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The infected T.K.R. Khalil Allah. Nazem Feb 2013. In the face of an increasing prevalence of TKA, intensified efforts at infection prevention seem logical to reduce the overall burden of PJI. As an over view, prevention of PJI relies upon Augmentation of the host response - PowerPoint PPT Presentation

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The infected T.K.R

The infected T.K.R

Khalil Allah. NazemFeb 2013In the face of an increasing prevalence of TKA, intensified efforts at infection prevention seem logical to reduce the overall burden of PJI.

As an over view, prevention of PJI relies uponAugmentation of the host responseOptimization of the wound environmentReduction of bacterial contamination in the pre-intra and post operation times

In addition to prevention, a thorough understanding of the principle of diagnosis and treatment is essentialAlthough the incidence rates of infection following TKR appear to have fallen over the past several decades, the reported incidence varies in many studies

Many inherent patient risk factors are known to predispose toward post operative deep infection. Host factors include a diagnosis of RA, skin ulcers, D.M ,history of malignancy, obesity, smoking, renal or liver transplantation, HIV positive, prior open knee surgery or periarticular Fx, prior septic arthritis or osteomyelitis.Risk factors related to surgeon:Increased INR after operation hematoma require reoperation early wound healing complicationsRecent intra articular injection of corticosteroide . Prolonged operative timeProper use of AnB prophylaxis represents the single most effective method of reducing infection in TKR. Optimization of surgical environment. Use low dose ABLC in high risk patients and revision surgery. Frequent irrigation. Carful surgical technique. Excellent wound closure is important variables under the surgeon controlRisk factors related to surgeon:Hematogenous infection of TKR in early postoperative period or many years after operation is often influenced by the surgeon through education efforts made with arthroplasty patients. (Oral- genitourinary- gastrointestinal)In general invasive procedures that potentially cause bacteremia should simply avoided in the first 3-6 months.(Dental procedures greater than 75 minute in DM and RA are at higher risk). AAOS no longer has published guidelines for the use of prophylactic AnB for high risk patients (Antibiotic prophylaxis for bacteremia in patients with joint replacement.)Diagnosis

No criteria for the definitive diagnosis of PJI have attained universal agreementIt is well recognized that some true PJI have negative culture (up to 19%)Current definition of PJI includes a combination of clinical sign and symptom, histologic analysis of tissue and results of culturesThe diagnosis of definitive PJI is made if evaluation established at least one of the following criterionTwo or more positive cultureHistologicGross purulent is observed Actively discharge sinus tractIt seems reasonable to identify offending organism and enacting directed treatment strategies

In most series gram positive , may polymicrobial (9%), in current era many resistant organismMRSA and MRSE have emerged as common nosocomial pathogens often requiring complex AnBs and potentially inferior treatment outcomeResistant Infections definitely need two staged operationsFungal PJI are rare and needs two staged treatment

Identification and diagnosis of biofilm organisms is difficult

Culture independent molecular method (detection of 16s ribosomal deoxy ribonucleic acid)Culture samples obtain by sonication of prosthesis

Timing of the clinical presentation is a critical factor in diagnosisThese various clinical presentation is critical factor and classified as a useful guide to selecting the most appropriate treatment option

Classification System of Prosthetic Joint Infection: Time to Onset of Infection Dictates Treatment

Classification System of Prosthetic Joint Infection: Time to Onset of Infection Dictates Treatment


Variables that must consider before treatment include:Deep or superficialDuration from T.K.A Host factorsSoft tissues (extensor mechanism)Implant is loose or fixedPathogens responsibleAbility of surgeonPatient's expectations

Treatment goals

Eradication of infection, alleviation of pain, maintenance of functionWhen confronted with an infected T.K.A, the treating physician should start by considering the question prosthesis retain or removalTreatment methods where the prosthesis is retainedAntibiotic suppression:This method alone will not eliminate deep infection but can be used as suppression treatment when the following criteria are met Prosthesis removal is not feasibleMicroorganism has low virulence and susceptible to an oral antibiotic The antibiotic can be tolerated without serious toxicityThe prosthesis is not looseOther prosthesis or cardiac valvular prosthesis are not presentSuccess rates are 16-24%Rifampin with a quinolone has been reported to be more successful

Treatment methods where the prosthesis is retainedDebridement with prosthesis retentionThis method indicated only in infections in early post operative period or acute hematogenous with fixed and functional prosthesis and patient has this criterionShort duration of symptomsSusceptible gram-positive organism Absence of prolonged postoperative drainage or sinus tractNo prosthesis loosing No other arthroplasty or cardio vascular prosthesisSuccess rates are 19-32%Factors that worsen the results arePost operative drainage longer then 2weeksExistence of sinus tractHinged prosthesisImmune compromised hostsArthroscopy is not suitable surgical method for debridement and retentionsTreatment methods where by the prosthesis is removedResection arthroplasty:The ideal candidate is a patient with polyarticular RA with limited ambulatory demands, which allow the patient to sit more readily than is feasible with a knee arthrodesis. The primary disadvantage is mobility and pain during transfer or ambulation

Treatment methods where by the prosthesis is removedAdvantages: excellent potential for resolving infections alleviating pain, providing stable kneeDisadvantage: elimination of knee motionIndications: high functional demandsSingle joint diseaseYoung patientsExtensor mechanism disruption Poor soft tissueSystemic immunocompromiseBad micro organismArthrodesis:Relative contraindication:Bilateral knee diseaseIpsilateral hip or ankle diseaseOver segmental bone lossContralateral limb amputationMethod of Arthrodesis:

IM nailingExternal fixationDual plate fixationIM nailing appears to show a higher trend toward success union but has a higher risk of recurrent infection compare to ext fixation


Is rarely indicated except in cases if life threatening systemic sepsis or persistent local infection associated with massive bone loss.Factors must commonly leading to amputation include multiple revisions sever bone loss, intractable pain


Is currently the primary accepted method of treatment for infected T.K.A contraindications: persisted or recalcitrant infectionmedical conditions extensor mechanism disruptionsPoor soft tissue envelopeReimplantation can be performed as a direct exchange technique or two stages

Factors associated with successful direct exchange:

Infection by gram positiveAbsence of sinus formationUse of antibiotic cementedA prolonged 12week course of AB therapyThis method indicated only in groups of patients highly selected by arthroplasty surgeons familiar with the treatment of prosthetic infection

Two stage reimplantation

This protocol consist of soft tissue debridement and removal of infected prosthesis and cement, followed by 6weeks IV antibiotics and subsequent reimplantationThe success rate is 85-95%Use of adjunctive antibiotic delivery provided by the ABLC gradually lead to decrease AB duration and shorter time delays prior to reimplantationAntibiotic cement spacersLow dose ABLC (