVALUATION
•Ananteroposterior(AP)andtwoJudetviews(iliacandobturator
obliqueviews)shouldbeobtained
•APview:Anatomiclandmarksinclude
•theiliopectinealline(limitofanteriorcolumn)
•theilioischialline(limitofposteriorcolumn)
•theanteriorlip
•theposteriorlip
•andthelinedepictingthesuperiorweight-bearingsurfaceoftheacetabulum
terminatingasthemedialteardrop

23. Case courtesy of Dr Benoudina Samir,
Radiopaedia.org, rID: 42261

24. Case courtesy of Dr Jeremy
Jones, Radiopaedia.org, rID:
28928

25. RADIOGRAPHIC EVALUATION
•Iliacobliqueradiograph(45-degreeexternalrotationview):Thisbest
demonstratestheposteriorcolumn(ilioischialline),theiliacwing,
andtheanteriorwalloftheacetabulum

28. RADIOGRAPHIC EVALUATION
•Obturatorobliqueview(45-degreeinternalrotationview):Thisisbest
forevaluatingtheanteriorcolumnandposteriorwallofthe
acetabulum

31. RADIOGRAPHIC EVALUATION
•Computedtomography(CT)
•Thisprovidesadditionalinformationregardingsizeandpositionof
columnfractures,impactedfracturesoftheacetabularwall,retained
bonefragmentsinthejoint,degreeofcomminution,andsacroiliac
jointdisruption
•Three-dimensionalreconstructionallowsfordigitalsubtractionofthe
femoralhead,resultinginfulldelineationoftheacetabularsurface
•TheCTscanisanessentialadjuncttothethreeradiographic
projectionstofurtherdefinethefracturepatternandassessfor
associatedbonyinjuries.However,itdoesnotcompletelyreplacethe
standardradiographicevaluation-Pg.1901,Rockwood8thEdition

32. CLASSIFICATION

33. CLASSIFICATION
•Judet-Letournel
•Based on degree of columnar damage, there are 10 fracture patterns,
5 “elementary” and 5 “associated”

35. Elementary Fractures

36. Elementary Fractures-Posterior wall fracture
•Thisinvolvesaseparationofposteriorarticular
surface
•Mostoftheposteriorcolumnisundisturbed
•Itisoftenassociatedwithposteriorfemoralhead
dislocation
•Theposteriorwallfragmentisbestvisualizedonthe
obturatorobliqueview
•“Marginalimpaction”isoftenpresentinposterior
fracture–dislocations(articularcartilageimpacted
intounderlyingcancellousbone)
•Marginalimpactionisidentifiedin25%ofposterior
fracture–dislocationsrequiringopenreduction
•ThisisbestappreciatedonCTscan

37. Elementary Fractures-Posterior column fracture
•Theischiumisdisrupted
•Thefracturelineoriginatesatthe
greatersciaticnotch,travelsacross
theretroacetabularsurface,and
exitsattheobturatorforamen
•Theischiopubicramusisfractured
•Medialdisplacementofthefemoral
headcanoccur

38. Elementary Fractures-Anterior wall fracture
•Disruptionofasmallportionofthe
anteriorroofandacetabulumoccurs
•Muchofanteriorcolumnis
undisturbed
•Theischiopubicramusisnotfractured
•Theteardropisoftendisplaced
mediallywithrespecttotheilioischial
line

39. Elementary Fractures-Anterior column fracture
•Thisisassociatedwithdisruptionofthe
iliopectinealline
•Itisoftenassociatedwithanteromedial
displacementofthefemoralhead
•Itisclassifiedaccordingtothelevelatwhichthe
superiormarginofthefracturelinedividesthe
innominatebone:low,intermediate,orhigh
pattern
•Themoresuperiorlythefracturelineascends,
thegreatertheinvolvementoftheweight-
bearingaspectoftheacetabulum
•CTmaybehelpfulindelineatingthedegreeof
articularsurfaceinvolvement

40. Elementary Fractures-Transverse fracture
•Theinnominateboneisseparatedintotwofragments,dividingthe
acetabulararticularsurfaceinoneofthreeways:
•1.Transtectal:throughtheacetabulardome
•2.Juxtatectal:throughthejunctionoftheacetabulardomeand
fossaacetabuli
•3.Infratectal:throughthefossaacetabuli
•Themoresuperiorthefractureline,thegreaterthedisplacementof
theacetabulardomewillbe

42. Elementary Fractures-Transverse fracture
•Thefemoralheadfollowsthe
inferiorischiopubicfragment
andmaydislocatecentrally
•Theilioischiallineandteardrop
maintainanormalrelationship
•CTtypicallydemonstratesanAP
fractureline

43. Associated Fractures

44. Associated Fractures-Associated posterior column
and posterior wall fracture
•Twoelementaryfracturepatterns
arepresent
•Theposteriorwallisusually
markedlydisplaced/rotatedin
relationtotheposteriorcolumn
•Thisinjuryrepresentsonepatternof
posteriorhipdislocationthatis
frequentlyaccompaniedbyinjuryto
thesciaticnerve

45. Associated Fractures-T-shaped fracture
•Thiscombinesatransversefractureof
anytype(transtectal,juxtatectal,or
infratectal)withanadditionalvertical
fracturelinethatdividesthe
ischiopubicfragmentintotwoparts
•Theverticalcomponent,orstem,may
exitanteriorly,inferiorly,orposteriorly
dependingonthevectorofthe
injuriousforce
•Theverticalcomponentisbestseenon
theobturatorobliqueview

46. Associated Fractures-Associated transverse and
posterior wall fracture
•Theobturatorobliqueviewbest
demonstratesthepositionofthe
transversecomponentaswellasthe
posteriorwallelement
•ByCT,intwo-thirdsofcases,the
femoralheaddislocatesposteriorly;
inone-thirdofcases,thehead
dislocatescentrally
•Marginalimpactionmayexist;thisis
bestevaluatedbyCT

47. Associated Fractures-Associated anterior column
and posterior hemitransverse fracture
•Thiscombinesananteriorwallor
anteriorcolumnfracture(ofanytype)
withafracturelinethatdividesthe
posteriorcolumnexactlyasitwoulda
transversefracture
•Itistermedahemitransversebecause
the“transverse”componentinvolves
onlyonecolumn
•Importantly,inthisfractureapieceof
acetabulararticularsurfaceremains
nondisplacedandisthekeyfor
operativereductionofotherfragments

48. Associated Fractures-Both-column fracture
•Thisisthemostcomplextypeofacetabular
fracture,formerlycalleda“central
acetabularfracture”
•Bothcolumnsareseparatedfromeach
otherandfromtheaxialskeleton,resulting
ina“floating”acetabulum
•The“spur”signabovetheacetabulumonan
obturatorobliqueradiographis
pathognomic
•Thespursignrepresentsthedistal-most
portionofthefracturediliumthatisstill
attachedtotheaxialskeleton

49. PART 2

50. TREATMENT

51. TREATMENT
•Thegoaloftreatmentisanatomicrestorationofthearticularsurfacetopreventposttraumatic
arthritis

52. Initial Management
•Thepatientisusuallyplacedinskeletaltractiontoallowforinitialsoft
tissuehealing,allowassociatedinjuriestobeaddressed,maintainthe
lengthofthelimb,andmaintainfemoralheadreductionwithinthe
acetabulum

53. Nonoperative
•Asystemforroughlyquantifyingtheacetabulardomefollowing
fracturecanbeemployedusingthreemeasurements:
•themedialroofarc-measuredontheAPview
•anteriorroofarc-measuredonobturatorobliqueview
•posteriorroofarcmeasuredoniliacobliqueview
•Theroofarcisformedbytheanglebetweentwolines,onedrawn
verticallythroughthegeometriccenteroftheacetabulum,theother
fromthefracturelinetothegeometriccenter
•Roofarcanglesareoflimitedutilityforevaluationofbothcolumn
fracturesandposteriorwallfractures

54. Nonoperative
•Nonoperativetreatmentmaybeappropriatein:
•Displacementoflessthan2to5mminthedome,dependingonthe
locationofthefractureandpatientfactors,withmaintenanceof
femoralheadcongruencyoutoftraction,andanabsenceof
intraarticularosseousfragments
•Distalanteriorcolumnortransverse(infratectal)fracturesinwhich
femoralheadcongruencyismaintainedbytheremainingmedial
buttress

56. Nonoperative
•Fractureswithamedialroofarcangleofgreaterthan45degrees,an
anteriorroofarcangleofgreaterthan25degrees,andaposterior
roofarcangleofgreaterthan70degreeshavesufficientintact
acetabulumfornonoperativetreatment
•Morerecentbiomechanicalstudysuggeststhatwiththeacetabulum
subjectedtosit-to-standloading,ratherthansingle-leg-stance
loading,thecriticalanglesaresignificantlyhigher,requiringamedial
roofarcof90.9degrees,ananteriorroofarcof67.3degrees,anda
posteriorroofarcof101.4degrees

57. Operative
•Surgicaltreatmentisindicatedfor:
•Displacedacetabularfractures(>2to3mm)
•Inabilitytomaintainacongruentjointoutoftraction
•Largeposteriorwallfragment
•Removalofaninterposedintraarticularloosefragment
•Afracture-dislocationthatisirreduciblebyclosedmethods

58. Operative-Surgical timing
•Surgeryshouldbeperformedwithin2weeksofinjury
•Itrequires
•Awell-resuscitatedpatient
•Anappropriateradiologicworkup
•Anappropriateunderstandingofthefracturepattern
•Anappropriateoperativeteam

59. Operative
•Surgicalemergenciesinclude:
•Openacetabularfracture
•New-onsetsciaticnervepalsyafterclosedreductionofhipdislocation
•Irreducibleposteriorhipdislocation
•Medialdislocationoffemoralheadagainstcancellousbonesurfaceofintact
ilium

60. Operative-Morel-LavalleLesion (Skin Degloving Injury)
•Thisisinfectedinone-thirdofcases
•Thisrequiresthoroughdebridementbeforedefinitivefracturesurgery

61. Stability
•Instabilityismostcommoninposteriorfracturetypesbutmaybe
presentwhenlargefracturesofthequadrilateralplateallowcentral
subluxationofthefemoralheadoranteriorwithmajoranteriorwall
fractures
•Centralinstabilityresultswhenaquadrilateralplatefractureisof
sufficientsizetoallowforcentralsubluxationofthefemoralhead
•Amedialbuttresswithaspringplateorcerclagewireisnecessaryto
restorestability
•Anteriorinstabilityresultsfromalargeanteriorwallfractureoras
partofananteriortypefracturewithposteriorhemitransverse
fracture

62. Congruity
•Incongruityofthehipmayresultinearlydegenerativechangesand
posttraumaticosteoarthritis
•EvaluationisbestmadebyCT
•Acceptanceofincongruityisbasedonthelocationwithintheacetabulum
•Displaceddomefracturesrarelyreducewithtraction;surgeryisusually
necessaryforadequaterestorationoftheweight-bearingsurface
•HightransverseorT-typefracturesareshearinginjuriesthataregrossly
unstablewhentheyinvolvethesuperior,weight-bearingdome
•Nonoperativereductionisvirtuallyimpossible,whereasoperativereduction
canbeextremelydifficult

63. Congruity
•Displacedboth-columnfractures(floatingacetabulum):Surgeryis
indicatedforrestorationofcongruenceiftherooffragmentis
displacedandsecondarycongruencecannotbeobtainedorifthe
posteriorcolumnisgrosslydisplaced
•Retainedosseousfragmentsmayresultinincongruityoraninability
tomaintainconcentricreductionofthefemoralhead
•Avulsionsoftheligamentumteresneednotberemovedunlessthey
areofsubstantialsize

64. Congruity
•Femoralheadfracturesgenerallyrequireopenreductionandinternal
fixationtomaintainsphericityandcongruity
•Softtissueinterpositionmaynecessitateoperativeremovalofthe
interposedtissues
•Assessmentofreductionincludes:
•Restorationofpelviclines
•ComparisontocontralateralhiponAPpelvisxray
•Concentricreductiononallthreeviews
•Thegoalofanatomicreduction

65. Surgical Approaches
•ApproachestotheacetabulumincludetheKocher-Langenbach
ilioinguinalandextendediliofemoral.Nosingleapproachprovides
idealexposureofallfracturetypes.Properpreoperativeclassification
ofthefractureconfigurationisessentialtoselectingthebestsurgical
approach.

66. Kocher-Langenbach
•Indications
•Posteriorwallfractures
•Posteriorcolumnfractures
•Posteriorcolumn/posteriorwallfractures
•Juxtatectal/infratectaltransverseortransversewithposteriorwallfractures
•SomeT-typefractures
•Access
•Entireposteriorcolumn
•Greaterandlessersciaticnotches
•Ischialspine
•Retroacetabularsurface
•Ischialtuberosity
•Ischiopubicramus

67. Kocher-Langenbach
•Limitations
•Superioracetabularregion
•Anteriorcolumn
•Fractureshighingreatersciaticnotch
•Complications
•Sciaticnervepalsy:10%
•Infection:3%
•Heterotopicossification:8%to25%

68. Ilioinguinal
•Indications
•Anteriorwall
•Anteriorcolumn
•Transversewithsignificantanteriordisplacement
•Anteriorcolumn/posteriorhemitransverse
•Both-column

69. Ilioinguinal
•Access
•Sacroiliacjoint
•Internaliliacfossa
•Pelvicbrim
•Quadrilateralsurface
•Superiorpubicramus
•Limitedaccesstoexternaliliacwing

70. Ilioinguinal
•Complications
•Directhernia:1%
•Significantlateralfemoralcircumflexarterynervenumbness:23%
•Externaliliacarterythrombosis:1%
•Hematoma:5%
•Infection:2%

71. Extended iliofemoral
•Indications
•TranstectaltransverseplusposteriorwallorT-shapedfractures
•Transversefractureswithextendedposteriorwall
•T-shapedfractureswithwideseparationsoftheverticalstemofthe“Tâ€
orthosewithassociatedpubicsymphysisdislocations
•Certainassociatedbothcolumnfractures
•Associatedfracturepatternsortransversefracturesoperatedonmorethan
21daysfollowinginjury

72. Extended iliofemoral
•Access
•Externalaspectoftheilium
•Anteriorcolumnasfarmedialastheiliopectinealeminence
•Posteriorcolumntotheupperischialtuberosity
•Complications
•Infection:2%to5%
•Sciaticnervepalsy:3%to5%
•Heterotopicossification:20%to50%withoutprophylaxis

73. Postoperative Care
•Indomethacinorirradiationisindicatedforheterotopicossification
prophylaxis
•Chemicalprophylaxis,sequentialcompressiondevices,and
compressivestockingsforthromboembolicprophylaxisare
recommended
•Mobilizationoutofbedisindicatedasassociatedinjuriesallow,with
pulmonarytoiletandincentivespirometry
•Fullweightbearingontheaffectedextremityshouldbewithhelduntil
radiographicsignsofunionarepresent,generallyby8to12weeks
postoperatively

74. COMPLICATIONS

75. COMPLICATIONS
•Surgicalwoundinfection:
•Theriskisincreasedsecondarytothepresenceofassociated
abdominalandpelvicvisceralinjuries
•Localsofttissueinjuryfromtheoriginalimpactforcemaycause
closeddeglovingorlocalabrasions
•Postoperativehematomaformationoccursfrequently,further
contributingtopotentialwoundinfection

76. COMPLICATIONS
•Nerveinjury
•Sciaticnerve:TheKocher-Langenbachapproachwithprolongedorforceful
tractioncancausesciaticnervepalsy(mostoftentheperonealbranch;
incidence,16%to33%)
•Theuseofsomatosensory-evokedpotentialsmaydecreasetheriskofsciatic
injuryinposteriorapproaches
•Femoralnerve:Theilioinguinalapproachmayresultintractioninjurytothe
femoralnerve
•Rarely,thefemoralnervemaybelaceratedbyananteriorcolumnfracture
•Superiorglutealnerve:Thisismostvulnerableinthegreatersciaticnotch
•Injurytothisnerveduringtraumaorsurgerymayresultinparalysisofthehip
abductors,oftencausingseveredisability

77. COMPLICATIONS
•Heterotopicossification:
•Theincidencerangesfrom3%to69%,highestwiththeextended
iliofemoralapproachandsecondhighestwiththeKocher-Langenbach
•Thehighestriskisayoungmalepatientundergoingaposterolateral
extensileapproachinwhichmuscleisremoved
•Thelowestriskiswithuseoftheilioinguinalapproach
•Bothindomethacinandlow-doseradiationhavebeenhelpfulin
reducingtheincidenceofthiscomplication

78. COMPLICATIONS
•Avascularnecrosis:
•Thisdevastatingcomplicationoccursin6.6%ofcases,mostlywith
posteriortypesassociatedwithhigh-energyinjuries
•Chondrolysis:
•Thismayoccurwithnonoperativeoroperativetreatment,resultingin
posttraumaticosteoarthritis
•Concentricreductionwithrestorationofarticularcongruitymay
minimizethiscomplication

79. THANK YOU
Dr. Libin Thomas Manathara