management of infection in total hip and knee … joint infection - mr...aspiration / biopsy (iib/b)...
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Portsmouth Audit Portsmouth Audit
Discussion Discussion -- February 2007February 2007
Management of infection Management of infection
in Total Hip and Knee in Total Hip and Knee
ArthroplastyArthroplasty
Simon TilleySimon Tilley
An Interdisciplinary ChallengeAn Interdisciplinary Challenge
Many aspects of Rx controversialMany aspects of Rx controversial
DiagnosisDiagnosis
Role of debridement & washoutRole of debridement & washout
1 stage vs 2 stage revision1 stage vs 2 stage revision
Local vs systemic antibioticsLocal vs systemic antibiotics
Incidence of deep infectionIncidence of deep infection
Varies significantly between centresVaries significantly between centres
Quoted averages range Quoted averages range 00..6 6 –– 22%%
Treatment OptionsTreatment Options
Tailor to individualTailor to individual
Operative vs suppressiveOperative vs suppressive
Pathophysiology 1Pathophysiology 1
DIRECT DIRECT
Access of bacteria from pt, theatre, personnelAccess of bacteria from pt, theatre, personnel
At time of surgery or early postAt time of surgery or early post--opop
HAEMATOGENOUSHAEMATOGENOUS
Bacteraemic event at remote siteBacteraemic event at remote site
Can happen at any timeCan happen at any time
Note: Both significantly modulated by patient factorsNote: Both significantly modulated by patient factors
Prime SuspectsPrime Suspects
Staphylococci most commonly isolated organismsStaphylococci most commonly isolated organisms
Epidermidis Epidermidis > Aureus> Aureus
Others: Others: StrepStrep
EnterococciEnterococci
Gram + cocci Gram + cocci
Rare: Gram negativeRare: Gram negative
Fungi & Mycobacteria Fungi & Mycobacteria
The Race for the SurfaceThe Race for the Surface
Host tissue vs bacteria to colonise implant Host tissue vs bacteria to colonise implant surface.surface.
Prosthesis immediately coated with host Prosthesis immediately coated with host derived “conditioning film”.derived “conditioning film”.
Film acts as media for colonisation (host vs Film acts as media for colonisation (host vs pathogenic)pathogenic)
Bacteria approach TJA through interaction of Bacteria approach TJA through interaction of physical & chemical forcesphysical & chemical forces
Pathophysiology 2Pathophysiology 2
If bacteria win race they will bind & multiplyIf bacteria win race they will bind & multiply
Prosthesis inert with no innate protectionProsthesis inert with no innate protection
S. aureusS. aureus = Affinity for metal alloys= Affinity for metal alloys
Pseudomonas Pseudomonas = Prefers polymers= Prefers polymers
Abx can also interact with implant surface to inhibit Abx can also interact with implant surface to inhibit
bacterial adherencebacterial adherence
The Glycocalyx & Antibiotic ResistanceThe Glycocalyx & Antibiotic Resistance
Most infecting organisms produce GlycocalyxMost infecting organisms produce Glycocalyx
Enhances nutritionEnhances nutrition
Exopolysaccharide barrier to host defencesExopolysaccharide barrier to host defences
Bacterial sequestration Bacterial sequestration
Result: Result: Decreased antibiotic penetrationDecreased antibiotic penetration
Increased antibiotic resistanceIncreased antibiotic resistance
Esp: S. aureus, CNS e.g. S. epidermidis & Pseudomonas sppEsp: S. aureus, CNS e.g. S. epidermidis & Pseudomonas spp
PrePre--operative diagnosis of deep operative diagnosis of deep
infectioninfection
Hx & Exam both highly variable (Hx & Exam both highly variable (IV/CIV/C))
Mostly mildMostly mild--moderate painmoderate pain
Less frequently: Less frequently:
Deep throbbing painDeep throbbing pain
Wound drainageWound drainage
ErythemaErythema
SwellingSwelling
Systemic fever, chills, malaiseSystemic fever, chills, malaise
Initial InvestigationsInitial Investigations
Plain radiographs (Plain radiographs (IIb/BIIb/B))
FBC + diff (FBC + diff (IIb/BIIb/B))
ESR (ESR (IIb/BIIb/B))
CRP (CRP (IIb/BIIb/B))
ESR & CRP 1ESR & CRP 1 Non specific indicators of systemic response to Non specific indicators of systemic response to
inflammatory processesinflammatory processes
ESR can remain elevated for 1 yr post THAESR can remain elevated for 1 yr post THA
CRP returns to baseline @ ~3/52 postCRP returns to baseline @ ~3/52 post--op (range 1op (range 1--8/52)8/52)
TestTest
SensitivitySensitivity SpecificitySpecificity PPVPPV NPVNPV
ESR (>30)ESR (>30) 0.820.82 0.850.85 0.580.58 0.950.95
CRP (> 10)CRP (> 10) 0.960.96 0.920.92 0.740.74 0.990.99
ESR + CRPESR + CRP 0.830.83 1.001.00
ESR & CRP 2ESR & CRP 2
NPV of a low ESR (~95%) more useful than NPV of a low ESR (~95%) more useful than
raised ESR (PPV 58%)raised ESR (PPV 58%)
Accuracy optimised with:Accuracy optimised with:
Combination ESR + CRPCombination ESR + CRP
Serial measurementsSerial measurements
Radiographic FindingsRadiographic Findings
Rarely diagnosticRarely diagnostic
Important to rule out other Important to rule out other sources of pain (e.g. #, HO, sources of pain (e.g. #, HO, prosthesis failure)prosthesis failure)
Infection suggested by Infection suggested by radiolucent lines, osteolysis radiolucent lines, osteolysis and scalloping or and scalloping or periosteal periosteal new bone formationnew bone formation
Speed of progression: Septic Speed of progression: Septic > Aseptic> Aseptic
RadioRadio--isotope scanning isotope scanning ((IIb/BIIb/B))
Can be useful if Can be useful if prosthesis > 18/12 prosthesis > 18/12
False Neg when False Neg when infective process infective process interferes with local interferes with local blood supplyblood supply
Addition of Ga 67 Addition of Ga 67 citrate > Tc 99citrate > Tc 99--m m alone.alone.
Aspiration / Biopsy Aspiration / Biopsy ((IIb/BIIb/B))
Allows preAllows pre--op op ΔΔ of infective of infective organismorganism
Note: Barrack paper (JBJS 1993). Note: Barrack paper (JBJS 1993). Advises against aspirAdvises against aspirnn in all in all revision casesrevision cases
High PPV but less useful if High PPV but less useful if prosthesis > 5ys or if normal prosthesis > 5ys or if normal bloodsbloods
Remember to stop Abx 2Remember to stop Abx 2--3/52 3/52 beforebefore
AspirAspirn n = B= Bx x (Williams 2004)(Williams 2004)
AuthorAuthor SensitivitySensitivity SpecificitySpecificity
Elson 1991Elson 1991 8484 8787
Roberts Roberts
19921992
8787 9595
Lachiewicz Lachiewicz
19961996
9292 9797
Spangehl Spangehl
19991999
8686 9494
Williams Williams
20042004
8080 9494
AvAv 8686 9393
OthersOthers
Frozen Section Frozen Section ((IIb/BIIb/B)) ::
Supplements surgical specimensSupplements surgical specimens
10 PMN / HPF = Sens 84%, Spec 99%10 PMN / HPF = Sens 84%, Spec 99%
PCR PCR ((IIb/BIIb/B)) ::
Pros: Allows detection in small numbers Pros: Allows detection in small numbers
Cons: Cost, no sensitivities, does not identify Cons: Cost, no sensitivities, does not identify primary agent among mixed growthprimary agent among mixed growth
Interventions 1 Interventions 1 –– Surgical DebridementSurgical Debridement
Depends on timing:Depends on timing:
≥≥ 33//52 52 = = 8484% success% success
33--66//52 52 = = 5656%%
Note:Note:
Infected THR tend to present later than TKRInfected THR tend to present later than TKR
Haematogenous infection often delayed c.f directHaematogenous infection often delayed c.f direct
Interventions 2 Interventions 2 –– Surgical prosthesis Surgical prosthesis
exchangeexchange
1 vs 2 stage 1 vs 2 stage
Best chance of maximising function & clearing Best chance of maximising function & clearing
infectioninfection
Vital that micro is as accurate & Vital that micro is as accurate &
comprehensive as posscomprehensive as poss
5x tissue specimens (new scalpel + forceps for 5x tissue specimens (new scalpel + forceps for
each)each)
Early transfer of specimens to labEarly transfer of specimens to lab
Withold intraWithold intra--op Abx until samples obtainedop Abx until samples obtained
Direct Exchange Direct Exchange ((III/BIII/B))
Improved efficacy cf debridement aloneImproved efficacy cf debridement alone
Avoids morbidity of temporary pseudarthrosis & 2Avoids morbidity of temporary pseudarthrosis & 2ndnd
major proceduremajor procedure
No opportunity for soft tissue contractureNo opportunity for soft tissue contracture
Improved outlook if good bone stockImproved outlook if good bone stock
BUTBUT
Less successful than 2 stage esp with virulent / Less successful than 2 stage esp with virulent / resistant organisms resistant organisms ( Ure K J ( Ure K J et al et al JBJS JBJS AmAm 1998)1998)
Staged Exchange Staged Exchange ((III/BIII/B))
Gold Standard?Gold Standard?
Local antibiotics +/Local antibiotics +/-- systemic (patchy evidence systemic (patchy evidence
for length of time with systemic Rx)for length of time with systemic Rx)
2 stage exchange with antibiotic spacer 2 stage exchange with antibiotic spacer
success > 90% success > 90% (Langlais F (Langlais F et al et al In: EFORT 2003) In: EFORT 2003)
SpacersSpacers
Aims:Aims:
Preserve normal relationship between structuresPreserve normal relationship between structures
Vector for local antibiotic RxVector for local antibiotic Rx
Allow reasonable attempts @ mobilisationAllow reasonable attempts @ mobilisation
Facilitate exposure @ reconstructionFacilitate exposure @ reconstruction
Straightforward to removeStraightforward to remove
Antibiotics 1 Antibiotics 1 ((III/BIII/B))
Systemic Systemic +/+/-- local local
Supplementary based on sensitivity profilesSupplementary based on sensitivity profiles Aminoglycosides e.g. GentamicinAminoglycosides e.g. Gentamicin
Glycopeptides e.g. VancomycinGlycopeptides e.g. Vancomycin
Theoretical risk of lowering mechanical strength of cement Theoretical risk of lowering mechanical strength of cement with addition of Abxwith addition of Abx
In In –– vivovivo studies suggest no decrease in strength at 13 yrs with studies suggest no decrease in strength at 13 yrs with 10% substitution (e.g. 4g Vanc / 40g Palacos)10% substitution (e.g. 4g Vanc / 40g Palacos)
Main aim is to eradicate infection. Sterile Main aim is to eradicate infection. Sterile mechanical failure preferable to septic failuremechanical failure preferable to septic failure
Antibiotics 2Antibiotics 2
Heat of cement exothermic rxn inactivates Heat of cement exothermic rxn inactivates
penicillinspenicillins
Rifampicin interfere with cement Rifampicin interfere with cement
polymerisation itselfpolymerisation itself
Timing of ReTiming of Re--implantationimplantation
Guided by:Guided by:
Clinical progressClinical progress
Serial ESR, CRPSerial ESR, CRP
? Neg joint aspirate/open biopsies after stopping ? Neg joint aspirate/open biopsies after stopping
AbxAbx
Cemented or Uncemented Prostheses? Cemented or Uncemented Prostheses?
((III/BIII/B))
Antibiotic impreg cement recommended for single Antibiotic impreg cement recommended for single
stage exchangestage exchange
Cement not mandatory for Cement not mandatory for 2 2 stage modelstage model
% Success% Success Direct ExchangeDirect Exchange TwoTwo--stage Revisionstage Revision
AntibioticAntibiotic--loaded loaded
cementcement
8686 9393
No antibioticNo antibiotic 5959 8686
Comparison of success rates for staged revision & the use of antibiotic-loaded cement
In 1641 patients collated from a nmber of individual studies (Langlais 2003)
Recommendations Recommendations –– Not controversialNot controversial
Multidisciplinary approachMultidisciplinary approach
Accurate culture & sensitivity reportsAccurate culture & sensitivity reports
Antibiotics tailored to sensitivities of infecting Antibiotics tailored to sensitivities of infecting
organismorganism
Effective debridement is keyEffective debridement is key
Tissue cultures if surgical procedure performedTissue cultures if surgical procedure performed
Local antibiotics +/Local antibiotics +/-- systemic improves systemic improves
clearanceclearance
IV/CIV/C
IV/CIV/C
IV/CIV/C
IV/CIV/C
IV/CIV/C
III/BIII/B
Ongoing DebateOngoing Debate
Limitations of debridement & washoutLimitations of debridement & washout
Role for direct exchangeRole for direct exchange
Acceptability of extra morbidity assoc with 2 Acceptability of extra morbidity assoc with 2
stage exchangestage exchange
Number of surgical attempts to clear infection Number of surgical attempts to clear infection
before microbefore micro--organism deemed unobtainableorganism deemed unobtainable
Thank youThank you