basics of thr

8/9/2019 Basics of THR

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Basics Of THRBasics Of THR

Dr Niraj L VoraDr Niraj L Vora

Consultant Orthopaedic Joint ReplacementConsultant Orthopaedic Joint Replacement

and Trauma Surgeonand Trauma Surgeon

Kokilaben Dhirubhai Ambani HospitalKokilaben Dhirubhai Ambani Hospital


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EvolutionEvolution

Osteotomy ArthroplastyOsteotomy Arthroplasty

Interpositional ArthroplastyInterpositional Arthroplasty

Reconstructive ArthroplastyReconstructive Arthroplasty

Partial/Hemi ArthroplastyPartial/Hemi ArthroplastyTotal Hip ArthroplastyTotal Hip Arthroplasty


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EvolutionEvolution

Earliest record of hip arthroplastyEarliest record of hip arthroplasty 18271827

Various materials used, including Glass,Various materials used, including Glass,Ivory, Acrylic etcIvory, Acrylic etc

Various giants like Judet, McKee, SmithVarious giants like Judet, McKee, SmithPetersen etc tried, but were unsuccessfulPetersen etc tried, but were unsuccessful


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MARIUS SMITHMARIUS SMITH--

PETERSEN (1923)PETERSEN (1923)

Boston.Boston.

Vitallium CupVitallium CupMouldMould

ArthroplastyArthroplasty

InterpositionalInterpositional ArthoplastyArthoplasty


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OTTO E. AUFRANCOTTO E. AUFRANC

Interpositional ArthroplastyInterpositional Arthroplasty

82% success rate in82% success rate in

1000 cases (1957)1000 cases (1957)


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Sir JohnSir John CharnleyCharnley Initially teflon socketInitially teflon socket early failureearly failure wearwear

Accidentally stumbled upon HDPEAccidentally stumbled upon HDPE

Concept of Low Friction ArthroplastyConcept of Low Friction Arthroplasty22.225mm head and thick22.225mm head and thick

poly socketpoly socket

Use of cementUse of cement -- 19531953


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Dr K TDr K T DholakiaDholakiaFather of Arthroplasty in IndiaFather of Arthroplasty in India

At one time did moreAt one time did moreArthroplastiesArthroplasties than all othersthan all others

in India put togetherin India put together


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EvolutionEvolution


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Hip BiomechanicsHip Biomechanics

Centre of Hiprotation

Abductor lever arm


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Hip BiomechanicsHip Biomechanics

Frictional torque

proportional to

head diameter

Large headLarge headIncreased arc of motionIncreased arc of motion

Reduced impingementReduced impingement


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About HardwareAbout Hardware

CobaltCobalt--chromechrome

OffsetOffset Vital to preventVital to prevent

abductor lurchabductor lurch

Neck lengthNeck length will affectwill affect

leg lengthleg length

Distal stem diameterDistal stem diameter

important in mode ofimportant in mode of

fixation offixation of uncementeduncemented

implantimplant


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About HardwareAbout Hardware

Made of UHMWPE (Ultra HighMade of UHMWPE (Ultra High

Molecular WeightMolecular Weight PolyEthylenePolyEthylene) or) or

HDPEHDPE

Flange helps with cementFlange helps with cement

pressurisationpressurisation

Long posterior wall helps reduce risk ofLong posterior wall helps reduce risk ofdislocationdislocation

Grooves give greater surface area forGrooves give greater surface area for

cementcement


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Uncemented Femoral ComponentUncemented Femoral Component

TitaniumTitanium--AluminiumAluminium--VanadiumVanadium

alloyalloy

Coated withCoated with HydroxyapatiteHydroxyapatite((HAHA) or Porous (Ti) or Porous (Ti fibrefibre mesh)mesh)

Good initial primary stability isGood initial primary stability is

a must (a must (Press fitPress fit))

Depend onDepend on osteoosteo--integrationintegration

for fixation (for fixation (Biologic FixationBiologic Fixation))

Corail HipCorail Hip


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Anatomic stemAnatomic stem

Straight stemStraight stem VariableVariable

CoatingCoating

Uncemented Femoral ComponentUncemented Femoral Component


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UncementedUncemented SocketSocket

Fixation methodsFixation methods

Press fitPress fit

SpikesSpikesScrewsScrews


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Modular ComponentsModular Components

SS--ROMROM


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Custom ImplantsCustom Implants


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IndicationsIndications

Primarily, alleviation ofPrimarily, alleviation of

incapacitatingincapacitating PAINPAINSecondary is improving HipSecondary is improving Hip

Function (Mobility and stability)Function (Mobility and stability)


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PrePre--operativeoperative TemplatingTemplating


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Surgical ApproachesSurgical Approaches1.1. Posterior approachPosterior approach

2.2. AnterolateralAnterolateral approach (approach (HardingeHardinge))

3.3. TransTrans--trochanterictrochanteric approach (approach (CharnleyCharnley))

4.4. ExtendedExtended TrochantericTrochanteric OsteotomyOsteotomy (ETO)(ETO)

for Revision surgeryfor Revision surgery


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Posterior approachPosterior approach


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AcetabularAcetabular ImplantationImplantation

Avoid Bottoming OutAvoid Bottoming Out


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Femoral techniqueFemoral technique


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EntryEntry

Distal plugDistal plug

Cement gunCement gun


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Modern cementing techniquesModern cementing techniques

MedullaryMedullary brushbrush

Cement restrictor (plastic/bone/cement pCement restrictor (plastic/bone/cement plug)

MedullaryMedullary PulsatilePulsatile LavageLavage Insertion of adrenalineInsertion of adrenaline--soaked spongessoaked sponges

Reduction of cement porosity (Centrifuge and VacuumReduction of cement porosity (Centrifuge and Vacuummixing)mixing)

Cement centralizers (applied to femoral stem tip)Cement centralizers (applied to femoral stem tip)

Cement gun for retrograde insertion and pressurizationCement gun for retrograde insertion and pressurization

Pressurization: may be performed with surgeon's glovedPressurization: may be performed with surgeon's glovedfinger or with a wedge shaped device pushed into thefinger or with a wedge shaped device pushed into themedullarymedullary canalcanal


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Alternate BearingsAlternate Bearings

Ceramic on Ceramic Very low wear rate

Much smoother

Highly biocompatible

High hardness

Suitable for the younger patient


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Wear RatesWear Rates


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Articular Surface ReplacementArticular Surface Replacement

(ASR)(ASR)

ProsPros

Bone conserving

Increased hip ROMdislocation

ConsCons

Limited indicationsSteep learning curve


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Computer AssistedComputer Assisted Nav

Nav

A GPS system for joint replacementA GPS system for joint replacement

Provides individualized information to planProvides individualized information to planbony resectionbony resection

Improves accuracy in implant positioningImproves accuracy in implant positioning

Excellent training toolExcellent training tool


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Computer Assisted NavComputer Assisted Nav

Used in Resurfacing surgery

Registration process critical

No peer reviewed evidence

that use of Nav improveslong term outcomes


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ComplicationsComplications

Osteolysis

Cement DiseaseCement Disease

Cementless DiseaseCementless Disease

ZonesZ

ones


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Poly WearPoly Wear


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DislocationDislocation


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InfectionsInfections

1.1. Antibiotic therapyAntibiotic therapy

2.2. Incision and drainage of the hipIncision and drainage of the hip3.3. Debridement and modified GirdlestoneDebridement and modified Girdlestone

resection arthroplastyresection arthroplasty

4.4. OneOne-- or twoor two--stage revision to a total hipstage revision to a total hip

arthroplastyarthroplasty


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2 stage Revision



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Fractures



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