Adult Reconstructive Surgery of the Hip and Knee AAOS 2024 (PDF) | (2026) Self-Assessment Exam | Orthopedic Surgery Questions | American Academy of Orthopaedic Surgeons (AAOS)

ADULT RECONSTRUCTIVE SURGERY OF THE HIP AND KNEE – AAOS – 2024 –
COMPLETE SELF-ASSESSMENT EXAMINATION WITH SCORED PRACTICE
QUESTIONS AND ANSWER EXPLANATIONS

, Questionfg1
fg

Whatfgfactorfgisfgassociatedfgwithfgafghigherfgriskfgoffgdislocationfgafterfgtotalfghipfgarthroplasty?

A. Malefggender
B. Previousfghipfgsurgery
C. Afgdirectfglateralfgsurgicalfgapproach
D. Metal-on-metalfgbearingfgsurfaces
CORRECTfgANSWERfg:fg

BfgDISCUSSION:

Dislocationfgafterfgtotalfghipfgarthroplastyfgisfgafgmultifactorialfgproblem.fgNumerousfgriskfgfactorsfgmayfgactfgind
ependentlyfgorfgcumulativelyfgtofgincreasefgthefgriskfgoffgthisfgcomplication.fgPreviousfghipfgsurgeryfgoffganyfgkindfg
isfgassociatedfgwithfgafgtwofoldfgincreasedfgriskfgforfgdislocation.fgOtherfgriskfgfactorsfgincludefgfemalefggender,fgi
mpairedfgmentalfgstatus,fginflammatoryfgarthritis,fgandfgolderfgage.fgNumerousfgstudiesfghavefgshownfgafglowerfgd
islocationfgratefgwithfgafgdirectfglateralfgapproach,fgalthoughfgsurgicalfgtechniquesfgsuchfgasfgcapsularfgrepairfghav
efgsignificantlyfgloweredfgthefgincidencefgoffgdislocationfgafterfgusingfgthefgposteriorfgapproach.fgMetal-on-
metalfgbearingsfghavefgbeenfgassociatedfgwithfgotherfgcomplicationsfgsuchfgasfgadversefgtissuefgreactionsfgbutfgarefgoft
enfgusedfgwithfglarger-diameterfgbearings,fgwhichfgposefgafglowerfgriskfgoffgdislocation.
fg Questionfg2

fgAfgpatientfghasfgpainfg2fgyearsfgafterfgundergoingfgafgmetal-on-
metalfg(MOM)fgleftfgtotalfghipfgarthroplastyfg(THA).fgWhichfgtest(s)fgbestfgcorrelatefgwithfgafgprognosisfgiffgthisfgpatient
fgisfghavingfgafgreactionfgtofgmetalfgdebris?



A. Erythrocytefgsedimentationfgrate,fgC-reactivefgprotein,fgandfgwhitefgbloodfgcellfgcount
B. Serumfgcobaltfgandfgchromiumfgionfglevels
C. MRIfgwithfgmetalfgartifactfgreductionfgsequencefg(MARS)
D. CTfgoffgpelvis
CORRECTfgANSWER:fg

CfgDISCUSSION:

PainfulfgMOMfgTHAfgandfgtaperfgcorrosionfgcanfgcausefgsubstantialfgdamagefgtofgafgpatient'sfghipfgiffgleftfguntreate
d.fgInfgthisfgcase,fgthefgworkupfgforfgafgpainfulfgMOMfgTHAfgstartsfgthefgsamefgasfgafgworkupfgforfgafgpainfulfgmetal-
on-
polyethylenefgbearingfgcouple.fgInfectionfgmustfgbefgruledfgoutfginfgeveryfgcasefgwithfgafgsetfgoffginflammatoryfgmarkers
.fgIffgthesefgmarkersfgarefgremotelyfgelevated,fgthisfgisfganfgindicationfgforfgjointfgaspiration.fgInfgpatientsfgwithfgmet
alfgdebris,fgthefgpathologyfgreportfgoftenfgindicatesfgtoofgmanyfgcellsfgtofgcountfgorfgcellularfgdebris.fgMetalfgionfglev
elsfgdofgnotfgseemfgtofgcorrelatefgwithfgprognosis.fgTherefgarefgwell-
functioningfgpatientsfgwithfghighfgionfglevelsfgandfgpoor-
functioningfgpatientsfgwithfglowfgionfglevels.fgAdvancedfgimagingfgwithfgMARSfgMRIfgtofgevaluatefgforfgperitroc
hantericfgfluidfgcollection,fgafgsoft-
tissuefgmass,fgorfgsynovial/capsularfghypertrophyfgwillfgrevealfgsignsfgoffgafgmetalfgreactionfgthatfgindicatefgthefgnee
dfgforfgafgrevisionfgdiscussion.fgAfgCTfgscanfgcanfgshowfgmorefgadvancedfgbonyfgdestructionfgasfganfgindicatorfgoffgpoorfg
prognosis.fgThesefgfilmsfgcanfgbefgusedfgtofgdeterminefgthefgneedfgforfgafgstructuralfggraftfgorfgaugmentsfgforfgreconstru
ctionfgoffgbonefglossfgattributablefgtofgmetalfgdebris.
fg Questionfg3

Figuresfgbelowfgdemonstratefgthefgradiographsfgobtainedfgfromfgafg35-year-oldfgwomanfgwithfgend-
fg

stagefgdebilitatingfgosteoarthritisfgoffgthefgrightfghip.fgShefgisfgcontemplatingfgtotalfghipfgarthroplastyfg(THA).fgSh
efghasfgafghistoryfgoffgrightfghipfgdysplasiafgandfgunderwentfghipfgosteotomyfgasfganfgadolescent.fgOverfgthefgyears,fg
nonsurgicalfgtreatment,fgincludingfgweightfgloss,fgactivityfgmodifications,fgandfgintra-

,articularfginjections,fghasfgfailed.fgHerfginfectionfgwork-
upfgrevealsfglaboratoryfgfindingsfgwithinfgdefinedfglimits.fgAfgfurtherfgwork-
upfgrevealsfgelevationsfginfgserumfgcobaltfgandfgchromiumfglevelsfgandfgfluidfgcollectionsfgsurroundingfgthefghipfgo
nfgMRIfgwithfgMARS.fgRevisionfgTHAfgisfgrecommended.fgThefgmostfgcommonfgcomplicationfgfollowingfgrevisi
onfgoffgafgfailedfgmetal-on-metalfghipfgarthroplastyfgis

, A. infection.
B. instability.
C. loosening.
D. periprostheticfgfracture.
CORRECTfgANSWER:fg

BfgDISCUSSION:

THAfghasfgprovenfgdurablefgandfgreliablefgforfgpainfgrelieffgandfgimprovingfgfunctionfgforfgpatientsfgwithfgend-
stagefgarthritis.fgAppropriatefgbearingfgselectionfgisfgcriticalfgtofgminimizefgwearfgandfghipfgcomplications.fgAfgme
tal-on-
metalfgarticulationfgisfgassociatedfgwithfgexcellentfgwearfgratesfginfgvitro.fgWithfgitsfgcapacityfgtofgofferfgafglowfgwea
rfgratefgwithfglargefgfemoralfgheads,fgitfgisfganfgattractivefgbearingfgchoicefgforfgTHA.fgHowever,fglocalfgsoft-
tissuefgreactions,fgpseudotumors,fgandfgpotentialfgsystemicfgreactionsfgincludingfgrenalfgfailure,fgcardiomyopat
hy,fgcarcinogenesis,fgandfgpotentialfgteratogenesisfgwithfgpotentialfgtransferfgoffgmetalfgionsfgacrossfgthefgplacentalfgba
rrierfgmakefgmetal-on-
metalfgbearingsfglessfgdesirablefgandfgrelativelyfgcontraindicatedfgforfgyoungerfgwomenfgoffgchild-
bearingfgage.fgThefgworkupfgoffgafgpainfulfgmetal-on-
metalfghipfgarthroplastyfgnecessitatesfgafgsystematicfgapproach.fgSeveralfgalgorithmsfghavefgbeenfgproposed.fgRou
tinefglaboratoryfgstudiesfgincludingfgsedimentationfgrate,fgCRP,fgandfgserumfgcobaltfgandfgchromiumfgionfglevelsfg
shouldfgbefgobtainedfgforfgallfgpatientsfgwithfgpain.fgAdvancedfgimagingfgincludingfgMARSfgMRIfgshouldfgbefgper
formedfgtofgevaluatefgforfgthefgpresencefgoffgfluidfgcollections,fgpseudotumors,fgandfgabductorfgmechanismfgdestr
uction.fgInfectionfgcanfgcoexistfgwithfgmetal-on-
metalfgreactions,fgso,fgwhenfgindicatedfg(iffgthefgCRPfglevelfgisfgelevated),fgafghipfgarthrocentesisfgshouldfgbefgobtai
ned.fgHowever,fginfgthisfgsetting,fgafgmanualfgcellfgcountfgandfgdifferentialfgshouldfgbefgobtainedfgbecausefganfgauto
matedfgcellfgcounterfgmayfgprovidefgfalselyfgelevatedfgcellcounts.fgThefgresultsfgoffgrevisionfgsurgeryfgforfgafgfaile
dfgmetal-on-
metalfghipfgprosthesisfgcanfgbefgvariable.fgThefgamountfgoffglocalfgtissuefgdestructionfgandfgthefgintegrityfgoffgthefghi
pfgabductorfgmechanismfgcanfggreatlyfginfluencefgoutcomes.fgInstabilityfgisfgthefgmostfgcommonfgcomplicationfgf
ollowingfgrevisionfgoffgfailedfgmetal-on-metalfghipfgreplacements.
fgQuestionfg4

Figurefg1fgshowsfgthefgradiographfgandfgFigurefg2fgshowsfgthefgMRIfgscanfgobtainedfgfromfgafg37-year-
fg

oldfgwomanfgwithfgafg2-