Aim. Analysis of microbiological spectrum and resistance patterns as well as the clinical outcome of patients who underwent a Debridement, antibiotics and implant retention (DAIR) procedure in the early phase following failed two-stage exchange arthroplasty of the knee and hip. Method. Of 312 patients treated with two-stage exchange arthroplasty between January 2011 and December 2019, 16 (5.1%) patients (9 knee, 7 hip) underwent a DAIR procedure within 6 months following second stage. We retrospectively analyzed the microbiological results as well as changes in the microbiological spectrum and antibiotic resistance patterns between stages of two-stage exchange arthroplasties and DAIR procedures. Patient's re-revision rates after a minimum follow-up of 12 months following DAIR procedure were evaluated. Moreover, differences between knee and hip and between infected primary total joint replacement (TJRs) and infected revision TJRs as well as patient's host factors and microbiological results regarding the outcome of DAIR were analyzed. Results. In 7/16 (43.8%) patients the first and second stage procedure was culture positive, in 5/16 (31.2%) patients the first and second stage procedure was culture negative and in 4/16 (25%) patients the first stage procedure was culture positive, and the second stage procedure was culture negative. Moreover, 6 (37.5%) out of 16 DAIR procedures showed a positive microbiological result. In 5/7 (71.4%) patients with culture positive second stage procedure a different microorganism compared to first stage procedure was detected. In 6/6 (100%) patients with culture positive DAIR procedure, the isolated microorganisms were not detected during first or second stage procedure. An additional re-revision surgery was necessary in 4/16 (25%) patients after a median time of 31 months (range, 12 to 138 months) at a mean follow up of 63.1 ± 32 months following DAIR procedure. Highest re-revision rates were found in patients with culture positive second stage procedures (3/7 [42.9%]) and patients with culture positive DAIR procedures (2/6 [33.3%]). Conclusions. DAIR procedure seems to be a useful early treatment option following failed two-stage exchange arthroplasty. The re-revision rates were independent of different combinations of culture positive and culture negative first and second stage procedures. The high number of changes in the microbiological spectrum needs to be considered in the treatment of PJI

It is strongly recommended that tissue and synovial fluid culture samples be obtained during reimplantation performed as part of a two-stage exchange arthroplasty. The incidence of positive cultures during reimplantation and the influence of positive cultures on subsequent outcome are unknown. This aim of this study was to determine the incidence of positive cultures during reimplantation and to investigate the association between positive cultures at reimplantation and the subsequent outcome. A retrospective review was conducted on 267 patients that met the Musculoskeletal Infection Society (MSIS) criteria for PJI that completed both stages of two-stage exchange arthroplasty (Table 1). Intraoperative culture results from tissue and/or synovial fluid were obtained. Cultures were positive in 33 cases (12.4%) undergoing reimplantation surgery (Figure 1). Treatment failure was assessed based on the Delphi consensus definition. Logistic regression analysis was performed to assess the predictors of positive culture and risk factors for failure of two-stage exchange arthroplasty. Treatment failure was 45.5% for those with a positive intraoperative culture and 20.9% in those with negative cultures at the time of reimplantation. When controlling for organism virulence, comorbidities, and other confounding factors, treatment failure was higher (odds ratio [OR]: 3.3; 95% confidence interval [CI]: 1.3–4.5) and occurred at an earlier time point (hazard ratio: 2.5; 95% CI: 1.3–4.5) in patients with a positive reimplantation culture. The treatment failure rate was not different between cases with two or more positive cultures (36.4%) and one positive culture (42.8%). Positive intraoperative cultures during reimplantation, regardless of the number of positive samples were independently associated with two times the risk of subsequent infection and earlier treatment failure. Surgeons should be aware that a positive culture at the time of reimplantation independently increases the risk of subsequent failure and needs to be taken seriously. Given the significance of these findings, future studies are needed to evaluate the optimal management of positive cultures during reimplantation surgery

Aim. The purpose of this work is to study whether there is or not, in the case of an aseptic arthroplasty exchange, a relationship between positive cultures and an early periprosthetic joint infection. Method. We carried out a retrospective review of our cases of aseptic exchange arthroplasties of hip, knee and shoulder performed between January 2007 and December 2015. The follow-up period was, in average, from 1 to 9 years, and in all the cases perioperative cultures were evaluated. Results. The number of arthroplasties reviewed was 183, corresponding to 180 patients. Seventy-six cultures were positive for one or more microorganisms. Staphylococcus epidermidis was the microorganism most isolated followed by other Coagulase Negative Staphylococci. Five cases (6.58%) were followed by an acute infection. In three of these cases (60%) the previous culture were positive, but only in one single case, one of the microorganisms isolated after the infection was the same as the isolated previously. Conclusions. Perioperative cultures in aseptic exchange arthroplasties seems not to have any value as infection predictor. Neither the previous isolated microorganisms, in case of postoperative infection, have any value as a predictor of the etiological agent

Purpose. Management and outcomes of fungal periprosthetic joint infection (PJI) remain unclear due to its rarity. Although two-stage exchange arthroplasty is considered a treatment of choice for its chronic features, there is no consensus for local use of antifungal agent at the 1st stage surgery. The purpose of this study was to evaluate the efficacy of antifungal-impregnated cement spacer in two-stage exchange arthroplasty against chronic fungal PJIs after total knee arthroplasty (TKA). Methods. Nine patients who were diagnosed and treated for chronic fungal PJIs after TKA in a single center from January 2001 to December 2016 were enrolled. Two-stage exchange arthroplasty was performed. During the 1st stage resection arthroplasty, amphotericin-impregnated cement spacer was inserted for all patients. Systemic antifungal medication was used during the interval between two stage operations. Patients were followed up for more than 2 years after exchange arthroplasty and their medical records were reviewed. Results. The average duration from the initial symptom to fungal PJI diagnosis was 20 months (range, 5 to 72 months). Average erythrocyte sedimentation rate and C-reactive protein level at diagnosis were 56 mm/h (range, 30 to 89 mm/h) and 2.25 mg/dl (range, 0.11 to 3.97 mg/dl), respectively. Fungal PJI was confirmed by preoperative joint aspiration culture in 6 cases. For the other 3 cases, it was confirmed by open debridement tissue culture. All infections were caused by Candida parapsilosis except for one case which was caused by Candida pelliculosa. The average number of operations before exchange arthroplasty to solve the infection was 2.7 times (range, 1 to 5 times). Average duration of antifungal agent use confirmed by sensitivity test was 7 months (range, 4 to 15 months). Mean interval between two stage operation was 6 months (range, 1.5 to 15 months). After two-stage exchange arthroplasty, no patient had recurrent fungal infection during a mean follow-up of 66 months (range, 24 to 144 months). Conclusions. Due to its ill-defined symptoms and inconclusive blood test, fungal PJI after TKA is difficult to diagnose and has a prolonged clinical course. Two-stage exchange arthroplasty with antifungal-impregnated cement spacer is a very effective strategy with excellent outcome

The method of choice in the management of chronic infections is the exchange arthroplasty. The exchange arthroplasty can be performed either in a one- or in a two-stage setting, whereas the two-stage exchange arthroplasty is still considered the “gold standard” worldwide. The current literature and guidelines for PJI treatment deliver no clear evidence that a two-stage exchange procedure has a clearly higher success rate than the one-stage procedure. Since the first implantation of mixing antibiotics into bone cement in 1970s, the ENDO-Klinik followed until today in over 85% of all infected cases the one-stage exchange arthroplasty for the management of PJI. The main requirement is the known germ with known susceptibility based on microbiological diagnostics. Proper bone stock for cemented, in some cases, uncemented reconstruction, and the possibility of primary wound closure are also clear assumptions. The one-stage exchange arthroplasty delivers diverse advantages. For instance, the need for only one operation, shorter hospitalization, reduced systemic antibiotics and lower overall cost. A well-defined pre-operative planning regime is absolutely mandatory

Aim. Periprosthetic joint infection (PJI) is a devastating complication that develops after total joint arthroplasty (TJA) whose incidence is expected to increase over the years. Traditionally, surgical treatment of PJI has been based on algorithms, where early infections are preferably treated with debridement, antibiotics, and implant retention (DAIR), while late infections with two-stage revision surgery. Two-stage revision is considered the “gold standard” for treatment of chronic PJI. In this observational retrospective study, we investigated the potential role of inflammatory blood markers (neutrophil-to- lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), systemic inflammatory index (SII)], systemic inflammatory response index (SIRI), and aggregate index of systemic inflammation (AISI)) as prognostic factors in two-stage exchange arthroplasty for PJI. Method. A single-center retrospective analysis was conducted, collecting clinical data and laboratory parameters from patients submitted to prosthetic explantation for chronic PJI. Laboratory parameters (PCR, NLR, MLR, PLR, SIRI, SII and AISI) were evaluated at the explantation time, at 4, 6, 8 weeks after surgery and at reimplantation time. Correlation between laboratory parameters and surgery success was evaluated, defined as infection absence/resolution at the last follow up. Results. 57 patients with PJI were evaluated (62% males; average age 70 years, SD 12.14). Fifty-three patients with chronic PJI were included. Nineteen patients completed the two-stage revision process. Among them, none showed signs of re-infection or persistence of infection at the last available follow up. The other twenty-three patients did not replant due to persistent infection: among them, some (the most) underwent spacer retention; others were submitted to Girdlestone technique or chronic suppressive antibiotic therapy. Of the patients who concluded the two-stage revision, the ones with high SIRI values (mean 3.08 SD 1.7, p-value 0.04) and MLR values (mean 0.4 SD 0.2, p-value 0.02) at the explantation time were associated with a higher probability of infection resolution. Moreover, higher variation of SIRI and PCR, also defined respectively delta-SIRI (mean −2.3 SD 1.8, p-value 0.03) and delta-PCR (mean −46 SD 35.7, p-value 0.03), were associated with favorable outcomes. Conclusions. The results of our study suggest that, in patients with PJI undergoing two-stage, SIRI and MLR values and delta-SIRI and delta-PCR values could be predictive of favorable outcome. The evaluation of these laboratory indices, especially their determination at 4 weeks after removal, could therefore help to determine which patients could be successfully replanted and to identify the best time to replant

Historical perspective: Irrigation and debridement (I&D) with modular exchange has historically been the recommended treatment for acute post-operative periprosthetic joint infection (PJI), and acute hematogenous PJI. The theory supporting this practice was that because the bacterial glycocalyx had not yet formed by these early time points, by simply debriding the intra-articular bacterial load and exchanging the modular parts, one could potentially eradicate the infection, retain the prior components, and minimise morbidity to the patient. More recently, literature is coming out suggesting that this may not necessarily be the case. The vast majority of published research on the outcomes following I&D for treatment of PJI has focused on either cohorts of total knee arthroplasty patients or combined cohorts of total hip and knee patients. For this reason, it is difficult to tease out the differential success rate of periprosthetic hip vs. knee infections. Sherrell et al. performed a systematic review of the existing literature and created a table detailing the failure rates for various published articles on I&D for periprosthetic TKA infection. Since it is the glycocalyx that has been thought to be the reason for treatment failure of many cases of PJI treated with I&D, many authors have implicated staphylococcal species as a predictor of a negative outcome with failure rates ranging from 30–35%. Methicillin resistant organisms have been shown to be particularly difficult to eradicate with an isolated I&D, with a 72–84% failure rate at 2 year follow-up. Interestingly, a recent study by Odum et al. suggests that neither the infecting microbe, nor the antibiotic resistance profile of the organism, as has been classically thought, actually predicts success of I&D. Previous reports have indicated that the ability of I&D to control infection is related to the duration of symptoms and its timing relative to the index surgery. However, more recent literature is coming out to support the contrary. Koyonos et al. reviewed the outcomes of a series of 138 cases of PJI treated with I&D based on acuity of infection and concluded that an I&D has a limited role in controlling PJI regardless of acuity. Intuitively, the physical health of the host/patient should influence the success of I&D for treatment of PJI. Several authors have shown that an immunocompromised state is a predictor of treatment failure. Furthermore, Azzam et al. reported that patients with a higher American Society of Anesthesia (ASA) score, a proxy of severity of medical comorbidities, had a significantly higher failure rate. Although potentially appealing due to relative ease of execution and minimal surgical morbidity, the ability to successfully eradicate infection with an arthroscopic procedure may be compromised. Given the inability to perform a radical surgical debridement, nor exchange modular components, arthroscopic debridement should be used with extreme reservation in any case of PJI, regardless of the host, nature of the infecting organism, or acuity of infection. I&D as a conservative, less morbid alternative to two-stage exchange - There is a growing body of literature to suggest that an I&D with modular component exchange may not be the benign, less morbid alternative to the ‘gold standard’ two-stage exchange arthroplasty. In fact, Fehring et al. has reported that the success of a two-stage antibiotic spacer exchange arthroplasty may be compromised by an initial I&D. They found that patients who were initially treated with an I&D only had a 66% chance of eradicating infection following a two-stage exchange arthroplasty, in contrast to historical reports of 80–90% success

Aim. Treatment of chronic prosthetic joint infection (PJI) combines exchange arthroplasty and effective antibiotic therapy. Staphylococci are the most frequent microorganism isolated in PJIs, with resistance to methicillin found in 15–50% of the cases. Data from randomized trials on treatment of methicillin-resistant staphylococci are lacking and the choice of antibiotic(s) and recommendations vary according to authors. To date, combination therapy including vancomycin is the treatment of choice. Minocycline, a cyclin antibiotic, is naturally effective against methicillin-resistant staphylococci. We use this antibiotic since many years in combination with vancomycin for the treatment of multi-drug resistant staphylococcal bone and joint infections. The aim of this study is to analyze the outcome of patients treated with combination antibiotic therapy including minocycline for the treatment of chronic methicillin-resistant staphylococcal PJI. Method. We conducted a cohort study between 2004 and 2014 in our referral center for bone and joint infections. Data were extracted from the prospective database. All the patients receiving an initial combination therapy including at least 4 weeks of minocycline, given orally, and another IV antibiotic, usually high-dose continuous IV vancomycin, for chronic MR staphylococcal PJI and who underwent one or two stage exchange arthroplasty, were included. They were followed prospectively for at least 2 years. Results. We included 42 patients: 26 patients (62%) had one-stage, 16 patients (38%) had two stage exchange arthroplasty. Median duration of IV and total antibiotic therapy was 42 [40–44] days and 84 [84–88] days, respectively. 41 patients (98%) received vancomycin as associated initial therapy. Thirty-six patients received 100mgx3 per day of minocycline. Six received >300mg per day because of low serum concentrations. Median follow-up was 48 months (IQR 27–58). Survival rate without infection was 84,5% at 2 years, 70.2% at 6 years. Four patients reported adverse events due to minocycline: one had grade 4 thrombopenia leading to minocycline withdrawal, two had grade 2 liver toxicity. One patient had grade 1 nauseas. Two patients with MR Staphylococcus epidermidis knee arthroplasty experienced relapse. Three patients with hip arthroplasty infection developed a new infection within 2 year due to MSSA, Pseudomonas aeruginosa, and plurimicrobial for the last one. Three further patients developed a new infection 3 (n=2) and 4 years later. They were all acute haematogenous infections. Conclusions. Our data support the use of minocycline combination therapy with high-dose IV vancomycin for the treatment of chronic PJI due to methicillin-resistant Staphylococci

Aim. Surgical management of PJI remains challenging with patients failing treatment despite the best efforts. An important question is whether these later failures reflect reinfection or the persistence of infection. Proponents of reinfection believe hosts are vulnerable to developing infection and new organisms emerge. The alternative hypothesis is that later failure is a result of an organism that was present in the joint but was not picked up by initial culture or was not a pathogen initially but became so under antibiotic pressure. This multicenter study explores the above dilemma. Utilizing next-generation sequencing (NGS), we hypothesize that failures after two-stage exchange arthroplasty can be caused by an organism that was present at the time of initial surgery but not isolated by culture. Method. This prospective study involving 15 institutions collected samples from 635 revision total hip(n=310) and knee(n=325) arthroplasties. Synovial fluid, tissue and swabs were obtained intraoperatively for NGS analysis. Patients were classified per 2018 Consensus definition of PJI. Treatment failure was defined as reoperation for infection that yielded positive cultures, during minimum 1-year follow-up. Concordance of the infecting pathogen cultured at failure with NGS analysis at initial revision was determined. Results. Among the total cohort, 203 revisions were considered infected and 432 were aseptic (based on ICM-criteria). Of the infected cases, 157 were NGS-positive and 46 NGS-negative. Twenty-nine ICM-positive patients (29/157;18.5%) failed by reoperation with an organism confirmed on culture. In 23 of these (23/29;79.3%), the organism at failure was present on NGS at initial revision. The remaining 6 cases detected discordant organisms between initial NGS and culture at failure. Of the 432 ICM-negative patients, NGS identified microbes in 48.1% (208/432) of “aseptic” revisions, and 17 of these failed. Thirteen of the 17 failures (76.5%) were due to an organism previously detected by NGS at initial revision. Conclusion. Our collaborative findings suggest that most failures (79.3%) by infection recurrence could be attributed to an organism previously detected by NGS at index revision surgery

Aim. Debridement, antibiotic, and implant retention (DAIR) is an accepted treatment of early and late acute Total Knee Arthroplasty (TKA) infections. DAIR failure may adversely affect the outcome of a subsequent two-stage exchange arthroplasty. Controversy exists on risk factors that can affect DAIR's results. The aim of the study is to review presurgical, intrasurgical and postsurgical variables that could affect DAIR's result. Method. A retrospective study of 27 DAIRs performed between 2015–2019 to treat late acute TKA infections was carried out. Patients were divided into two groups depending on DAIR's outcome [Healing (H) vs non-healing group (NH)] according on the Delphi-based multidisciplinary consensus criteria on success after treatment of periprosthetic joint infection. We reviewed presurgical variables, including epidemiological variables (Age, Sex, comorbidities, ASA, Charlson, BMI, alcohol dependency), prosthesis variables (prosthesis type, primary cause of operation, primary TKA surgery center), infection variables (concomitant infection, previous antibiotic treatment, c-reactive protein, synovial WBC count, synovial % PMN, pathogen), KLIC score and CRIME 80 score. Surgical variables such as surgery duration and type of surgery (elective vs urgent). Post-surgical variables like antibiotic treatment duration and destination at discharge. Normal distribution was assessed by Shapiro-Wilk test. Mann Whitney U test was used to compare the two independent sample variables. Chi-squared test was used for qualitative variables. P-value was established at 0.05 and statistical power at 80%. Results. Infection Healing was achieved in 63% of patients. In presurgical variables, alcohol dependency, hypertension, liver disease, previous surgery performed in another institution were more frequent in NH group (p< 0.05). KLIC score value equal or greater than 4 had a higher risk of surgical failure (p < 0.05). Regarding surgical variables, the healing group had more negative cultures than de non-healing one (p<0.05). Regarding post-surgical variables, long term antibiotic treatment (six months) achieved more healing after DAIR (p<0.05). Conclusions. Alcohol dependency, hypertension, liver disease and KLIC score values equal or greater than 4, may increases the risk of DAIR failure. Finally, we observed that the long-term antibiotic treatment (6 months) favors healing after DAIR

Background. Fungal infection at an arthroplasty site is rare and poses a therapeutic challenge. To the best of our knowledge, no reports have been published thus far on the success rate of prosthesis reimplantation after fungal prosthetic joint infections. Questions/purposes. We asked: (1) What is the success rate in terms of infection eradication using a two-stage exchange arthroplasty in patients with hip or knee fungal periprosthetic joint infections, particularly focusing on Candida infections? (2) What patient-, infection-, and treatment-related variables are associated with the success or failure of treatment?. Methods. From January 2000 to December 2010, 16 patients with hip or knee candidal periprosthetic joint infections were treated with two-stage exchange arthroplasty at our institute. Treatment success was defined as a well-functioning joint without relapse of candidal infection after prosthesis reimplantation, while treatment failure was defined as uncontrolled or a relapse of candidal infection or mortality. Variables, including age, sex, comorbidities, microbiology, antimicrobial agents used, and operative methods, were analyzed. Minimum followup was 28 months (mean, 41 months; range, 28–90 months). Results. At latest followup, the treatment failed to eradicate the infection in eight of the 16 patients, and there were four deaths related to fungemia. Four patients required permanent resection arthroplasty owing to uncontrolled or recurrent candidal infections. All eight patients (50% successful rate) who had their infections eradicated and successful prosthesis reimplantation had prolonged treatment with oral fluconazole before (mean, 8 months) and after (mean, 2.2 months) prosthesis reimplantation. The antifungal therapy correlated with successful treatment. Renal insufficiency, hypoalbuminemia, anemia, and chronic obstructive pulmonary disease were significantly more prevalent in the treatment-failure group than in the treatment-success group. Conclusions. Half of the patients treated with two-stage exchange arthroplasty for fungal periprosthetic joint infections had recurrence or lack of control of the infection. A prolonged antifungal therapy appeared to be essential for successful treatment of candidal periprosthetic joint infections. The presence of renal insufficiency, hypoalbuminemia, anemia, or chronic obstructive pulmonary disease might be associated with a poor outcome

The infected shoulder arthroplasty is a devastating complication that can be very difficult to diagnose and treat. This presentation will compare the data on two-stage and single-stage exchange arthroplasty as pertains to functional outcomes and efficacy of eradication of the infection. Traditionally, the two-stage exchange arthroplasty has been the gold standard in the United States for the treatment of infected total shoulder replacements. In Europe, the trend seems to be moving towards a single-stage exchange with results that are reportedly comparable for eradication of infection to those of two-stage exchange although with seemingly better results for shoulder function. The surgeon's clinical experience with both techniques will be highlighted. A lively debate of the virtues and pitfalls of both approaches is the goal

The best surgical modality for treating chronic periprosthetic shoulder infections has not been established, with a lack of randomised comparative studies. This systematic review compares the infection eradication rate and functional outcomes after single- or two-stage shoulder exchange arthroplasty, to permanent spacer implant or resection arthroplasty. Full-text papers and those with an abstract in English published from January 2000 to June 2014, identified through international databases, were reviewed. Those reporting the success rate of infection eradication after a single-stage exchange, two-stage exchange, resection arthroplasty or permanent spacer implant were included, with a minimum follow-up of 6 months and sample size of 5 patients. Eight original articles reporting the results after resection arthroplasty (n = 83), 6 on single-stage exchange (n = 75), 13 on two-stage exchange (n = 142) and 8 papers on permanent spacer (n = 68) were included. The average infection eradication rate was 86.7% at a mean follow-up of 39.8 months (SD 20.8) after resection arthroplasty, 94.7% at 46.8 months (SD 17.6) after a single-stage exchange, 90.8% at 37.9 months (SD 12.8) after two-stage exchange, and 95.6% at 31.0 months (SD 9.8) following a permanent spacer implant. The difference was not statistically significant. Regarding functional outcome, patients treated with single-stage exchange had statistically significant better postoperative Constant scores (mean 51, SD 13) than patients undergoing a two-stage exchange (mean 44, SD 9), resection arthroplasty (mean 32, SD 7) or a permanent spacer implant (mean 31, SD 9) (p=0.029). However, when considering studies comparing pre- and post-operative Constant scores, the difference was not statistically significant. This systematic review failed to demonstrate a clear difference in infection eradication and functional improvement between all four treatment modalities for established periprosthetic shoulder infection. The relatively low number of patients and the methodological limitations of the studies available point out the need for well designed multi-center trials to further assess the best treatment option of peri-prosthetic shoulder infection

Aim. A two-stage exchange of an infected prosthetic joint (PJI) is considered the most effective surgical treatment of chronic PJIs, particularly in North America. However, reinfection rates are unacceptably high (10–20%). This could be the consequence of a persistent infection or a new infection introduced during the first or second stage of the exchange arthroplasty. We aimed to determine: i) the prevalence of positive cultures at reimplantation, ii) whether there is an association between positive cultures at reimplantation and reinfection during follow-up, and iii) if there is a microbiological correlation between primary infections, reimplantations and reinfections. Method. We retrospectively evaluated all two-stage exchange procedures performed at two academic centers between 2000 and 2015. Primary culture-negative PJIs and cases in whom no intraoperative cultures were obtained during reimplantation were excluded from the analysis. One or more positive intraoperative cultures during reimplantation were considered positive for infection. Reinfection was defined as the need for additional surgical intervention after reimplantation or the need for antibiotic suppressive therapy due to persistent clinical signs of infection. Results. A total of 424 cases were included in the final analysis with a mean follow-up of 48 months (SD 37). Eighty-eight cases (20.8%) had positive cultures during reimplantation (second stage) of which 68.1% (n=60) grew a different microorganism than during the first stage of the procedure. The percentage of positive cultures during reimplantation was higher for hips than for knees (26.5% vs 17.1%, p 0.02). For the total group, the reinfection rate during follow-up was 18.4% (78/424), which was 29.5% for the positive-culture group versus 15.5% for the culture-negative group at reimplantation (p=0.002). A positive culture during reimplantation was an independent risk factor for reinfection during follow-up in the multivariate analysis (OR 2.2 (95% CI 1.2 – 3.8), p 0.007). Reinfection was caused by a different microorganism than the primary infection (first stage) in 64.1% of cases (50/78). Conclusions. There is a very high rate of positive cultures at reimplantation, which are mostly attributed to a different microorganism than the primary infection and is associated with a worse outcome. These results stress the importance of developing treatment strategies for this particular population

Periprosthetic joint infection (PJI) is a major complication affecting >1% of all total knee arthroplasties, with compromise in patient function and high rates of morbidity and mortality. There are also major socioeconomic implications. Diagnosis is based on a combination of clinical features, laboratory tests (including serum and articular samples) and diagnostic imaging. Once confirmed, prompt management is required to prevent propagation of the infection and further local damage. Non-operative measures include patient resuscitation, systemic antibiotics, and wound management, but operative intervention is usually required. Definitive surgical management requires open irrigation and debridement of the operative site, with or without exchange arthroplasty in either a single or two-stage approach. In all options, the patient's fitness, comorbidities and willingness for further surgery should be considered, and full intended benefits and complications openly discussed. Late infection almost invariably leads to implant removal but early infections and acute haematogenous infections can be managed with implant retention – the challenge is to retain the original implant, having eradicated infection and restored full function. Debridement with component retention: Open debridement is indicated for acute postoperative infections or acute haematogenous infections with previously well-functioning joints. To proceed with this management option the following criteria must be met: short duration of symptoms - ideally less than 2–3 weeks but up to 6; well-fixed and well-positioned prostheses; healthy surrounding soft tissues. Open debridement is therefore not an appropriate course of management if symptoms have been prolonged – greater than 6 weeks, if there is a poor soft tissue envelope and scarring, or if a revision arthroplasty would be more appropriate due to loosening or malposition of the implant. It is well documented in the literature that there is an inverse relationship between the duration of symptoms and the success of a debridement. It is thought that as the duration of symptoms increases, other factors such as patient comorbidities, soft tissue status and organism virulence play an increasingly important role in determining the outcome. There is a caveat. Based on our learning in the hip, when we see an acute infection where periprosthetic implants are used, it is much easier to use this time-limited opportunity to remove the implants and the associated biofilm and do a single-stage revision instead of just doing a debridement and a change of insert. This will clearly be experience and prosthesis-dependent but if the cementless implant is easy to remove, then it should be explanted. One critical aspect of this procedure is to use one set of instruments and drapes for the debridement and to then implant the new mobile parts and close using fresh drapes and clean instruments. Units that have gained expertise in single-stage revision will find this easier to do. After a debridement, irrigation, and change of insert, patients continue on intravenous antibiotics until appropriate cultures are available. Our multidisciplinary team and infectious disease experts then take over and will dictate antibiotic therapy thereafter. This is typically continued for a minimum of three months. Patients are monitored clinically, serologically, and particularly in relation to nutritional markers and general wellbeing. Antibiotics are stopped when the patients reach a stable level and are well in themselves. All patients are advised to re-present if they have an increase in pain or they feel unwell

Failure of a two-stage exchange arthroplasty for management of periprosthetic joint infection (PJI) poses a major clinical challenge. There is a paucity of information regarding the outcome of further surgical intervention in these patients. Thus, we aim to report the clinical outcomes of subsequent surgical intervention following a failed prior two-stage exchange. Our institutional database was used to identify 60 patients (42 knees and 18 hips) with a failed prior two-stage exchange from infection, who underwent further surgical intervention between 1998 and 2012 and had a minimum of two years follow-up. A retrospective review was performed to extract relevant clinical information, such as mortality, microbiology, and subsequent surgeries. Musculoskeletal Infection Society criteria were used to define PJI, and treatment success was defined using the Delphi criteria as previously reported. Irrigation and debridement (I&D) was performed after a failed two-stage exchange in 61.7% (37/60) patients. The failure rate of I&D in this cohort was 51.3% (19/37). Two patients underwent amputation after I&D due to uncontrolled infection. A total of 40 patients underwent an intended a second two-stage exchange. Reimplantation occurred in only 65% of cases (26/40), and infection was controlled in 61.6% (16/26) of patients. An interim spacer exchange was required in 15% (6/40) of the cases. Of the 14 cases that did not undergo a second stage reimplantation, 5 required amputation, 6 had retained spacers, 1 underwent arthrodesis, and 2 patients died. Further surgical intervention after a failed prior two-stage exchange has poor outcomes. I&D has a high failure rate and many of the patients who are deemed candidates for a second two-stage exchange either do not undergo reimplantation for various reasons or fail after reimplantation. The management of PJI clearly remains imperfect, and there is a dire need for further innovations that may improve the care of these PJI patients

The burden of periprosthetic joint infection (PJI) continues to rise and the management of this dreaded complication continues to pose challenges to the orthopaedic community. Dr Buchholz from the Endo Klinik has been credited for reporting the initial observation that addition of antibiotic to polymethylmethacrylate (PMMA) cement lead to better ability to deliver higher concentrations of antibiotic to the joint milieu and avoid administration of high doses of systemic antibiotics with potential for systemic toxicity. Addition of antibiotics to PMMA cement has continued to be an important aspect of managing patients with chronic PJI. The rationale for this practice is that higher doses of local antibiotics can be reached without placing the patients at risk of systemic toxicity. Whether a one-stage or a two-stage exchange arthroplasty is being performed, antibiotics that can withstand the exothermic reaction of PMMA and are able to elude from cement are added at various doses to the PMMA for later delivery. Although this practice continues to be almost universal, there are a few unknowns. First of all, a recent study raised a valid question regarding this practice. Though intuitively logical, addition of antibiotics to PMMA spacers has not been scrutinised by any level 1 study and hence one is not able to prove that this practice does indeed accomplish its intended objectives of reducing recurrence or persistence of infection. Orthopaedic community is advised to seek avenues to generate this much-needed evidence. The other main unknown is how much, and in some instances which antibiotic, needs to be added to the PMMA cement. Some authorities have declared that antibiotics can be added at high doses, with an average total dose of 10.5 g of vancomycin (range, 3–16 g) and 12.5 g of gentamicin (range, 3.6–19.2 g) in one study, to PMMA cement without the fear of systemic toxicity. In recent years, renal toxicity and other systemic adverse effects have been attributed to addition of high doses of antibiotics to cement. I have personally witnessed such adverse reactions in a few patients. Although initially I was inclined to “blame” the concurrent administration of systemic antibiotics for the renal toxicity that patients developed following insertion of spacer, selective nephrotoxicity (i.e. reaction to aminoglycoside that was only present in the spacer and not systemically administered) and resolution of the nephrotoxicity upon removal of antibiotic spacer, convinced me that our nephrology colleagues have a valid reason to be concerned about addition of high doses of antibiotics to PMMA spacers. What has become clear is that high viscosity cements containing MA-MMA copolymers have been shown to have better antibiotic elution profiles than other PMMA formulations. So when fashioning a spacer in the operating room the surgeon needs to be aware of the differences in elution profile of antibiotics from PMMA and individualise the dose of antibiotics being added to spacer based on the type and viscosity of cement being used and the renal status of the patient. Thus, systemic toxicity caused by addition of antibiotics to cement spacer appears to be a real issue in some circumstances and this needs to be born in mind when managing patients with PJI. There are numerous other issues related to the use of antibiotic cement spacers. In the hip, the lack of adequate offset and limited portfolio of products result in laxity in the soft tissue and subsequent dislocation of the hip. In addition, the dose and type of antibiotic in the premanufactured spacers, at least in the US, are inadequate to lead to a substantial delivery of antibiotics in the local tissues. Because of these issues, I prefer to fabricate “customised” spacers for each patient that I operate on

Introduction. Arthrodesis is usually offered to patients in whom a two stage exchange arthroplasty has already failed or is likely to fail because of local factors (such as soft tissue damage, bone loss or poor perfusion), or because of systemic conditions which categorise the patient as a C-host (e.g. immune deficiency, diabetes and malnutrition). In other words arthrodesis is selected for patients with the worst prognosis. Method. I use an intramedullary nail extending from trochanter to just above the ankle which is locked distally only. The nail is curved with an arc of a 2 meter radius. This conforms to the shape of the femur and when passed through to the straight tibia it ends against the posterior cortex of the distal tibia where the bone is thickest. It creates an angle of between 9° and 11° of flexion at the knee. The nail is bent into 5° of valgus at the point where the femur and tibia meet. This allows the two bones to coapt, dynamise and unite. The procedure is performed in two stages. At the first every effort is made to eradicate the infection by debridement and appropriate local and systemic antibiotics. The nail is inserted at the second procedure and again every effort is made to deal with infection. If infection persists one can easily remove the nail when the knee has fused, and repeat the attempt to eradicate the infection in better circumstances. I have devised a scoring system in order to evaluate the eradication of infection based on clinical grounds, laboratory investigations and radiological examination. This allows for the fact that cure of an infection is not based on any one parameter. Results. I have performed such an arthrodesis in 99 patients. Fusion occurred in 74% of those who had more than six months follow-up. The affected limb was shortened on average by 4 cm. After nailing, pain was relieved in 80% of patients using a sliding scale. Using the scoring system, 31% were definitely cured of infection, 34.5% were intermediate and 34.5% definitely failed. 29 patients had their nail removed and the infection was re-addressed. Using the same evaluation system 12 (24%) were definitely cured, 12 (24%) had a probable cure and 5 (18%) remained infected. This gives an overall eradication of infection of 84%. In 4 patients apparent union of the knee broke down resulting in a jog of movement at the knee. Three of these patients were made comfortable with a gaiter to support the knee. One had his knee re-fixed with a long intramedullary nail. Three nails fractured in situ. In one of these patients the nail had locking screws proximally and distally which prevented dynamisation and union. In the other two non-union was apparent and the nail sustained a fatigue fracture. NO DISCLOSURES

Introduction. 47 yrs male patient had a prior history. 2005 Fx. proximal tibia (open Fx.). 2007 Metal removal. 2008 Arthroscopic debridement (2 times). He visited out hospital with severe pain and tenderness X-ray (Fig 1) and MRI (Fig 2) findings as follows. Conclusively, He had a chorinic osteomylitis of proximal tibia with soft tissue absess. 1st Surgery. I did arthroscopic debridement Arthroscopic finding shows synovitis, meniscus tear and chondromalacia. I did meticulous debridement (irrigation & curettage). 2nd Surgery. He did primary total knee arthro-plasty instead of two-stage exchange arthroplasty in may, 2010 at the another hospital. 3rd Surgery. After 7 months since he had did total knee arthroplasty, he visited to my hospital again with sudden onset of painful swelling & heating sensation. 4th Surgery. I did second stage reimplantation for infected total Knee arthroplasty after 7 weeks. Now he got a pain relief & ROM restroration. Results. Follow up 12 months X-ray showing all implants to be well-positioned and stable. Clinically, there was no implant considered to be loose. In this study, the knee society and functional scores at final follow up were 82 and 68. Conclusion. The infection after sequales of open proximal tibia fracture is treated by two-stage exchange total knee arthroplasty instead of primary total knee arthroplasty. Two-stage reimplantation of an infected total knee arthroplasty using a static antibiotic-cement spacer achieved an infection control and improvement in the clinical result 3). We use an antibiotic-loaded cement spacer(ALACS) preserved knee function between stages, resulting in effective treatment of infection, facilitation of reimplantation, and improved patient satisfaction 1). The principle surgical technique used for two-stage revision of infected total knee including: (1) exposure, (2) implant removal and debridement, and (3) construction of both static and mobile antibiotic spacers 2

Prosthetic joint infection (PJI) remains a devastating complication of arthroplasty. There is significant heterogeneity in treatment approaches to these infections and information on their efficacy relies on single-centre studies. This is the first multi-centre study examining current treatment approaches to patients with PJI. A retrospective cohort study was conducted over a 3-year period (January 2006 – December 2008) involving 10 hospitals in Victoria, Australia. Cases of prosthetic joint infections of hips and knees were identified using an established statewide nosocomial infection surveillance network. Individual medical records were accessed to describe the management and record the outcomes of these patients. Interim analysis from seven hospitals revealed 121 patients with PJI. Staphylococcus aureus was isolated in half of the infections with equal representation of methicillin resistant and methicillin sensitive strains. Debridement and retention (DR) was the most common treatment modality (72%), followed by resection arthroplasty without reimplantation (10%), superficial debridement and antibiotics (9%), one-stage exchange (6%) and two-stage exchange arthroplasty (3%). The timing and number of surgical interventions was however highly variable. The majority of patients underwent arthrotomy with an average of 3 debridements of the infected joint (range 0–10, standard deviation 1.7). Two-thirds of the patients with staphylococcal infections received a rifampicin-containing regimen. The course of oral antibiotic therapy was prolonged with a median duration of 132 days (interquartile range 13–357) but ranged from no oral antibiotic therapy to 1032 days. Overall 72% of patients remained infection-free after a mean follow-up of 15 months, however there was marked variation in outcomes between hospitals with success ranging from 50%-95%. This multi-centre study demonstrates that there is a wide spectrum of treatment approaches to PJI. In addition, DR is the favoured treatment modality, which differs to our European and Northern American counterparts. This study reports real-life management and outcomes from patients at several centres, including many that do not have dedicated research interest in PJI