Prosthetic joint infection in detail powerpoint

How to deal with prosthetic joint infection, and approach to dealing with the various scenarios

1. PROSTHETIC JOINT INFECTION DR MANDEEP PG-3 ORTHO UNIT-2

2. OVERVIEW INTRODUCTION DEFINITION RISK FACTORS CLASSIFICATION PATHOGENESIS AND ETIOLOGY CLINICAL PRESENTATION DIAGNOSIS MANAGEMENT PREVENTION

3. INTRODUCTION DESPITE ADEQUATE PRECAUTIONS AND ADVANCES IN TREATMENT MODALITIES INFECTION FOLLOWING JOINT REPLACEMENT SURGERY IS A MAJOR CONCERN WITH ASSOCIATED MORBIDITIES AND EXPENSES FOR TREATMENT. INFECTION IS ONE OF THE MOST DREADED COMPLICATIONS AFFECTING TKA PATIENTS, WITH REPORTED FREQUENCIES OF 2% TO 3% IN SEVERAL LARGE SERIES. ACCORDING TO CURRENT MEDICARE DATA, 1.5% OF PATIENTS DEVELOP A PERIPROSTHETIC INFECTION IN THE FIRST 2 YEARS AFTER TKA.

4. DEFINITION MSIS DEFINES PJI WHEN 1 MAJOR CRITERIA EXIST OR 4 OUT OF 6 MINOR CRITERIA EXIST

5. THRESHOLD FOR MINOR CRITERIA

6. RISK FACTORS POSTOPERATIVE SURGICAL SITE INFECTION REVISION SURGERY RHEUMATOID ARTHRITIS LONGER OPERATIVE PERIOD OBESITY, DIABETES, SMOKING, CHRONIC ALCOHOLIC URTI, UTI, DENTAL CARRIES, SKIN INFECTION RENAL FAILURE, POOR NUTRITION,IMMUNOCOMPROMISED, MALIGNANCY.

7. CLASSIFICATION EARLY : DEVELOPING IN THE FIRST 3 MONTHS AFTER SURGERY DELAYED : OCCURING 3-24 MONTHS AFTER SURGERY LATE : AFTER 24 MONTHS OF SURGERY

8. ACCORDING TO ROUTE OF INFECTION PERIOPERATIVE INOCULATION OF MICROORGANISMS INTO THE SURGICAL WOUND DURING SURGERY OR IMMEDIATELY THEREAFTER. HAEMATOGENOUS THROUGH BLOOD OR LYMPH SPREAD FROM A DISTATNT FOCUS OF INFECTION. CONTIGUOUS SPREAD FROM AN ADJACENT FOCUS OF INFECTION( eg : PENETRATING TRAUMA, PREEXISTING OSTEOMYELITIS, SKIN AND SOFT TISSUE LESIONS).

9. McPHERSON AND COLLEAGUES PROPOSED A STAGING SYSTEM FOR PJI

10. PATHOGENESIS INITIATION OF INFECTION: THE MAJORITY OF PJIS OCCURING WITHIN 1 YEAR OF SURGERY ARE INITIATED THROUGH THE INTRODUCTION OF MICROORGANISMS AT THE TIME OF SURGERY. THIS CAN OCCUR THROUGH EITHER DIRECT CONTACT AND AEROSOLIZED CONTAMINATION OF THE PROSTHESIS OR PERIPROSTHETIC TISSUE. ONCE IN CONTACT WITH THE SURFACE OF THE IMPLANT, MICROORGANISMS COLONIZE THE SURFACE OF THE IMPLANT( RACE FOR SURFACE ).

11. A SIGNIFICANT FACTOR IN THIS PROCESS IS THE LOW INOCULUM OF MICROORGANISMS NEEDED TO ESTABLISH INFECTION IN THE PRESENCE OF PROSTHETIC MATERIAL. CONTIGUOUS SPREAD OF INFECTION FROM AN ADJACENT SITE IS THE SECOND MECHANISM BY WHICH INFECTION CAN BE INITIATED. IN THE EARLY POSTOPERATIVE TIME PERIOD, SUPERFICIAL SURGICAL SITE INFECTION CAN PROGRESS TO INVOLVE THE PROSTHESIS. FINALLY, THE PROSTHESIS REMAINS AT RISK OF HEMATOGENOUS SEEDING THROUGHOUT THE LIFE OF THE ARTHROPLASTY.

12. ROLE OF BIOFILM A biofilm is defined as “an assemblage of microbial cells that is irreversibly associated with a surface and enclosed in a matrix of primarily polysaccharide material”

13. FORMATION OF BIOFILM

14. BIOFILM FORMATION IMPACTS THE DIAGNOSIS OF PJI. ESPECIALLY IN DELAYED AND LATE ONSET PJIs, THE IMPLICATED ORGANISMS ARE CONCENTRATED ON THE SURFACE OF THE PROSTHESIS, THUS LIMITING THE SENSITIVITY OF PERIPROSTHETIC TISSUE AND FLUID CULTURES. ONE STRATEGY TO OVERCOME THIS LIMITATION IS TO SAMPLE THE PROSTHESIS SURFACE ITSELF.

15. THE VIRULENCE OF THE INFECTING ORGANISMS IS AN IMPORTANT FACTOR TO CONSIDER IN PLANNING MANAGEMENT. STAPH AUREUS AND STAPH EPIDERMIDIS ARE THE MOST COMMON ISOLATED ORGANISMS. GRAM NEGATIVE INFECTIONS ARE RESISTANT TO TREATMENT AND ARE FREQUENT CAUSE OF RECURRENCE AFTER AN EXCHANGE ARTHROPLASTY.

16. SINUS TRACT COMMUNICATING WITH ARTHROPLASTY IS PATHOGNOMONIC OF PJI. CLINICAL PRESENTATION

17. DIAGNOSIS THE DIAGNOSIS OF PJI IS BASED UPON A COMBINATION OF CLINICAL FINDINGS, LABORATORY RESULTS FROM PERIPHERAL BLOOD AND SYNOVIAL FLUID , MICROBIOLOGICAL DATA, HISTOLOGICAL EVALUATION OF PERIPROSTHETIC TISSUE, INTRAOPERATIVE INSPECTION AND RADIOGRAPHIC RESULTS. GENERAL APPROACH TO PJI DIAGNOSIS WHETHER OR NOT THE JOINT IS INFECTED. IF PJI IS PRESENT,TRY TO FIND OUT THE CAUSATIVE MICROORGANISM AND ITS ANTIMICROBIAL SUSCEPTIBILITY.

18. ELEVATED ESR AND CRP VALUES BLOOD CULTURE TO IDENTIFY BACTEREMIA PLAIN RADIOGRAPHS : TYPICAL SIGNS OF A SEPTIC PROCESS ON X-RAY FILMS ARE PERIPROSTHETIC OSTEOPOROSIS, PERIOSTEAL REACTION, EROSIONS OF THE ENDOSTEAL PROFILE AND PERIPROSTHETIC OSTEOLYSIS BUT THESE HAVE VERY LOW SENSITIVITY AND THE DIAGNOSIS IS OFTEN DELAYED BY 3–6 MONTHS.

19. ULTRASONOGRAPHY MAY DEMONSTRATE EFFUSIONS AND SYNOVIAL HYPERTROPHY AND DUE TO HIGH SPATIAL RESOLUTION CAN DIFFERENTIATE ABSCESS IN SOFT TISSUES FROM JOINT PATHOLOGIES. ASPIRATION AND TISSUE BIOPSY ARE THE ULTIMATE TOOLS TO ESTABLISH DIAGNOSIS. RADIONUCLIDE IMAGING IS VERY POPULAR AND COMBINED LEUKOCYTE/MARROW IMAGING WITH A REPORTED ACCURACY OF 88–98% BUT IT IS TECHNICALLY COMPLEX AND EXPENSIVE.

20. Bone scan with Tc99m methylendiphosphonate (MDP) is the most common nuclear medicine procedure used but is limited by low specificity especially up to 6 months following surgery.

21. DEFINITE DIAGNOSIS OF PJI CAN BE MADE AS BELOW: 1. A SINUS TRACT COMMUNICATING WITH THE PROSTHESIS OR 2. A PATHOGEN IS ISOLATED BY CULTURE FROM TWO SEPARATE TISSUE OR FLUID SAMPLES OBTAINED FROM THE AFFECTED PROSTHETIC JOINT (AT LEAST 3 AND NO MORE THAN 5 SAMPLES SHOULD BE OBTAINED) OR 3 . FOUR OF THE FOLLOWING SIX CRITERIA EXIST (PROBABLE INFECTION IF <4 CRITERIA MET): A.ELEVATED SERUM ERYTHROCYTE SEDIMENTATION RATE (ESR) >30 MM/1ST HOUR OR SERUM CRP CONCENTRATION >10 MG/L (THESE MARKERS MAY ALSO BE ELEVATED 30–60 DAYS POSTOPERATIVELY)

22. B. ELEVATED SYNOVIAL WHITE BLOOD CELL (WBC) COUNT (>3,000/MM3 ) C. ELEVATED SYNOVIAL NEUTROPHIL PERCENTAGE (>80%) D. PRESENCE OF PURULENCE IN THE AFFECTED JOINT E. ISOLATION OF A MICROORGANISM IN ONE CULTURE OF PERIPROSTHETIC TISSUE OR FLUID (MERE ISOLATION OF LOW VIRULENT PATHOGEN SUCH AS CONS, PROPIONIBACTERIUM ACNES, OR CORYNEBACTERIUM IN THE ABSENCE OF OTHER CRITERIA IS NOT BELIEVED TO REPRESENT A DEFINITE INFECTION. ISOLATION OF A SINGLE VIRULENT ORGANISM SUCH A S. AUREUS MAY REPRESENT A PJI) F. GREATER THAN FIVE NEUTROPHILS PER HIGH-POWER FIELD IN FIVE HIGH POWER FIELDS OBSERVED FROM HISTOLOGIC ANALYSIS OF PERIPROSTHETIC TISSUE AT 400 TIMES MAGNIFICATION.

23. MANAGEMENT GENERAL PRINCIPLES: GOALS OF PJI TREATMENT ARE TO ERADICATE THE INFECTION. RESTORE PAIN FREE FUNCTION OF THE INFECTED JOINT. MINIMIZE PJI RELATED MORBIDITY AND MORTALITY FOR THE PATIENT.

24. DAIR PROCEDURE(DEBRIDEMENT,ANTIBIOTICS AND IMPLANT RETENTION) THE PRIOR SURGICAL INCISION IS OPENED FOLLOWED BY IRRIGATION AND DEBRIDEMENT OF ANY NECROTIC OR INFECTED TISSUE. STABILITY OF THE PROSTHESIS IS ASSESSED INTRAOPERATIVELY, TYPICALLY FOLLOWED BY REMOVAL AND REPLACEMENT OF ANY EXCHANGEABLE COMPONENTS SUCH AS POLYETHYLENE LINER. THE ENTIRE JOINT IS THEN THOROUGHLY IRRIGATED AND CLOSED, TYPICALLY OVER A DRAIN.

25. AFTER PATHOGEN IDENTIFICATION AND ANTIMICROBIAL SUSCEPTIBILITY ARE DEFINED, IV ANTIBIOTICS ARE GIVEN FOR 2-6 WEEKS FOLLOWING DAIR PROCEDURE. DAIR PROCEDURE IS DONE IN SHORT DURATION OF SYMPTOMS (OCCURING WITHIN FIRST MONTH POST OPERATIVELY) OR LATE ACUTE HEMATOGENOUS INFECTIONS(WITH SYMPTOMS <3 WEEKS), A STABLE IMPLANT , AND NO SINUS TRACT. PATIENTS WHO FAIL DAIR PROCEDURE ULTIMATELY UNDERGO A TWO STAGE ARTHROPLASTY EXCHANGE.

26. TWO STAGE ATHROPLASTY EXCHANGE :ALSO REFERRED TO AS A STAGED EXCHANGE, IS CONSIDERED TO BE THE MOST DEFINITIVE STRATEGY IN TERMS OF INFECTION ERADICATION AND PRESERVATION OF JOINT FUNCTION. IDEAL PATIENTS FOR 2-STAGE EXCHANGE STRATEGY ARE PATIENTS WITH CHRONIC INFECTIONS WITH ADEQUATE BONE STOCK, WHO ARE MEDICALLY FI T AND WILLING TO UNDERGO AT LEAST TWO SURGERIES. PATIENTS WITH SINUS TRACTS OR WITH DIFFICULT-TO TREAT ORGANISMS SUCH AS MRSA, ENTEROCOCCI AND CANDIDA SPECIES WOULD ALSO POTENTIALLY QUALIFY FOR THIS PROCEDURE.

27. IN FIRST SURGERY, CULTURES ARE OBTAINED, ALL INFECTED TISSUE IS DEBRIDED AND THE COMPONENTS AND PMMA ARE REMOVED. AN ANTIMICROBIAL IMPREGNATED PMMA SPACER IS IMPLANTED INTO THE JOINT SPACE PRIOR TO CLOSURE TO DELIVER LOCAL ANTIMICROBIAL THERAPY AND MAINTAIN LIMB LENGTH. PATHOGEN DIRECTED IV ANTIBIOTIC THERAPY IS GIVEN FOR 4-6 WEEKS FOLLOWING THE FIRST STAGE. THIS IS THEN FOLLOWED BY AT LEAST 2-6 WEEKS ANTIBIOTIC FREE TIME PERIOD, DURING WHICH THE PATIENT IS EVALUATED FOR ANY SIGNS OF ONGOING INFECTION, TYPICALLY USING INFLAMMATORY MARKERS AND SYNOVIAL FLUID ANALYSIS.

28. IF THERE IS ANY EVIDENCE OF ONGOING INFECTION, A REPEAT DEBRIDEMENT PROCEDURE MAY BE PERFORMED FOLLOWED BY FURTHER ANTMICROBIAL THERAPY BEFORE ATTEMPTED REIMPLANTATION. AT THE TIME OF REIMPLANTATION, BIOPSY SPECIMENS ARE OBTAINED FOR FROZEN SECTION AND PERMANENT HISTOPATHOLOGICAL EXAMINATIONS AND CULTURE. IF THE RESULT IS NEGATIVE THEN NEW PROSTHESIS IS IMPLANTED USING ANTIMICROBIAL LOADED PMMA.

29. ONE-STAGE ARTHROPLASTY EXCHANGE : ALSO REFERRED TO AS DIRECT EXCHANGE PROCEDURE, IS LESS FREQUENTLY PERFORMED THAN TWO-STAGE ARTHROPLASTY EXCHANGE. OPEN ARTHROTOMY AND DEBRIDEMENT ARE PERFORMED FOLLOWED BY COMPLETE REMOVAL OF THE PROSTHESIS AND PMMA. A NEW ARTHROPLASTY IS IMPLANTED DURING THE SAME PROCEDURE, USING ANTIMICROBIAL LOADED PMMA TO FIX NEW ARTHROPLASTY IN PLACE.

30. THE MOST COMMONLY USED ANTIBIOTIC REGIMEN INCLUDES 4 TO 6 WEEKS OF I.V ANTIBIOTICS FOLLOWED BY 3 TO 12 MONTHS OF ORAL ANTIBIOTICS. A RELATIVELY HEALTHY PATIENT WITH ADEQUATE BONE STOCK AND SOFT TISSUES, AND PATIENTS WITH AN EASILY TREATABLE ORGANISM (STREPTOCOCCI OTHER THAN ENTEROCOCCI, METHICILLIN-SENSITIVE STAPHYLOCOCCI, AND NONPSEUDOMONAL GRAM-NEGATIVE ORGANISMS) ARE PREFERRED CANDIDATES FOR 1-STAGE EXCHANGE.

31. AMPUTATION: MAY BE REQUIRED IN SEVERE UNTREATABLE OR UNRESPONDING INFECTIONS OR IN PATIENTS WITH FAILED MULTIPLE SURGERIES AND MUTILATED LIMB.

32. ANTIMICROBIAL TREATMENT ALONE :CONSIDERED ONLY FOR THOSE WHO ARE UNABLE TO UNDERGO EVEN A SINGLE SURGICAL PROCEDURE( eg : DUE TO MULTIPLE COMORBIDITIES)OR ARE UNWILLING TO UNDERGO SURGERY AND WHO HAVE WEEL FIXED PROSTHESIS AND INFECTION WITH MICROORGANISMS THAT ARE SUSCEPTIBLE TO ORAL ANTIBIOTICS.

33. PREVENTION OF PJI IDENTIFICATION AND OPTIMIZATION OF ANY MODIFIABLE RISK FACTORS PRIOR TO JOINT ARTHROPLASTY, FOR EXAMPLE WELL CONTROLLED BLOOD SUGAR LEVELS, NO SITE OF INFECTION, STOP SMOKING. REDUCTION OF SKIN FLORA: RECENT SURGICAL SITE INFECTION GUIDELINES RECOMMEND MUPIROCIN NASAL OINTMENT FOR PATIENTS WITH S.AUREUS COLONIZATION.

34. PERIOPERATIVE ANTIMICROBIAL PROPHYLAXIS: IT HAS SHOWN TO REDUCE THE RISK OF SURGICAL SITE INFECTION BY >80%. LAMINAR AIRFLOW ANTIMICROBIAL LOADED PMMA AT PROSTHESIS IMPLANTATION.

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