Outcome Of Prosthetic Joint Infections Research Articles

Acute Prosthetic Joint Infections with Poor Outcome Caused by Staphylococcus Aureus Strains Producing the Panton-Valentine Leukocidin.

The aim of this study was to investigate whether the presence of Staphylococcus aureus (SA) producing the Panton-Valentine leukocidin (PVL) affects the outcome of Prosthetic Joint Infection (PJI). Patients with acute and chronic PJI sustained by SA were prospectively enrolled at the orthopedic unit of "Casa di Cura Santa Maria Maddalena", from January 2019 to October 2021. PJI diagnosis was reached according to the diagnostic criteria of the International Consensus Meeting on PJI of Philadelphia. Synovial fluid obtained via joint aspirations was collected in order to isolate SA. The detection of PVL was performed via real-time quantitative PCR (RT-qPCR). The outcome assessment was performed using the criteria of the Delphi-based International Multidisciplinary Consensus. Twelve cases of PJI caused by SA were included. Nine (75%) cases were acute PJI treated using debridement, antibiotic and implant retention (DAIR); the remaining three (25%) were chronic PJI treated using two-stage (n = 2) and one-stage revision (n = 1), respectively. The SA strains that tested positive for PVL genes were 5/12 (41.6%,). Treatment failure was documented in three cases of acute PJI treated using DAIR, all supported by SA-PVL strains (p < 0.045). The remaining two cases were chronic PJI treated with a revision arthroplasty (one and two stage, respectively), with a 100% eradication rate in a medium follow-up of 24 months. Although a small case series, our study showed a 100% failure rate in acute PJI, probably caused by SA PVL-producing strains treated conservatively (p < 0.04). In this setting, toxin research should guide radical surgical treatment and targeted antibiotic therapy.

Genomic characterization and outcome of prosthetic joint infections caused by Staphylococcus aureus

Staphylococcus aureus is a commensal colonizing the skin and mucous membranes. It can also act as a pathogen, and is the most common microorganism isolated from prosthetic joint infections (PJIs). The aim of this study was to explore the genomic relatedness between commensal and PJI S. aureus strains as well as microbial traits and host-related risk factors for treatment failure. Whole-genome sequencing (WGS) was performed on S. aureus isolates obtained from PJIs (n = 100) and control isolates from nares (n = 101). Corresponding clinical data for the PJI patients were extracted from medical records. No PJI-specific clusters were found in the WGS phylogeny, and the distribution of the various clonal complexes and prevalence of virulence genes among isolates from PJIs and nares was almost equal. Isolates from patients with treatment success and failure were genetically very similar, while the presence of an antibiotic-resistant phenotype and the use of non-biofilm-active antimicrobial treatment were both associated with failure.In conclusion, commensal and PJI isolates of S. aureus in arthroplasty patients were genetically indistinguishable, suggesting that commensal S. aureus clones are capable of causing PJIs. Furthermore, no association between genetic traits and outcome could be demonstrated, stressing the importance of patient-related factors in the treatment of S. aureus PJIs.

399. Treatment and Outcome of Prosthetic Joint Infection in Unicompartmental Knee Arthroplasty

BackgroundUnicompartmental knee arthroplasty (UKA) is an increasingly popular alternative to total knee replacement due to easier recovery and greater satisfaction. However, limited evidence guides the management of periprosthetic joint infection (PJI) in UKA specifically. We retrospectively reviewed the largest cohort of UKA PJI to date, providing our experience in a high volume tertiary institution.MethodsAn institutional PJI database was queried from 2008 to 2016 to identify all PJI cases with an index procedure of UKA. Treatment, diagnostic criteria, Charlson Comorbidity Index (CCI) and microbiology data were collected. Success was defined as no further surgical treatment for infection at 2 years. A chi-square test or Fisher’s exact test was used for comparisons between treatment success and failure groups. Survival probability was calculated using the Kaplan–Meier method.ResultsA total of 24 UKA PJIs were identified with 22 meeting MSIS criteria. Median age at infection was 65.9 years (range, 50.8–87.4), median BMI was 26.7 kg/m2 (range, 21.2–49.5), 75% male (18/24).The average follow-up time was 2.83 years. 9 patients presented with early (4 weeks of symptoms). 63% (15/24) of PJI cases were staphylococcal and 8.3% (2/24) were culture negative. Patients were either treated with 1 stage exchange (n = 3, 100% success), two-stage exchange (n = 5, 80% success) or implant retention (n = 16, 75% success). Overall survivorship was 79% at 2 years (95% confidence interval [CI], 63%–95%). Overall there was no significant association between success and CCI (P = 0.46), infection type (P = 0.29), surgical therapy (P = 0.62), and microorganism (P = 0.05).ConclusionIn this series, UKA PJIs tended to present more often as early post-operative or hematogenous infections. We observed no significant benefit with revision surgery and therefore conclude that implant retention should be considered as first-line surgical treatment. Outcomes of UKA PJI appear comparable to those in TKA PJIs.Disclosures All authors: No reported disclosures.

Infection after Constrained Condylar Knee Arthroplasty: Incidence and microbiological findings in 100 consecutive complex primary and revision total knee arthroplasties.

Background: To report incidence, microbiological findings, and treatment outcome of prosthetic joint infection (PJI) after constrained condylar knee arthroplasty.Methods: Retrospective study of 100 consecutive complex primary and revision total knee arthroplasties operated with constrained condylar knee arthroplasties between February 2006 and October 2015 at a single institution. Demographic and surgical data were registered, as well as data regarding infection, microbiology and treatment. Follow-up median 43 months; SD 32.Results: The overall incidence of acute postoperative PJI was low (3/100). 1/33 (3%), 1/ 45 (2%), and 1/22 (5%), following primary complex TKA, aseptic revisions, and septic revisions, respectively. The incidence of late acute hematogenous PJI was 5/100. 1/33 (3%),1/45 (2%), and 3/22 (14%) following primary complex TKA, aseptic revisions, and septic revisions, respectively. Late acute hematogenous infections were associated with a lower success rate of treatment with debridement and implant retention compared with acute postoperative PJIs, 1/5 versus 2/3.Conclusion: The risk of late acute hematogenous infections seems increased. Multiple previous surgery, poor soft tissue, and large metal implants may contribute to an increased lifelong susceptibility for bacteremias to cause PJIs.

Oral Therapy, Microbiological Findings, and Comorbidity Influence the Outcome of Prosthetic Joint Infections Undergoing 2-Stage Exchange

BackgroundThe aim of the present study was to investigate potential predictive factors of an unfavorable outcome in patients with prosthetic joint infection (PJI) undergoing 2-stage exchange. MethodsPatients with PJI undergoing 2-stage exchange and observed over a 5-year period (2009-2013) were included. Cure was defined by the disappearance of infection after a 96-week follow-up period. Statistical analysis was performed using the Mann-Whitney U test, the Fisher exact test, and the multivariate analysis. ResultsOne-hundred twenty-two patients with PJI were included (median age, 69 years [range, 36-80 years]; 48% males, 47 hip PJI, and 75 knee PJI). Known comorbidities related to an increased risk of infection were reported in 43 patients (35%). Microbiological definition was obtained in 101 (83%) patients, and Staphylococcus aureus was isolated in 44 (36%) patients. Coagulase-negative staphylococci were isolated in 41 (34%) patients. A favorable outcome was obtained in 102 of 122 patients (84%). After univariate analysis, bacterial growth from operative specimens (P = .007), growth of Gram-positive bacteria (P < .001), use of oral therapy (P = .01), and absence of known comorbidities (P = .02) were associated with favorable outcome. Administration of rifampin (P = .99) and results of blood analysis were not predictive of outcome. After multivariate analysis was applied, infection sustained by Gram-positive bacteria, administration of oral antibiotics, and absence of known comorbidities frequently resulted in favorable outcome. ConclusionA favorable outcome in patients with PJI undergoing 2-stage procedure was associated with an infection sustained by Gram-positive bacteria, absence of known comorbidities, and administration of oral therapy. Therefore, failure rate can be reduced with appropriate treatment choices.

Prosthetic joint infection—a devastating complication of hemiarthroplasty for hip fracture

Background and purpose — Hemiarthroplasty is the most common treatment in elderly patients with displaced femoral neck fracture. Prosthetic joint infection (PJI) is a feared complication. The infection rate varies in the literature, and there are limited descriptive data available. We investigated the characteristics and outcome of PJI following hemiarthroplasty over a 15-year period.Patients and methods — Patients with PJI were identified among 519 patients treated with hemiarthroplasty for a femoral neck fracture at Oslo University Hospital between 1998 and 2012. We used prospectively registered data from previous studies, and recorded additional data from the patients’ charts when needed.Results — Of the 519 patients, we identified 37 patients (6%) with early PJI. 20 of these 37 patients became free of infection. Soft tissue debridement and retention of implant was performed in 35 patients, 15 of whom became free of infection with an intact arthroplasty. The 1-year mortality rate was 15/37. We found an association between 1-year mortality and treatment failure (p = 0.001). Staphylococcus aureus and polymicrobial infection were the most common microbiological findings, each accounting for 14 of the 37 infections. Enterococcus spp. was found in 9 infections, 8 of which were polymicrobial. There was an association between polymicrobial infection and treatment failure, and between polymicrobial infection and 1-year mortality.Interpretation — PJI following hemiarthroplasty due to femoral neck fracture is a devastating complication in the elderly. We found a high rate of polymicrobial PJIs frequently including Enterococcus spp, which is different from what is common in PJI after elective total hip arthroplasty.

Prosthetic joint infection following hip fracture and degenerative hip disorder: a cohort study of three thousand, eight hundred and seven consecutive hip arthroplasties with a minimum follow-up of five years.

Prosthetic joint infections (PJIs) occur on a regular basis and with an increasing incidence. Under reporting of complications to national registries and unreliable ICD-10 coding increases the risk of under estimating the true rate of PJIs after hip arthroplasty. Also, the microbiology and final outcome is less well described, especially for hip-fracture patients operated upon with primary and secondary fracture prostheses. Our aim was to analyse re-operation rate, outcome and microbiology of PJIs following hip arthroplasty in patients operated upon due to hip fractures and degenerative hip disorders. This was a single-centre cohort study of 3807 consecutive hip arthroplasties performed between 1996 and 2005. The primary study outcome was to compare the incidence of PJIs. The secondary outcome was to analyse the microbiology and outcome of PJIs. We identified 62 PJIs: seven surgical-site PJIs were found in patients operated upon for a degenerative hip disorder, 22 [hazard ratio (HR) 4.3] were found in patients operated upon for a primary fracture and prosthesis and 25 (HR 6.1) in patients operated upon with a secondary fracture and prosthesis. Outcome treatment was unfavourable for hip fracture patients with a high rate of Girdlestone operation performed (22 of 27). Staphylococcal infections dominated in the fracture group, whereas polybacterial infections were more common in patients with degenerative hip disorder. Patients with a displaced femoral neck fracture treated primary or secondary with arthroplasties have a greater risk of PJIs and display worse outcomes compared with patients with a total hip replacement due to degenerative hip disorders.

Characteristics of prosthetic joint infections due to Enterococcus sp. and predictors of failure: a multi-national study

The objective of this study was to review the characteristics and outcome of prosthetic joint infections (PJI) due to Enterococcus sp. collected in 18 hospitals from six European countries. Patients with a PJI due to Enterococcus sp. diagnosed between January 1999 and July 2012 were retrospectively reviewed. Relevant information about demographics, comorbidity, clinical characteristics, microbiological data, surgical treatment and outcome was registered. Univariable and multivariable analyses were performed. A total of 203 patients met the inclusion criteria. The mean (SD) was 70.4 (13.6) years. In 59 patients the infection was diagnosed within the first 30 days (29.1%) from arthroplasty, in 44 (21.7%) between 31 and 90 days, in 54 (26.6%) between 91 days and 2 years and in 43 (21%) after 2 years. Enterococcus faecalis was isolated in 176 cases (89%). In 107 (54%) patients the infection was polymicrobial. Any comorbidity (OR 2.53, 95% CI 1.18–5.40, p 0.01), and fever (OR 2.65, 95% CI 1.23–5.69, p 0.01) were independently associated with failure. The only factor associated with remission was infections diagnosed later than 2 years (OR 0.25, 95% CI 0.09–0.71, p 0.009). In conclusion, prosthetic joint infections due to Enterococcus sp. were diagnosed within the first 2 years from arthroplasty in >70% of the patients, almost 50% had at least one comorbidity and infections were frequently polymicrobial (54%). The global failure rate was 44% and patients with comorbidities, fever, and diagnosed within the first 2 years from arthroplasty had a poor prognosis.

Clinical Characteristics and Outcomes of Prosthetic Joint Infection Caused by Small Colony Variant Staphylococci

ABSTRACTSmall colony variants (SCVs) are naturally occurring subpopulations of bacteria. The clinical characteristics and treatment outcomes of patients with prosthetic joint infection (PJI) caused by staphylococcal SCVs are unknown. This study was a retrospective series of 113 patients with staphylococcal PJI, with prospective testing of archived sonicate fluid samples. SCVs were defined using two-investigator review. Treatment failure was defined as (i) subsequent revision surgery for any reason, (ii) PJI after the index surgery, (iii) prosthesis nonreimplantation due to ongoing infection, or (iv) amputation of the affected limb. There were 38 subjects (34%) with SCVs and 75 (66%) with only normal-phenotype (NP) bacteria. Subjects with SCVs were more likely to have been on chronic antimicrobials prior to surgery (P = 0.048), have had prior surgery for PJI (P = 0.03), have had a longer duration of symptoms (P = 0.0003), and have had a longer time since joint implantation (P = 0.007), compared to those with only NP bacteria. Over a median follow-up of 30.6 months, 9 subjects (24%) with SCVs and 23 (32%) with only NP bacteria experienced treatment failure (P = 0.51). Subjects infected with Staphylococcus aureus were more likely to fail than were those infected with Staphylococcus epidermidis (hazard ratio [HR], 4.03; 95% confidence interval [CI], 1.80 to 9.04). While frequently identified in subjects with PJI and associated with several potential predisposing factors, SCVs were not associated with excess treatment failure compared to NP infections in this study, where they were primarily managed with two-stage arthroplasty exchange.

Oral Antibiotic Therapy

Oral Antibiotic Therapy

Irrigation and Debridement

Irrigation and Debridement

692Prognostic Value of Inflammatory Markers during Treatment of Prosthetic Joint Infections

• Arthroplasty is a cost-effective treatment for arthritis, but is complicated by a 1% incidence of Prosthetic Joint Infections (PJI). • During treatment of osteomyelitis or PJI, the inflammatory markers : Erythrocyte Sedimentation Rate (ESR) and Creactive protein (CRP) are expected to decrease. • The role of ESR and CRP in predicting outcome of prosthetic joint infections (PJI), treated with a 2-stage exchange, has been inconclusive. • There was a trend towards higher mean CRP value among patients who failed treatment (mean CRP 11.35 vs 4.13 mg/dL, p-value 0.054). • There was no significant difference in mean ESR (p = 0.50), change in ESR (p = 0.19) or change in CRP (p = 0.30) between the 2 groups. • Even though the difference was not significant, last value ESR and CRP were twice as high in the failure group. • No other predictors of treatment failure were identified.

Clinical characteristics, microbiology, and outcomes of prosthetic joint infection in Taiwan

Prosthetic joint infection (PJI) after total knee or hip replacement is a devastating complication associated with substantial morbidity and economic cost. The incidence of prosthetic joint infection is increasing as the use of mechanical joint replacement increases. The treatment approach to prosthetic joint infection is based on different clinical situations such as a patient's comorbidities, epidemic microbiology data, and surgical procedures. The aim of our study was to understand clinical characteristics of prosthetic joint infection, the microbiology of the prosthetic joint infection, and the outcomes of different treatment strategies during 2006-2011. We retrospectively collected cases of prosthetic joint infection in the National Taiwan University Hospital between January 1, 2006 and December 31, 2011. The patients' characteristics, microbiology, outcomes, and factors associated with treatment success were recorded. One hundred and forty-four patients were identified as having PJI. Of these, 92 patients were entered into per-protocol analysis. Staphylococcus aureus was the most common causative organism (29.9%), followed by coagulase-negative Staphylococci (16.7%), and Enterococci (9.7%). The overall treatment success rate was 50%. Patients who received a two-stage revision had a better outcome, compared to patients who underwent other types of surgeries (70% vs. 32.7%, respectively; p < 0.001). In multivariate analysis, the two-stage revision was significantly associated with treatment success (odds ratio = 3.923, 95% confidence interval = 1.53-10.04). Our study demonstrates that Staphylococcus aureus was the most common causative organisms in PJI. Performing two-stage revisions was significantly associated with a better outcome.

Incidence, secular trends, and outcomes of prosthetic joint infection: a population-based study, olmsted county, Minnesota, 1969-2007.

The epidemiology of prosthetic joint infection (PJI) in a population-based cohort has not been studied in the United States. To provide an accurate assessment of the true incidence, secular trends, clinical manifestations, microbiology, and treatment outcomes of PJI in a population-based cohort. Historical cohort study. Olmsted County, Minnesota. Residents who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA) between January 1, 1969, and December 31, 2007. Incidence rates and trends in PJI were assessed using the Kaplan-Meier method and log-rank test, as were treatment outcomes among PJI case patients. A total of 7,375 THAs or TKAs were implanted in residents of Olmsted County during the study period. Seventy-five discrete joints in 70 individuals developed PJI, during a mean ± SD follow-up of [Formula: see text] years. The cumulative incidence of PJI was 0.5%, 0.8%, and 1.4% after 1, 5, and 10 years after arthroplasty, respectively. Overall, the rate of survival free of clinical failure after treatment of PJI was 76.8% (95% confidence interval [CI], 64.3-85.2) and 65.2% (95% CI, 33.1-76.2) at 3 and 5 years, respectively. The incidence and treatment outcomes did not significantly differ by decade of implantation, patient age at implantation, gender, or joint location. The incidence of PJI is relatively low in a population-based cohort and is a function of age of the prosthesis. Incidence trends and outcomes have not significantly changed over the past 40 years.

Prosthetic joint infection in solid organ transplant recipients: a retrospective case‐control study

The clinical features and outcome of prosthetic joint infection (PJI) among solid organ transplant (SOT) recipients have not been characterized. We performed a retrospective, matched case-control study to examine potential risk factors. We reviewed cases of PJI among transplant recipients who were evaluated at the Mayo Clinic between 1989 and 2009. Cases were matched to non-infected controls based on transplant type, prosthetic joint type, and order of organ transplantation/joint implantation. Among 367 patients with both a joint prosthesis and an SOT, there were 12 cases of infection in those receiving immunosuppression. These occurred in 8 renal recipients, 3 liver recipients, and 1 heart transplant recipient. Six subjects had hip and 6 had knee arthroplasty infections. The observed time to prosthesis failure ranged from 0.5 to 148 months after implantation. Gram-positive bacteria (staphylococci and streptococci) caused the infection in 8 subjects. Two cases were caused by nontuberculous mycobacteria, whereas the remaining 2 cases were culture-negative in the setting of antimicrobial use. We did not find a statistically significant association between obesity, diabetes mellitus, or antimicrobial prophylaxis (given in the setting of immunosuppression) and development of PJI. A marginal association was seen between surgical site infection and the risk of PJI; however, this did not reach statistical significance. In our series, infection was mainly caused by gram-positive bacterial pathogens, similar to the commonly encountered organisms in the immunocompetent host, although opportunistic pathogens were also isolated.

Total hip replacement infected with Mycobacterium tuberculosis complicated by Addison disease and psoas muscle abscess: a case report

IntroductionProsthetic joint infection due to Mycobacterium tuberculosis is occasionally encountered in clinical practice. To the best of our knowledge, this is the first report of a prosthetic joint infection due to Mycobacterium tuberculosis complicated by psoas abscesses and secondary Addison disease.Case presentationA 67-year-old immunocompetent Caucasian woman underwent total left hip arthroplasty because of osteoarthritis. After 18 months, she underwent arthroplasty revision for a possible prosthetic infection. Periprosthetic tissue specimens for bacteria were negative, and empirical antibiotic therapy was unsuccessful. She was then admitted to our department because of complications arising 22 months after arthroplasty. A physical examination revealed a sinus tract overlying her left hip and skin and mucosal pigmentation. Her levels of C-reactive protein, basal cortisol, adrenocorticotropic hormone, and sodium were out of normal range. Results of the tuberculin skin test and QuantiFERON-TB Gold test were positive. Computed tomography revealed a periprosthetic abscess and the inclusion of the left psoas muscle. Results of microbiological tests were negative, but polymerase chain reaction of a specimen taken from the hip fistula was positive for Mycobacterium tuberculosis. Our patient's condition was diagnosed as prosthetic joint infection and muscle psoas abscess due to Mycobacterium tuberculosis and secondary Addison disease. She underwent standard treatment with rifampicin, ethambutol, isoniazid, and pyrazinamide associated with hydrocortisone and fludrocortisone. At 15 months from the beginning of therapy, she was in good clinical condition and free of symptoms.ConclusionsProsthetic joint infection with Mycobacterium tuberculosis is uncommon. A differential diagnosis of tuberculosis should be considered when dealing with prosthetic joint infection, especially when repeated smears and histology examination from infected joints are negative. Clinical outcomes of prosthetic joint infection by Mycobacterium tuberculosis are unpredictable, especially given the limited literature in this field and the uncertainty of whether medical treatment alone can eradicate the infection without prosthesis removal. Furthermore, this case report raises interesting issues such as the necessity of a follow-up evaluation after treatment based on clinical conditions, the utility of a more standardized length of treatment for periprosthetic tuberculous infection, and the importance of a high diffusion capacity of anti-mycobacterial agents in order to eradicate the infection.

Functional assessment of Toll-like receptor 2 and its relevance in patients with Staphylococcus aureus infection of joint prosthesis

Staphylococcus aureus induces inflammation in experimental models through Toll-like receptor 2 (TLR2). The clinical relevance of this observation is debated. We evaluated the relationship between TLR2 R753Q single nucleotide polymorphism (SNP) and S aureus infection of joint prosthesis. Human embryonic kidney 293 (HEK293) cells transfected with wild-type and mutant R753Q TLR2 gene were assessed for response to S aureus peptidoglycan. Real-time polymerase chain reaction and gene sequencing of DNA were performed to assess TLR2 R753Q SNP in 76 patients with S aureus prosthetic joint infection (PJI) and 208 noninfected controls. HEK293 cells expressing wild-type TLR2 gene responded robustly to S aureus peptidoglycan, while cells with mutant R753Q TLR2 gene did not. The prevalence of R753Q SNP was high in S aureus PJI patients (heterozygous in 8%, and homozygous in 22%), although not significantly different from controls (12% and 27%, respectively). The TLR2 variant allele was not significantly associated with the risk or survival free of recurrent PJI S aureus. In conclusion, TLR2 R753Q SNP disabled the cellular response to S aureus peptidoglycan in vitro. However, TLR2 R753Q SNP was not significantly associated with the risk or outcome of PJI due to S aureus in human patients.

Periprosthetic Infection Due to Resistant Staphylococci: Serious Problems on the Horizon

Prosthetic joint infections (PJI) caused by methicillin-resistant staphylococci represent a major therapeutic challenge. We examined the effectiveness of surgical treatment in treating infection of total hip or knee arthroplasty caused by methicillin-resistant staphylococcal strains and the variables influencing treatment success. One hundred and twenty-seven patients were treated at our institution between 1999 and 2006. There were 58 men and 69 women, with an average age of 66 years. Patients were followed for a minimum of 2 years or until recurrence of infection. Débridement and retention of the prosthesis was performed in 35 patients and resection arthroplasty in 92. Débridement controlled the infection in only 37% of cases whereas two-stage exchange arthroplasty controlled the infection in 75% of hips and 60% of knees. Preexisting cardiac disease was associated with a higher likelihood of failure to control infection in all treatment groups. Antibiotic-resistant Staphylococci continue to compromise treatment outcome of prosthetic joint infections, especially in patients with medical comorbidities. New preventive and therapeutic strategies are needed. Level IV, therapeutic study.

Outcome of Prosthetic Joint Infections Treated with Debridement and Retention of Components

Outcome of Prosthetic Joint Infections Treated with Debridement and Retention of Components

Outcome of Prosthetic Joint Infections Treated with Debridement and Retention of Components

Debridement and retention of the prosthesis represents an attractive surgical modality for treatment of prosthetic joint infection, but risk factors for treatment failure require clarification. We conducted a retrospective cohort analysis of all patients with a prosthetic joint infection who were treated with debridement and retention of the prosthesis at the Mayo Clinic (Rochester, Minnesota) between 1995 and 1999. Debridement and retention of the prosthesis was the initial treatment modality for 99 episodes of prosthetic joint infection that occurred in 91 patients who presented to the Mayo Clinic during 1995-1999. A total of 32% and 23% of all episodes were due to Staphylococcus aureus and coagulase-negative staphylococci, respectively. The median duration of intravenous antimicrobial therapy was 28 days (range, 1-90 days). Oral antimicrobial suppression was used in 89% of the episodes, for a median duration of 541 days (range, 5-2673 days). Treatment failure occurred in 53 episodes during a median follow-up period of 700 days (range, 1-2779 days). The 2-year survival rate free of treatment failure was 60% (95% confidence interval [CI], 50%-71%). Variables associated with an increased risk of treatment failure in multivariable analysis included the presence of a sinus tract (hazard ratio, 2.84; 95% CI, 1.48-5.44; P = .002) and a duration of symptoms prior to debridement of > or = 8 days (hazard ratio, 1.77; 95% CI, 1.02-3.07; P = .04). Debridement and retention of the prosthesis is a common surgical modality at our institution to treat prosthetic joint infection. Risk factors independently associated with treatment failure include the presence of a sinus tract and duration of symptoms prior to debridement of > or = 8 days.