The Optimal Patient-Specific Placement of the Reverse Shoulder Component

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The Optimal Patient-Specific Placement of the Reverse Shoulder Component1

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Supervisor: Prof C. SchefferConsultant: Dr J. De BeerMasters Student:Mr S. Delport

Review of DiscussionIntroductionMotivationObjectivesReverse Shoulder Simulation SoftwareSimulation ResultsFuture WorkConclusion

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HumeralHead

GlenoidHumerusClavicleScapulaIntroductionIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusionShoulder replacement backgroundAnatomy1

IntroductionShoulder replacement backgroundAnatomy

SubscapularisSupraspinatusInfraspinatusDeltoid2AnteriorPosteriorIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

HumeralStemPolyethyleneInsertGlenosphereBaseplate

IntroductionShoulder replacement backgroundHemiarthroplastyTSARSA

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IntroductionStudy by Sperling et al. (2011)261 shoulders3 year follow-upImprovement after RSAAbduction, forward flexion, pain reliefHigh number of complications (mean, 24.4%)Scapular notching, glenoid and humeral dissociations, glenohumeral dislocation, nerve injury4IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

IntroductionDeFranco and Walch (2012)RSA clinical outcome factorsPre-operative diagnosisFunction of deltoid and rotator cuff musclesProsthesis biomechanical designOrientation and position of the reverse shoulder components5IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

MotivationIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusionEffects of reverse shoulder component placementPrevious studiesGlenohumeral motionSingle elevation planeCurrent studyShoulder complex motionCoronal, scapular and sagittal elevation planes

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ObjectivesIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusionDevelop a simulation package to determine optimal patient-specific placement of the reverse shoulder componentsAnalyse the influence of the placement of the reverse shoulder components on humerothoracic ROM and adduction deficitAnalyse the influence of the design of the reverse shoulder components on humerothoracic ROM and adduction deficit7

Reverse Shoulder Simulation SoftwareIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusionWork Flow

StartImport Patient DataSetup PatientPosition ImplantSimulateDesired ROM AchievedGenerate ReportEndnoyes8

Matlab softwareGraphical User Interface Design EnvironmentPatient dataCT scanSternum, C7 & T8, clavicle, scapula and humerusMimics software STL files

Reverse Shoulder Simulation Software9IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Reverse Shoulder Simulation SoftwareImplant data

Tornier Aequalis Reversed II SystemGlenoid ComponentsHumeral ComponentsGlenosphereBaseplateStemPolyethylene Insert 36 mm concentric 36 mm 4 mm inferior 36 mm 3 mm lateral 42 mm concentric 42 mm 4 mm inferior 42 mm 3 mm lateral 25 mm 29 mm 36 mm concentric 36 mm 2 mm inferior 36/42 mm combination 6 mm, 9 mm or 12 mm 6 mm, 9 mm or 12 mm 6 mm, 9 mm or 12 mm 10IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Shoulder coordinate systemsInternational Society of BiomechanicsThorax coordinate system

Reverse Shoulder Simulation Software11C7IJPXC7T8IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Shoulder coordinate systemsInternational Society of BiomechanicsClavicle coordinate system

Reverse Shoulder Simulation Software12ACSCIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Shoulder coordinate systemsInternational Society of BiomechanicsScapula coordinate systems

Reverse Shoulder Simulation Software13AAAISCS1SCS2AITSTSGlenoidCentreIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Shoulder coordinate systemsBoileau and Walch (1997)Humerus coordinate system

Reverse Shoulder Simulation Software14GHMELEUpper ShaftCentre Line

IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Shoulder complex motionSternoclavicular

Scapulothoracic

Upward RotationInternal RotationPosterior TiltingAcromioclavicularJoint

ElevationProtractionPosterior RotationScapulothoracicJointReverse Shoulder Simulation Software15IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Shoulder complex motionHumerothoracic

Reverse Shoulder Simulation Software16ElevationElevation Plane


Glenohumeral Rotation Centre

Reverse Shoulder Simulation SoftwareShoulder complex motion dataLudewig et al. (2009)Normal shoulders12 subjectsCoronal, scapular and sagittal elevation planes0 120 humerothoracic elevationISB standardsMotion equations


Reverse Shoulder Simulation SoftwareShoulder complex motion simulationCombined ADCombined humerothoracic ROM

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Impingement

Adduction Deficit

HumerothoracicROMIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Simulation ResultsIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusionSimulation testsValidated shoulder modelGlenoid component inclination angleHumeral component retroversion angleReaming depthComponent combinationsImplant design changes

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Simulation ResultsIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusionGlenoid component inclination

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-10 -5 0 5 10 Humeral component angles

LEME

HumerusRetroversionHead and Neck Axis

Head and Neck Axis

Neck-shaft AngleUpper ShaftCentre Line

Simulation Results21


Simulation ResultsHumeral component retroversion

353015101520253545FrequencyHumeral Component Retroversion Angle []40530400202522IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Simulation Results42 mm glenosphere

330300270240-10-50510Combined Humerothoracic ROM []Glenoid Inclination Angle []Concentric; 29 mmInferior; 29 mmLateral; 29 mmConcentric; 25 mmInferior; 25 mmLateral; 25 mm36021023IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Simulation Results42 mm glenosphere

9060300-10-50510Combined AD []Glenoid Inclination Angle []Concentric; 29 mmInferior; 29 mmLateral; 29 mmConcentric; 25 mmInferior; 25 mmLateral; 25 mm12024IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion

Simulation ResultsEccentricity design change

30027024021036 mm42 mmCombined Humerothoracic ROM []GlenosphereInferiorLateralInferior & Lateral36025IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion330

Simulation ResultsEccentricity design change

604020036 mm42 mmCombined AD []GlenosphereInferiorLateralInferior & Lateral10026IntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusion80

Simulation ResultsInclination force distribution Gutirrez et al.


Most Desirable

ConcentricLateral EccentricInferior EccentricAcceptableLeastDesirable

Simulation Results25 mm baseplate42 mm glenosphereInferior eccentric with superior inclinationCombined eccentricity for neutral inclination


Future WorkIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusionPost-operative active ROM clinical studyInclude different reverse shoulder component typesRecord large number of simulation dataDetermine patient-specific humeral component retroversion angle

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ConclusionIntroductionMotivationObjectivesRS3Simulation ResultsFuture WorkConclusionObjectives were addressed and successfully achievedMay assist surgeons in pre-operative implant selection and placement More inexperienced surgeons can attempt a RSA with greater confidenceReduce surgery cost and timeMay improve implant survival rates and long-term clinical outcomes

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Thank you

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The Optimal Patient-Specific Placement of the Reverse Shoulder Component