ComparisonoftheReliabilityofThreeMethodsfortheAssessmentoftheLowerLimbLength:

EOSwithNewMicro–DoseProtocolvs.Long–StandingRadiographvs.CTScanogram

BurakAbay,MehmetFa1hErol,Me1nKucukkayaIstanbulBilimUniversity

Dept.ofOrtopedicsandTraumatology,Istanbul,TURKEY

25thAnnualScien1ficMee1ngofLimbLengtheningandReconstruc1onSociety–Charleston,SC

22July2016

Disclosure• Nofinancialrela1onshipsintereststodisclose.

Introduction• Newinternalfixa1ondevices

(IMLengtheningnails,anatomicplates)• Acutecorrec1on&precisepreopera1veplanning• Needforaccurateradiologicalimagingmethods

ProblemsinacutecorrectionandinternalGixation

1)Preopera1veplanningismadebylongstandingroentgenogram• Correc1onisperformed

• Undergeneralanesthesia•  Innon-weightbearingsupineposi1on• WiththeFluoroscopyimages

2)Decisiontoendthedistrac1onperiodofthelengtheningnails

Methodsusedformeasuringlowerlimblength

Clinicaltechniques

•  TapeMeasure•  Standingonblocks

ImagingMethods

•  LongStandingroentgenogram

•  Slitscanography• Orthoroentgenogram•  Scanogram•  ComputerizedTomography(CT)scanogram

• Ultrasound• MRIScanogram•  Biplanardigitalroentgenogram

•  EOS

Imagingmethodsfordeformityandlimblengtheningsurgery

• Longstandingroentgenogram• ComputerizedTomography(CT)scanogram• EOS• Slitscanography(supineposi1on)• Orthoroentgenogram• Scanogram• MRIScanogram

Studymethod

1.  Inter-raterreliability:agreementbetween

thereaders

2.  Intra-raterreliability:agreementinthe

reader.(test–retestorreproducibility)

3. MeanAbsoluteDifferences(MAD):

betweenthethreeimagingmodali1es

Materials

• 14lowerlimbsof7pa1ents(7men;meanage,31years;range,25-46years)• Threemethodsofradiologicalimagingmodali1es•  EOS(micro-doseprotocol)• CTscanogram•  Longstandingroentgenogram

Assessment• Lengthsofbones(lowerlimb,femur,1bia)

•  Radiologictechnician•  Orthopedicsurgeon•  Seniorresident(2seperateoccasionsataminimumof4weeksapart)

• Sta1s1cs•  Meanabsolutedifference(ANOVA)•  Bland-Altmananalyses

(Agreementbetweenreadersandmodali1es)

EOStechnique

• Biplanarradiography•  Scannerpladorm• Wholelowerlimb•  Feetsamecoronalplane• Micro-doseprotocol

EOSwithmicrodoseprotocol

LongStandingroentgenogramtechnique

•  Single-exposure•  Standingfull-lengthteleroentgenogram• Patellasfacingforward• Beamtothekneejoint•  Fullextension•  300cmdistancefromtube•  20mmradioopaquesphere

LongStandingroentgenogramtechnique

•  Single-exposure•  Standingfull-lengthteleroentgenogram• Patellasfacingforward• Beamtothekneejoint•  Fullextension•  300cmdistancefromtube•  20mmradioopaquesphere

LongStandingroentgenogram

CTscanogramtechnique

•  feetenteringthegantryfirst• patellasorientedanteriorly•  asingleposteroanteriorscoutimage• Non-weightbearingposi1on

LengthmeasurementsandanalysisLongstandingroentgenogram CTScanogram EOS

PACS®CORELDRAWX7®

PACS®

DrorPaley,PrinciplesofDeformityCorrecRon

Results

•  ThemeanabsolutedifferencesforthestandingroentgenogramandCTscanogramwereallsignificantlydifferentfromthatofEOS(p<0.05).

•  6,3mm/863,7mm(wholelowerlimb)=0,7%differencebetweenEOSandLongstandingroentgenogram

•  Meanabsolutedifferencesamongthreemodali1es

ResultsInter-raterreliability

•  Inter-raterreliability,quan1fiedwithIntraclassCorrela1onCoefficients,showedexcellent(>0.90)agreementforstandingroentgenogram,CTscanogramandEOSwithmicrodoseprotocol.

•  LSR=EOS=CT

ResultsIntra-raterreliability

•  Intra-raterreliability,quan1fiedwithIntraclassCorrela1onCoefficients,showedexcellent(>0.90)agreementforstandingroentgenogram,CTscanogramandEOSwithmicrodoseprotocol.

•  LSR=EOS=CT

LongStandingroentgenogram

• Magnifica1onerrordependson

-  Lengthofthelowerlimb-  Thedistancetothetube-  Divergenceofthebeam

300cm

Sabharwaletal,2008

•  ComparisonofEOSwithCTscanogram•  InterraterandintraraterreliabilitywereexcellentforbothtotallengthandintrabeaddistanceonbothEOSandCTscanogram

•  (r>0.99andP<0.001)

•  UsingPhantomlimb(withsawbones)•  EOSwasthemostaccuratemodality•  ThemeandifferencesonbothEOSsenngs

weresignificantlydifferentfromthoseonCTscanograms,notclinicallyimportant.

•  Nocalibra1onmethodwasused.

EOSwithmicrodoseprotocol

Ar#factinslowmode

EOS–Slow EOS-microdose

16y,FSamepa1ent

23y,F

EOS=Biplanarradiography

LSR EOS

Idealmethod1.  Accurate2.  Excellentreliabilityandexcellentreproducibility3.  Readilyavailableinthephysician’soffice4.  Technicallyeasy5.  Itscostandradia1ondosageshouldbelow

Conclusion•  ThereliabilityoftheLSRissimilartoothertwomethodsifappropriatecalibra1onisdone.

•  WiththecalibraRon1mm≈1mm•  EOSmightbehelpfulduringtheendofthedistrac1onperiod•  Single–exposureLSRwiththecalibra1onmightbegoodchoicefortheassessmentandpreopera1veplanningofthelowerlimbdeformi1es.

Thankyou