BACKGROUND: Ratios of established inflammatory markers, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), have been used for diagnostic purposes in the surgical field; however, the ESR:CRP ratio (ECR) has not been evaluated as a marker for predicting infection resolution in patients with periprosthetic joint infections (PJIs). This study aimed to evaluate the diagnostic accuracy of ECR in predicting postoperative reinfection in patients who underwent debridement, antibiotics, and implant retention (DAIR). METHODS: This is a retrospective review of 179 consecutive patients who underwent DAIR revision total joint arthroplasty for PJI. Patients were stratified by acuity of their infection: acute PJI, acute hematogenous PJI, and chronic PJI. The area under the receiver operating characteristic curve was calculated to evaluate ECR as diagnostic marker for predicting postoperative reinfection in patients who underwent DAIR. RESULTS: Statistically significant differences in ECR were found in patients who underwent DAIR revision total joint arthroplasty for chronic infection (1.23 vs 2.33; P = .04). There was no significant difference in ECR in patients who underwent DAIR for acute infection (P = .70) and acute hematogenous infection (P = .56). In patients who underwent DAIR for chronic PJI, ECR demonstrated a sensitivity and specificity of 75% and 84%, respectively, for the prediction of postoperative reinfection, which was significantly higher than that of ESR (sensitivity, 67%; specificity, 47%; P < .001) and CRP (sensitivity, 50%; specificity, 26%; P < .001). CONCLUSION: Elevated ECR was associated with an increased reinfection risk in patients who underwent DAIR for chronic PJI, suggesting that preoperative ECR may be a useful predictor to identify patients at increased risk of reinfection after DAIR for chronic PJIs.

Periprosthetic joint infection (PJI) is a potentially devastating complication after total elbow arthroplasty (TEA) that can lead to significant morbidity for the patient as well as increased health care–related costs. Despite the potential morbidity associated with TEA PJI, evidence is limited regarding an optimal treatment algorithm. Initial management typically consists of either irrigation and debridement or 2-stage revision. A stable implant, a functioning triceps, and an intact soft tissue envelope are necessary to perform irrigation and debridement. Irrigation and debridement is associated with a relatively high risk of infection recurrence especially in chronic infections. Two-stage revision offers a lower recurrence risk, although there is a 25% chance of not completing the second stage. Resection arthroplasty, arthrodesis, and amputation are salvage options, whereas medical treatment, in the form of antibiotics alone, is reserved for poor surgical candidates. Further multicenter prospective study and retrospective review of registry data focusing on different treatment algorithms, prevention strategies, and functional outcomes would be helpful to elucidate the ideal management of elbow PJI.

Background The success of debridement, antibiotics, and implant retention (DAIR) in early periprosthetic joint infection (PJI) largely depends on the presence of a mature biofilm. At what time point DAIR should be disrecommended is unknown. This multicenter study evaluated the outcome of DAIR in relation to the time after index arthroplasty. Methods We retrospectively evaluated PJIs occurring within 90 days after surgery and treated with DAIR. Patients with bacteremia, arthroscopic debridements, and a follow-up &lt;1 year were excluded. Treatment failure was defined as (1) any further surgical procedure related to infection; (2) PJI-related death; or (3) use of long-term suppressive antibiotics. Results We included 769 patients. Treatment failure occurred in 294 patients (38%) and was similar between time intervals from index arthroplasty to DAIR: the failure rate for Week 1–2 was 42% (95/226), the rate for Week 3–4 was 38% (143/378), the rate for Week 5–6 was 29% (29/100), and the rate for Week 7–12 was 42% (27/65). An exchange of modular components was performed to a lesser extent in the early post-surgical course compared with the late course (41% vs 63%, respectively; P &lt; .001). The causative microorganisms, comorbidities, and durations of symptoms were comparable between time intervals. Conclusions DAIR is a viable option in patients with early PJI presenting more than 4 weeks after index surgery, as long as DAIR is performed within at least 1 week after the onset of symptoms and modular components can be exchanged.

Abstract. Background: Fungal prosthetic joint infections (PJIs) are rare and often associated with poor outcome; however, risk factors are not well described.Methods: This was a retrospective case control study among all patients with PJIs from 2006-2016 at two major academic centers. Each fungal PJI case was matched 1:1 with a bacterial PJI control by joint (hip, knee, shoulder) and year of diagnosis. We compared demographics, comorbidities, and clinical characteristics between cases and controls using chi square/Fisher's exact or Wilcoxon rank sum test. Independent risk factors were identified with multivariable logistic regression.Results: Forty-one fungal PJIs occurred over the study and 61% were due to Candida albicans. The hip was involved in 51.2% of cases, followed by the knee (46.3%). Compared to bacterial PJI, fungal PJI cases were more likely to have received antibiotics within the previous 3 months (70.7% vs 34%, P=.001), wound drainage lasting >5 days (48% vs 9%, P=.0002), had a lower median CRP (2.95 mg/dl vs 5.99, P=.013) and synovial fluid white blood cell count (13,953 cells/mm3 vs 33,198, P=.007), and a higher proportion of prior two-stage exchanges (82.9% vs 53.6%, P=.008). After controlling for center, prolonged wound drainage (OR, 7.3; 95% CI, 2.02-26.95) and recent antibiotics (OR, 3.4; 95% CI, 1.2-9.3) were significantly associated with fungal PJI.Conclusion: In our study, Candida albicans was the most common species in fungal PJIs and prolonged wound drainage and recent antibiotics were independent risk factors. These clinical characteristics may help providers anticipate fungal PJI and adjust management strategies.

Background Serum C-reactive protein (CRP) is an important test in the initial diagnosis of prosthetic joint infection (PJI). There is no widely accepted algorithm for the resolution of PJI. Surgeons have traditionally used CRP to determine if the infection has resolved. However, this practice is not currently supported by significant data.  Methods A retrospective analysis of our departmental arthroplasty database was conducted to determine mean values of CRP pre and postoperatively for PJI treated with the debridement, antibiotics and implant retention (DAIR) procedure, single-stage revision and two-stage revision. Receiver operating characteristic (ROC) curves were calculated to determine the sensitivity and specificity of CRP testing in diagnosing persistent infection. Results Of the 121 patients who had undergone treatment (75 hip replacements and 48 knee replacements), there were 26 cases of persistent infection. There was no statistical significance in the mean CRP values between successful and unsuccessful treatment groups. The areas under ROCs (AUCs) for CRP values predicting outcomes ranged from 0.46 to 0.73. Conclusion Our study does not support the use of serial CRP monitoring as an indicator of the successful eradication of PJI.

BACKGROUND: Total knee arthroplasty (TKA) periprosthetic joint infection (PJI) can be managed with debridement, antibiotic therapy, and implant retention (DAIR). Oral antibiotics can be used after DAIR for an extended time period to improve outcomes. The objective of this study was to compare DAIR failure rates and adverse events between an initial course of intravenous antibiotic therapy and the addition of extended treatment with oral antibiotics. METHODS: A multicenter observational study of patients diagnosed with a TKA PJI who underwent DAIR was performed. The primary outcome of interest was the failure rate derived from the survival time between the DAIR procedure and future treatment failure. RESULTS: One hundred eight patients met inclusion criteria; 47% (n = 51) received an extended course of oral antibiotics. These patients had a statistically significant lower failure rate compared to those who received only intravenous antibiotics (hazard ratio, 2.47; P = .009). Multivariable analysis demonstrated that extended antibiotics independently predicted treatment success, controlling for other variables. There was no significant difference in failure rates between an extended course of oral antibiotics less or more than 12 months (P = .23). No significant difference in the rates of adverse events was observed between patients who received an initial course of antibiotics alone and those who received a combination of initial and extended antibiotic therapy (P = .59). CONCLUSIONS: Extending therapy with oral antibiotics had superior infection-free survival for TKA PJI managed with DAIR. There was no increase in adverse events, demonstrating safety. After 1 year, there appears to be no significant benefit associated with continued antibiotic therapy.

Background We sought to determine the ultimate fate of patients undergoing resection arthroplasty as a first stage in the process of 2-stage exchange and evaluate risk factors for modes of failure. Methods A retrospective case study was performed including all patients with minimum 2-year follow-up who underwent first-stage resection of a hip or knee periprosthetic joint infection from 2008 to 2015. Patient demographics, laboratory, and health status variables were collected. The primary outcome analyzed was defined as failure to achieve an infection-free 2-stage revision. Univariate pairwise comparison followed by multivariate regression analysis was used to determine risk factors for failure outcomes. Results Eighty-nine patients underwent resection arthroplasty in a planned 2-stage exchange protocol (27 hips, 62 knees). Mean age was 64 years (range, 43-84), 56.2% were males, and mean follow-up was 56.3 months. Also, 68.5% (61/89) of patients underwent second-stage revision. Of the 61 patients who complete a 2-stage protocol, 14.8% (9/61) of patients failed with diagnosis of repeat or recurrent infection. Mortality rate was 23.6%. Multivariate analysis identified risk factors for failure to achieve an infection-free 2-stage revision as polymicrobial infection (P < .004; adjusted odds ratio [AOR], 7.8; 95% confidence interval [CI], 2.1-29.0), McPherson extremity grade 3 (P < .024; AOR, 4.1; 95% CI, 1.2-14.3), and history of prior resection (P < .013; AOR, 4.7; 95% CI, 1.4-16.4). Conclusion Patients undergoing resection arthroplasty for periprosthetic joint infection are at high risk of death (24%) and failure to complete the 2-stage protocol (32%). Those who complete the 2-stage protocol have a 15% rate of reinfection at 4.5-year follow-up.

Biofilm-active antibiotics are suggested to improve the outcome in periprosthetic joint infection (PJI). However, the type, dose and duration of antibiotic treatment is rarely specified and their impact on outcomes is unknown. In this prospective cohort study, the infection and functional outcome were compared in 131 patients with knee PJI treated with or without biofilm-active antibiotics. The infection and functional outcome were evaluated by the Kaplan–Meier survival method to estimate the probability of infection-free survival; comparison between subgroups was performed by log-rank test. The influence of variables on the survival probability was analysed using univariate and multivariate Cox proportional-hazards regression models. Functional outcome was evaluated by pain intensity and the Knee injury and Osteoarthritis Outcome Score (KOOS). Among the 131 patients, 55 (42%) were treated with biofilm-active antibiotics and 76 (58%) were treated with non-biofilm-active antibiotics. The median follow-up period was 3.7 years (range, 2.0–7.6 years), and the infection-free survival probability was 74% (95% CI 61–85%) after 1 year and 56% (95% CI 47–66%) after 2 years. Infection-free survival after 1 year was better for patients who received biofilm-active antibiotics compared with those who did not (83% vs. 70%; P = 0.040) and remained superior after 2 years (67% vs. 48%; P = 0.038). In addition, biofilm-active antibiotic treatment was associated with lower pain intensity (P = 0.006) and higher KOOS on all five subscales. In patients with knee PJI, biofilm-active antibiotic therapy was associated with better infection outcome, lower pain intensity and better joint function.

Background: A number of clinical trials have been conducted, assessing the role of long-term (>1 year) suppressive antibiotic treatment (SAT) combined with Debridement, Antibiotics, and Implant Retention (DAIR) for the management of peri-prosthetic joint infection (PJI). However, no systematic review of the literature has been published to date to evaluate complications associated with long-term antibiotic treatment and overall survivorship free from re-operation and revision for infection after DAIR for total hip and total knee PJI. Methods: The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried for publications from January 1980 to December 2018 utilizing keywords pertinent to total knee arthroplasty, total hip arthroplasty, PJI, and antibiotic suppression. Results: Overall, 7 articles of low quality (level III or IV) were included in this analysis. The studies included in this systematic review included 437 cases of PJI treated surgically with DAIR and then with SAT. The overall mean infection-free rate of SAT following DAIR was 75% (318/424 patients), while the all-cause re-operation rate was 6.7%. Overall, the mean rate of adverse effects associated with long-term antibiotic use was 15.4% and the mean rate of adverse effects leading to discontinuation of SAT was 4.3%. There was no study to show significant differences between acute (either post-operative or hematogenous, with onset of symptoms ≤4 weeks) and chronic (onset of symptoms >4 weeks) infections and failure rates of DAIR with SAT. The literature is inconclusive on the influence of anatomic location (hip vs knee) as well as microorganism on the success rate of DAIR with SAT. Conclusion: The results of this systematic review demonstrate that there is still only low-quality evidence regarding the therapeutic effect of DAIR combined with SAT, which is not enough to draw definitive conclusions. Furthermore, high-quality prospective studies are needed to better understand SAT's efficacy and safety in a controlled fashion. Although discontinuation of antibiotic treatment due to side effects was found to be low, the high rates of adverse effects noted after DAIR with SAT demonstrate the underlying frailty and complexity of many patients with PJI, and the imperfect therapies available. Although Staphylococcus aureus appears to be a risk factor for increased risk of SAT failure, there are not enough data to establish which patients would benefit most from DAIR with post-operative SAT.

Aims The aim of this study was to determine if a three-month course of microorganism-directed oral antibiotics reduces the rate of failure due to further infection following two-stage revision for chronic prosthetic joint infection (PJI) of the hip and knee. Methods A total of 185 patients undergoing a two-stage revision in seven different centres were prospectively enrolled. Of these patients, 93 were randomized to receive microorganism-directed oral antibiotics for three months following reimplantation; 88 were randomized to receive no antibiotics, and four were withdrawn before randomization. Of the 181 randomized patients, 28 were lost to follow-up, six died before two years follow-up, and five with culture negative infections were excluded. The remaining 142 patients were followed for a mean of 3.3 years (2.0 to 7.6) with failure due to a further infection as the primary endpoint. Patients who were treated with antibiotics were also assessed for their adherence to the medication regime and for side effects to antibiotics. Results Nine of 72 patients (12.5%) who received antibiotics failed due to further infection compared with 20 of 70 patients (28.6%) who did not receive antibiotics (p = 0.012). Five patients (6.9%) in the treatment group experienced adverse effects related to the administered antibiotics severe enough to warrant discontinuation. Conclusion This multicentre randomized controlled trial showed that a three-month course of microorganism-directed, oral antibiotics significantly reduced the rate of failure due to further infection following a two-stage revision of total hip or knee arthroplasty for chronic PJI. Cite this article: Bone Joint J 2020;102-B(6 Supple A):3–9.