Risk Factors for Recurrence of Periprosthetic Knee Infection

Unveiling the link: highly porous tantalum-augmented implants and periprosthetic joint infection in revision total knee arthroplasty-a systematic review and meta-analysis

BACKGROUND

The trend of the literature suggests that tantalum (Ta) may possess antibacterial properties. However, no consensus has been reached on Ta's preventive role in periprosthetic joint infection (PJI) in patients undergoing revision total knee arthroplasty (rTKA).

QUESTION

What is the PJI incidence rate after rTKA using Ta-augmented implants for both septic and all-cause revision reasons? Is there a difference in the PJI rate following rTKA performed using Ta-augmented implants compared to non-Ta implants?

METHODS

Using 5 major databases, the authors searched for studies reporting the rate of PJIs following rTKA using Ta-augmented implants until January 2022. The PJI rates for the Ta group were pooled, compared to the control group, and presented as odds ratios (OR) and 95% confidence intervals (CI) using forest plots.

RESULTS

Thirty eligible studies involving 881 knees were included. The overall PJI rate following rTKA using Ta-augmented implants was 8.1% (CI = 6.6%-9.9%). Specifically, in cases of septic revision, the infection rate was 15.7% (95% CI = 11.7%-20.7%). The comparative analysis indicated a similar PJI rate between the Ta- augmented and non-Ta group across 3 studies, which was found to be similar (OR = 0.52, 95% CI = 0.13-2.0, P = 0.35).

CONCLUSION

PJI poses a significant risk following both aseptic and septic revision rTKA, even when Ta-augmented implants were administrated. The rate of PJI after rTKA was similar for Ta- augmented implants and non-Ta implants. Further rigorous studies with a high level of evidence are essential to definitively determine the potential impact of Ta derivatives on infection rates following rTKA, particularly in septic revision.

LEVEL OF EVIDENCE

IV.

Infection control rate in two-stage exchange for chronic periprosthetic joint infection: a retrospective cohort study focusing on antibiotic-free period

BACKGROUND

Limited information is available regarding the impact of antibiotic holidays on the infection control rate of two-stage revisions for chronic periprosthetic joint infection (PJI). This study aims to evaluate the impact of an antibiotic holiday on the infection control rate after two-stage exchange for PJI.

METHODS

We retrospectively analyzed data from patients with chronic PJI who underwent long-interval two-stage exchange using joint spacers at our center from June 2012 to June 2021. Patients were divided into Short Antibiotic Holiday (SAH, antibiotic holiday < 3 months) and Long Antibiotic Holiday (LAH, antibiotic holiday ≥ 3 months) groups. Following completion of the two-stage exchange treatment, patients were monitored for a minimum of 2 years to determine the infection control rate.

RESULTS

A total of 75 chronic PJI patients were included, comprising 42 hip and 33 knee cases. In chronic PJI of the hip, the LAH group demonstrated a significantly higher infection control rate compared to the SAH group (27/27 vs 12/15, p = 0.016). For chronic PJI of the knee, the infection control rate in the LAH group was comparable to that in the SAH group (20/21 vs 10/12, p = 0.238). Furthermore, no significant differences in clinical outcomes were observed between the LAH and SAH groups.

CONCLUSIONS

A ≥ 3-month antibiotic holiday, without compromising postoperative functional recovery, may enhance infection control rates after two-stage exchange for chronic hip PJI using joint spacers.

Risk factors of recurrent periprosthetic joint infection of the knee after two-stage reimplantation

INTRODUCTION

Prosthetic joint infection (PJI) is one of the most common and detrimental complications of total knee replacement arthroplasty (TKA). Despite extensive efforts, including two-stage reimplantation, to eradicate PJI, it still recurs in a substantial number of patients. However, the risk factors of recurrence after two-stage reimplantation of the knee have not been established. In this study, it is hypothesized that there will be certain risk factors of recurrence after two-stage reimplantation for PJI of the knee.

MATERIALS AND METHODS

From March 2002 to December 2022, 65 knees that underwent two-stage reimplantation for PJIs in a single, tertiary hospital were retrospectively reviewed, and 44 patient-related, laboratory-related, and surgery-related factors, including body mass index, pathogen type, and the usage of transfusions, were selected as the potential risk factors for recurrence. Survival analysis using the Kaplan-Meier method and subsequent Cox proportional hazard regression were performed.

RESULTS

Out of the 65 knees that underwent two-stage reimplantation, infection recurred in 15 knees (23.1%) in a median 11 (range 4-108) months. The Cox proportional hazards regression showed that infection of revision TKA, mixed pathogen-type infection, and higher serum erythrocyte sedimentation rate (ESR, mm/h) level increases the risk of recurrence (p-values < 0.001, 0.04, and 0.009; hazard ratios 40.29, 1.53, and 1.03, respectively).

CONCLUSIONS

A significant portion of PJI of the knees recurred after two-stage reimplantation. Revision TKA at the time of initial PJI, mixed pathogen-type infection, and higher serum ESR level were three significant risk factors of PJI recurrence. Surgeons should be more cautious in suspecting PJI relapse for these specific occasions.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Identifying potential predictive indicators for reimplantation timing in two-stage revision: a meta-analysis and system review

PURPOSE

The two-stage exchange revision represents a pivotal strategy in the management of prosthetic joint infections, wherein the judicious timing of reimplantation serves as a crucial determinant for therapeutic success. At present, attempts have been made to utilize predictive models to establish the optimal timing for reimplantation; however, their predictive accuracy remains unsatisfactory. This inadequacy primarily arises from the lack of dependable predictive indicators, which demonstrate inconsistent effectiveness across various studies and occasionally yield contradictory outcomes. Therefore, identifying solid predictive indicators is in desperate need.

METHODS

Studies reporting outcomes of the two-stage exchange revision till June, 2023 were systematically retrieved, screened and subject to quality analysis. Basic characteristics of these studies were firstly summarized. Subsequently, factors of interest regarding clinical information, blood and body fluid test results, pathogen test results of the recurrent and recurrent-free cohorts were extracted and submitted to a fixed or random effects model. Meanwhile, evaluation of publication bias and sensitivity was performed.

RESULTS

After filtering, a total of 45 studies were finally involved. Pooled analysis suggested that the recurrent cohort exhibited elevated incidences of body mass index (BMI) > 30, smoking and alcohol habits, diabetes, sinus tract, positive culture, and G-, polymicrobial and drug-resistant infections. Additionally, higher levels of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), synovial white blood cell (WBC) count, and polymorphonuclear percentage (PMN%) were observed in the recurrent cohort. On the other hand, the results of D-dimer and fibrinogen were ambiguous, and no difference regarding peripheral WBC count was observed. Forest plots suggested a low risk of publication bias. Besides, sensitivity analysis indicated good stability of the aforementioned indicators, except D-dimer and fibrinogen.

CONCLUSION

To sum up, BMI > 30, smoking and alcohol habits, diabetes, sinus tract, positive culture, and G-, polymicrobial and drug-resistant infections, CRP, ESR, synovial WBC and PMN% exhibited significant differences between recurrent and recurrent-free cohorts. Therefore, these indicators may be considered as potential predictive factors for the further development of a prognostic model that aids the determination of reimplantation timing. Nevertheless, the efficacy of these indicators remains to be further confirmed.

REGISTRATION NUMBER

Prospero ID: CRD42022296568.

Advancements in treatment strategies for periprosthetic joint infections: A comprehensive review

Periprosthetic joint infection (PJI) presents a critical challenge in orthopedic care, contributing to significant patient morbidity and healthcare costs. This burden is expected to increase secondary to growing demand for total joint arthroplasty (TJA). Despite the profound significance of PJI, there is currently no universally accepted "gold standard" diagnostic criteria using serum biomarker thresholds; latest criteria fail to differentiate acute infections from chronic or consider time since initial surgery. Furthermore, contemporary PJI treatment, which conventionally requires 2-stage revision surgery in conjunction with rigorous antibiotic treatment, can be particularly taxing on patients. Fortunately, recent years have seen marked evolution in both PJI diagnosis and treatment methods. Contemporary research supports time-dependent serum biomarker thresholds with greater sensitivity and specificity than previously reported, as well as alternative surgical options which may be more suitable for certain patients. The following narrative review aims to describe the significance and pathogenesis of PJI before characterizing current challenges, novel innovations, and the future landscape of PJI diagnosis and management. Here, we spotlight the emerging utility of novel biomarkers and metagenomic next-generation sequencing for diagnosis, advancements in patient-centered surgical outcome prediction tools for PJI risk assessment and prevention, and evolving surgical techniques including 1-stage and a "hybrid" 1.5-stage revision surgeries. Additionally, we explore cutting-edge therapeutic modalities including peptide and bacteriophage-based treatments, intraoperative anti-biofilm gel, the VT-X7 antibiotic pump, and promising immune-based interventions. Ultimately, these advancements hold the potential to revolutionize PJI management, offering hope for improved outcomes and reduced burdens on healthcare systems.

Intramedullary Positive Tissue Culture Increases the Risk of Reinfection Following One-Stage Septic Revision Total Knee Arthroplasty

BACKGROUND

Intraoperative acquisition of representative tissue samples is essential during revision arthroplasty of the infected total knee arthroplasty (TKA). While the number of intraoperative tissue samples needed to identify the organism is well described in the literature, there is still a paucity of evidence regarding the location of positive intraoperative samples and their correlation to postoperative outcomes.

METHODS

There were forty-two patients who had septic failure following one-stage revision TKA for periprosthetic joint infection who were identified between January 2009 and December 2017. They were matched to a control group of patients who had successful one-stage revision TKA without septic failure. The location of positive intraoperative tissue samples was categorized as: 1) soft tissue; 2) interface between bone and prosthesis; and 3) intramedullary (IM). Chi-square, Student's t-, and Wilcoxon Mann-Whitney U-tests were used as appropriate. Univariate and multivariate logistic regression analyses were performed to evaluate predictors of septic failure.

RESULTS

Weight > 100 kilograms (P = .033), higher Charlson Comorbidity Index (P < .001), and positive IM cultures (P < .001) were associated with a higher risk of reinfection after one-stage revision TKA. A positive IM sample carried a nearly five-fold increase in odds of reinfection (odds ratio 4.86, 95% confidence interval 1.85 to 12.78, P = .001).

CONCLUSIONS

A positive IM culture sample is significantly associated with septic failure after one-stage exchange for periprosthetic joint infection of the knee. Patients who had positive IM cultures may benefit from longer postoperative antibiotic therapy for the treatment of one-stage exchange arthroplasty to minimize the risk of reinfection.

Socioeconomic Disadvantage Predicts Decreased Likelihood of Maintaining a Functional Knee Arthroplasty Following Treatment for Prosthetic Joint Infection

BACKGROUND

Prosthetic joint infection (PJI) carries major morbidity and mortality as well as a complicated and lengthy treatment course. In patients who have high degrees of socioeconomic disadvantage, this may be a particularly devastating complication. Our study sought to evaluate the impact of socioeconomic deprivation on outcomes following treatment for PJI of the knee.

METHODS

We conducted a retrospective review of revision total knee arthroplasty (TKA) procedures performed for the treatment of initial PJI between 2008 and 2020 at a single tertiary care center in the United States. The Area Deprivation Index (ADI) was used to quantify socioeconomic deprivation. The primary outcome measure was presence of a functional knee joint at the time of most recent follow-up defined as TKA components or an articulating spacer. A total of 96 patients were included for analysis. The median follow-up duration was 26.5 months.

RESULTS

There was no significant difference in the rate of treatment failure (P = .63). However, the proportion of patients who had a functional knee arthroplasty (in contrast to having undergone arthrodesis, amputation, or retention of a static spacer) declined significantly with increasing ADI index (81.8% for the least disadvantaged group, 58.7% for the middle group, 42.9% for the most disadvantaged group, P = .021).

CONCLUSIONS

Patients who have a higher socioeconomic disadvantage as measured by ADI are less likely to maintain a functional knee arthroplasty following treatment for TKA PJI. These findings support continued efforts to improve access to care and optimize treatment plans for patients who have socioeconomic disadvantage.

Ideal Timing of Reimplantation in Patients with Periprosthetic Knee Infection Undergoing 2-Stage Exchange: A Diagnostic Scoring System

BACKGROUND

This study evaluated appropriate thresholds for serum biomarkers, synovial fluid white blood cell (SF-WBC) count, and synovial fluid neutrophil (polymorphonuclear leukocyte [PMN]) percentage to predict infection in a patient group who underwent definitive reimplantation after receiving a continuous course of antibiotic therapy for chronic knee periprosthetic joint infection (PJI). These thresholds were then used to generate a scoring system to predict recurrence (or persistence) of infection.

METHODS

The study included 153 patients with a median age of 73 years (range, 46 to 91 years) who underwent 2-stage revision for chronic knee PJI. Staphylococci were identified at baseline in 107 (70%) of the patients. After the 96-week follow-up period, 12% (19) of the 153 patients had recurrence of the PJI. A receiver operating characteristic (ROC) curve analysis was used to assess the predictive value of common serum biomarkers and SF aspiration before reimplantation, and the area under the curve (AUC) was evaluated. Variables that were significantly different between patients with and without infection recurrence were evaluated using a multivariable logistic regression model. A half-integer-point scoring system was created based on the final beta coefficients.

RESULTS

Regarding the prediction of recurrent infection, a D-dimer level of >1110 ng/mL yielded a sensitivity of 74%, specificity of 61%, and AUC of 0.69; an SF-WBC count of >934 cells/µL showed a sensitivity of 68%, specificity of 90%, and AUC of 0.79; and an SF-PMN percentage of >52% showed a sensitivity of 73%, specificity of 90%, and AUC of 0.82. The beta coefficients were approximated to 1.5 for the D-dimer level and to 2 for the SF-WBC count and SF-PMN percentage. A total score of >2 was used to classify patients with a high risk of infection recurrence. The ability to discriminate infection recurrence was demonstrated by an AUC of 0.90 (95% confidence interval: 0.82 to 0.99).

CONCLUSIONS

Patients with a score of >2 on our proposed scoring system based on serum biomarkers, SF-WBC count, and SF-PMN percentage should not undergo reimplantation, as they are at a high risk for recurrent PJI. Patients with a score of ≤2 can undergo definitive reimplantation with the lowest risk of recurrence.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

A mapping review on preoperative prognostic factors and outcome measures of revision total knee arthroplasty

To map literature on prognostic factors related to outcomes of revision total knee arthroplasty (rTKA), to identify extensively studied factors and to guide future research into what domains need further exploration. We performed a systematic literature search in MEDLINE, Embase, and Web of Science. The search string included multiple synonyms of the following keywords: "revision TKA", "outcome" and "prognostic factor". We searched for studies assessing the association between at least one prognostic factor and at least one outcome measure after rTKA surgery. Data on sample size, study design, prognostic factors, outcomes, and the direction of the association was extracted and included in an evidence map. After screening of 5,660 articles, we included 166 studies reporting prognostic factors for outcomes after rTKA, with a median sample size of 319 patients (30 to 303,867). Overall, 50% of the studies reported prospectively collected data, and 61% of the studies were performed in a single centre. In some studies, multiple associations were reported; 180 different prognostic factors were reported in these studies. The three most frequently studied prognostic factors were reason for revision (213 times), sex (125 times), and BMI (117 times). Studies focusing on functional scores and patient-reported outcome measures as prognostic factor for the outcome after surgery were limited (n = 42). The studies reported 154 different outcomes. The most commonly reported outcomes after rTKA were: re-revision (155 times), readmission (88 times), and reinfection (85 times). Only five studies included costs as outcome. Outcomes and prognostic factors that are routinely registered as part of clinical practice (e.g. BMI, sex, complications) or in (inter)national registries are studied frequently. Studies on prognostic factors, such as functional and sociodemographic status, and outcomes as healthcare costs, cognitive and mental function, and psychosocial impact are scarce, while they have been shown to be important for patients with osteoarthritis.

Reinfection rates after one- and two-stage revision surgery for hip and knee arthroplasty: a systematic review and meta-analysis

PURPOSE

Revisions for periprosthetic joint infection of knee and hip arthroplasty can be performed following one- or two-stage treatment protocols. Current literature is inconclusive whether one protocol is superior to the other, as prior literature reported similar reinfection rates for both treatment options. We aimed to provide a systematic review and meta-analysis of current literature on septic arthroplasty revisions.

METHODS

Between April 2015 and December 2020, Medline, Embase, and The Cochrane Library were searched for studies reporting reinfection outcomes in patients treated with one-stage and two-stage knee or hip revision arthroplasty. Two reviewers independently extracted data and disagreements were resolved by a third investigator. We utilized a double arcsine transformation, prior to pooling using a random-effects model.

RESULTS

For hip revision arthroplasty, we identified 14 one-stage studies (n = 1237) with a pooled reinfection rate of 5.7% (95% CI 3.7-8.1%), and 46 two-stage studies (n = 5009) with a reinfection rate of 8.4% (95% CI 6.9-9.9%). For knee revision arthroplasty, 6 one-stage studies (n = 527) and 48 two-stage studies (n = 4344) were identified with reinfection rates of 12.7% (7.0-19.7%) and 16.2% (13.7-19.0%), respectively. Overall, reinfection rates did not vary substantially after subgroup analysis. Limitations of our study are the limited amount of one-stage studies that introduce a potential bias.

CONCLUSION

The reinfection rates following one- and two-stage hip and knee arthroplasty revisions were similar. Knee reinfection rates have increased compared to the previous analysis. Individual patient characteristics and adequate treatment algorithms are needed for a more individual selection approach, until a randomized trial is performed.

The Cost-Effectiveness of Closed Incisional Negative Pressure Wound Therapy for Infection Prevention after Revision Total Knee Arthroplasty

Recent investigations have shown that closed incisional negative pressure wound therapy (ciNPWT) decreases the rate of postoperative wound complications following revision total knee arthroplasty (TKA). In this study, we used a break-even analysis to determine whether ciNPWT is a cost-effective measure for reducing prosthetic joint infection (PJI) after revision TKA. The cost of ciNPWT, cost of treatment for PJI, and baseline infection rates following revision TKA were collected from institutional data and the literature. The absolute risk reduction (ARR) in infection rate necessary for cost-effectiveness was calculated using break-even analysis. Using our institutional cost of ciNPWT ($600), this intervention would be cost-effective if the initial infection rate of revision TKA (9.0%) has an ARR of 0.92%. The ARR needed for cost-effectiveness remained constant across a wide range of initial infection rates and declined as treatment costs increased. The use of ciNPWT for infection prevention following revision TKA is cost-effective at both high and low initial infection rates, across a broad range of treatment costs, and at inflated product expenses.

The Cost-Effectiveness of Extended Oral Antibiotic Prophylaxis for Infection Prevention After Total Joint Arthroplasty in High-Risk Patients

BACKGROUND

Extended oral antibiotic prophylaxis may decrease rates of prosthetic joint infection (PJI) after total joint arthroplasty (TJA) in patients at high risk for infection. However, the cost-effectiveness of this practice is not clear. In this study, we used a break-even economic model to determine the cost-effectiveness of routine extended oral antibiotic prophylaxis for PJI prevention in high-risk TJA patients.

METHODS

Baseline PJI rates in high-risk patients, the cost of revision arthroplasty for PJI, and the costs of extended oral antibiotic prophylaxis regimens were obtained from the literature and institutional purchasing records. These variables were incorporated in a break-even economic model to calculate the absolute risk reduction (ARR) in infection rate necessary for extended oral antibiotic prophylaxis to be cost-effective. ARR was used to determine the number needed to treat (NNT).

RESULTS

Extended oral antibiotic prophylaxis with Cefadroxil in patients at high risk for PJI was cost-effective at an ARR in baseline infection rate of 0.187% (NNT = 535) and 0.151% (NNT = 662) for TKA and THA, respectively. Cost-effectiveness was preserved with varying costs of antibiotic regimens, PJI treatment costs, and infection rates.

CONCLUSION

The use of extended oral antibiotic prophylaxis may reduce PJI rates in patients at high risk for infection following TJA and appears to be cost-effective. However, the current evidence supporting this practice is limited in quality. The use of extended oral antibiotic prophylaxis should be weighed against the possible development of future antimicrobial resistance, which may change the value proposition.

Synovial Cell Count Before Reimplantation Can Predict the Outcome of Patients with Periprosthetic Knee Infections Undergoing Two-stage Exchange

BACKGROUND

Although synovial fluid can be used to diagnose periprosthetic joint infections (PJI) effectively, only the cutoff values adopted at the time of PJI diagnosis have been standardized, and few data are currently available about effectiveness of synovial fluid examination before definitive reimplantation.

QUESTIONS/PURPOSES

We asked: (1) What are the most appropriate thresholds for synovial fluid leukocyte counts (WBC) and neutrophil percentage (PMN percentage) in a patient group undergoing definitive reimplantation after an uninterrupted course of antibiotic therapy for chronic PJI? (2) What is the predictive value of our synovial WBC and PMN percentage threshold compared with previously proposed thresholds?

METHODS

In all, 101 patients with PJI were evaluated for inclusion from January 2016 to December 2018. Nineteen percent (19 of 101) of patients were excluded because of the presence of a chronic inflammatory disease, acute/late hematogenous infection, low amount of synovial fluid for laboratory investigations or infection persistence after spacer placement, and adequate antibiotic therapy. Finally, 81% (82 of 101) of patients with a median (range) age of 74 years (48 to 92) undergoing two-stage revision for chronic TKA infection, who were followed up at our institution for a period 96 weeks or more, were included in this study. The patients did not discontinue antibiotic treatment before reimplantation and were treated for 15 days after reimplantation if intraoperative cultures were negative. No patient remained on suppressive treatment after reimplantation. Synovial fluid was aspirated aseptically with a knee spacer in place to evaluate the cell counts before reimplantation. Thirteen percent (11 of 82) of patients had persistent or recurrent infection, defined as continually elevated erythrocyte sedimentation rate or C-reactive protein levels coupled with local signs and symptoms or positive cultures. The synovial fluid WBC counts and PMN percentage from the 11 patients with persistent or recurrent PJI were compared with the 71 patients who were believed to be free of PJI. Receiver operating characteristic (ROC) curve analyses assessed the predictive value of the parameters, and the areas under the curves (AUCs) were evaluated. The sensitivities, specificities, and positive and negative predictive values were determined for the WBC count and PMN percentage. Patients with persistent or recurrent infection had higher median WBC counts (471 cells/µL versus 1344 cells/µL; p < 0.001) and PMN percentage (36% versus 61%; p < 0.001) than did patients believed to be free of PJI.

RESULTS

ROC curve analysis identified the best threshold values to be a WBC count of 934 cells/µL or more (sensitivity 0.82 [95% CI 0.71 to 0.89], specificity 0.82 [95% CI 0.71 to 0.89]) as well as a PMN percentage of at least 52% (sensitivity 0.82 [95% CI 0.71 to 0.89] and specificity 0.78 [95% CI 0.67 to 0.86]. We found no difference between the AUCs for the WBC count and the PMN percentage (0.87 [95% CI 0.79 to 0.96] versus 0.84 [95% CI 0.73 to 0.95]. Comparing the sensitivities and specificities of the synovial fluid WBC count and PMN percentage proposed by other authors, we find that a PMN percentage more than 52% showed better predictive value than previously reported.

CONCLUSION

Based on our findings, we believe that patients with WBC counts of at least 934 and PMN percentage of 52% or more should not undergo reimplantation but rather a repeat debridement, as their risk of persistent or recurrent PJI appears prohibitively high. The accuracy of the proposed cutoffs is better than previously reported.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Systematic review of risk prediction studies in bone and joint infection: are modifiable prognostic factors useful in predicting recurrence?

Background: Classification systems for orthopaedic infection include patient health status, but there is no consensus about which comorbidities affect prognosis. Modifiable factors including substance use, glycaemic control, malnutrition and obesity may predict post-operative recovery from infection. Aim: This systematic review aimed (1) to critically appraise clinical prediction models for individual prognosis following surgical treatment for orthopaedic infection where an implant is not retained; (2) to understand the usefulness of modifiable prognostic factors for predicting treatment success. Methods: EMBASE and MEDLINE databases were searched for clinical prediction and prognostic studies in adults with orthopaedic infections. Infection recurrence or re-infection after at least 6 months was the primary outcome. The estimated odds ratios for the primary outcome in participants with modifiable prognostic factors were extracted and the direction of the effect reported. Results: Thirty-five retrospective prognostic cohort studies of 92 693 patients were included, of which two reported clinical prediction models. No studies were at low risk of bias, and no externally validated prediction models were identified. Most focused on prosthetic joint infection. A positive association was reported between body mass index and infection recurrence in 19 of 22 studies, similarly in 8 of 14 studies reporting smoking history and 3 of 4 studies reporting alcohol intake. Glycaemic control and malnutrition were rarely considered. Conclusion: Modifiable aspects of patient health appear to predict outcomes after surgery for orthopaedic infection. There is a need to understand which factors may have a causal effect. Development and validation of clinical prediction models that include participant health status will facilitate treatment decisions for orthopaedic infections.

Perioperative management of elderly patients with osteoarthritis requiring total knee arthroplasty

Knee osteoarthritis is a common arthritic disease which mainly affects the elderly (≥65 years old) population. As a result of the cartilage degeneration, it can cause a significant amount of pain and functional limitation. In patients who are refractory to conservative management, total knee arthroplasty is being utilised as the last resort in management. In this review, we discuss the perioperative management of elderly patients with osteoarthritis requiring total knee arthroplasty.

Preoperative Allergy Testing for Patients Reporting Penicillin and Cephalosporin Allergies is Cost-Effective in Preventing Infection after Total Knee and Hip Arthroplasty

BACKGROUND

Routine preoperative allergy testing in patients reporting penicillin and cephalosporin allergies increases the number able to receive cefazolin, which should reduce the risk of infection after total knee and hip arthroplasty (TKA/THA), but it remains unclear whether this practice is cost-effective. Using a break-even analysis, we calculated the cost-effectiveness of routine preoperative allergy testing for infection prevention in total joint arthroplasty patients reporting penicillin and cephalosporin allergies.

METHODS

The cost of a penicillin allergy evaluation, the cost of revision arthroplasty for prosthetic joint infection (PJI), and baseline rates of PJI in patients receiving a noncefazolin antibiotic in the perioperative period were derived from existing literature. A break-even economic model using these variables was constructed to calculate the absolute risk reduction (ARR) in infection rate needed for preoperative allergy testing to be cost-effective. The number needed to treat (NNT) was calculated from the ARR.

RESULTS

Preoperative allergy testing before TKA and THA in patients reporting penicillin and cephalosporin allergies was cost-effective if the initial infection rate decreased by an ARR of 0.810% (NNT = 123) and 0.655% (NNT = 153) for TKA and THA, respectively. Cost-effectiveness was maintained with varying allergy consultation costs, infection rates, and costs associated with PJI treatment.

CONCLUSION

Routine preoperative allergy testing and clearance are cost-effective infection prevention strategies among patients reporting penicillin and cephalosporin allergies in the setting of elective joint arthroplasty. Widespread adoption of this practice may considerably reduce the economic and societal burden associated with prosthetic infections.

Difficult to treat: are there organism-dependent differences and overall risk factors in success rates for two-stage knee revision?

OBJECTIVES

Failure after two-stage procedure for periprosthetic joint infection (PJI) is a rare, but devastating complication. Some authors assume a correlation of underlying organisms and recurrence rate. Methicillin-resistant Staphylococci (MRS) and other organisms (quinolone-resistant Gram-negative bacteria, rifampicin-resistant Staphylococcus, Enterococcus, and Candida) are meant to be "difficult to treat" (DTT) with an inferior outcome for two-stage revision. In addition to the type of bacteria, some more risk factors seem to be present. The aim of this study was (1) to detect a difference of reinfection rates between reinfection-causing groups of bacteria ["difficult to treat" (DTT), "easy to treat" (ETT) and methicillin-resistant staphylococci (MRS)] after a two-stage procedure, and (2) find overall risk factors for reinfection in a standardized long (spacer insertion for at least 6 weeks) two-stage procedure for periprosthetic knee infection.

METHODS

One hundred and thirty-seven two-stage revisions for periprosthetic knee infection were performed at one tertiary referral center. Finally, 96 patients could be included for analyses. Possible risk factors (comorbidities, prior surgery, etc.) and the types of organisms were documented. Quinolone-resistant Gram-negative bacteria, rifampicin-resistant Staphylococcus, Enterococcus, and Candida were classified as "difficult to treat" (DTT). Methicillin-resistant Staphylococci were summarized as "MRS", all other organism are summarized as "easy to treat" (ETT). Statistical analyses included univariate analysis (t test, Fisher's exact test, Chi square test) and logistic regression analysis.

RESULTS

There were no statistical significant differences in recurrent infection rates between organism groups (DTT vs. ETT, p = 0.674; DTT vs. MRS, p = 0.705; ETT vs. MRS, p = 0.537). Risk factors seem to be "need of revision after first stage" (p = 0.019, OR 5.62) or completed second stage (p = 0.000, OR 29.07), numbers of surgeries (p = 0.028) and alcohol abuse (p = 0.019, OR 5.62).

CONCLUSIONS

Revision needed during or after a two-stage exchange, numbers of surgeries and alcohol abuse are risk factors for recurrence, a different recurrence rates between organism-groups cannot be shown. The absence of significant differences in recurrence rates points to the importance of the individuality of each periprosthetic infection case: a reduction of necessary surgeries (with a thorough debridement, appropriate antibiotic addition to spacers) and the control of comorbidities (alcohol abuse) appear to be essential components of a two-stage exchange.

Risk factors of uncontrolled periprosthetic knee joint infection after two-stage reimplantation

BACKGROUND

Periprosthetic infection after total knee arthroplasty is a challenging problem, and physicians should identify risk factors to decrease recurrence. However, risk factors for reinfection with two-stage reimplantation have not yet been well established. The purpose of this study was to assess treatment outcomes of subsequent two-stage knee reimplantation and identify risk factors for uncontrolled periprosthetic knee joint infections.

METHODS

We retrospectively reviewed 70 knees diagnosed with a periprosthetic knee joint infection treated with two-stage reimplantation between September 2011 and October 2016 at our institution. Patients in the controlled infection group (group C) required no further medication or surgical treatment within 2 years after reimplantation. Patients in the uncontrolled infection group (group U) displayed symptoms of active infection after resection arthroplasty or were reinfected after two-stage reimplantation. We compared group C and group U, and analyzed potential risk factors for uncontrolled prosthetic joint infection (PJI).

RESULTS

Of 70 knees included in this analysis, 53 (75.7%) were clinically deemed free from infection at the latest follow-up. The remaining 17 knees (24.3%) required additional surgical procedures after two-stage reimplantation. Demographics were not statistically significantly different between the two groups. Wound complications were statistically more frequent in group U (p = 0.030). Pre-reimplantation C-reactive protein (CRP) was statistically different between groups C and U (0.44 and 1.70, respectively, p = 0.025). Among the cultured microorganisms, fungus species were statistically more frequently detected in group U compared with group C (p = 0.031).

CONCLUSIONS

The reinfection rate of our two-stage reimplantation protocol was 24.3% in the included cases. Wound complications, higher pre-reimplantation CRP levels, and fungus species were statistically more common in group U compared with group C. Our findings will help in counseling patients and physicians to understand that additional caution may be required when treating PJI if the aforementioned risk factors are present.

LEVEL OF EVIDENCE

IV, case series.

Predictors of Treatment Failure for Hip and Knee Prosthetic Joint Infections in the Setting of 1- and 2-Stage Exchange Arthroplasty: A Multicenter Retrospective Cohort

Background

Prosthetic hip and knee joint infections (PJIs) are challenging to eradicate despite prosthesis removal and antibiotic therapy. There is a need to understand risk factors for PJI treatment failure in the setting of prosthesis removal.

Methods

A retrospective cohort of individuals who underwent prosthesis removal for a PJI at 5 hospitals in Toronto, Canada, from 2010 to 2014 was created. Treatment failure was defined as recurrent PJI, amputation, death, or chronic antibiotic suppression. Potential risk factors for treatment failure were abstracted by chart review and assessed using a Cox proportional hazards model.

Results

A total of 533 individuals with prosthesis removal were followed for a median (interquartile range) of 814 (235–1530) days. A 1-stage exchange was performed in 19% (103/533), whereas a 2-stage procedure was completed in 88% (377/430). Treatment failure occurred in 24.8% (132/533) at 2 years; 53% (56/105) of recurrent PJIs were caused by a different bacterial species. At 4 years, treatment failure occurred in 36% of 1-stage and 32% of 2-stage procedures (P = .06). Characteristics associated with treatment failure included liver disease (adjusted hazard ratio [aHR], 3.12; 95% confidence interval [CI], 2.09–4.66), the presence of a sinus tract (aHR, 1.53; 95% CI, 1.12–2.10), preceding debridement with prosthesis retention (aHR, 1.68; 95% CI, 1.13–2.51), a 1-stage procedure (aHR, 1.72; 95% CI, 1.28–2.32), and infection due to Gram-negative bacilli (aHR, 1.35; 95% CI, 1.04–1.76).

Conclusions

Failure of PJI therapy is common, and risk factors are not easily modified. Improvements in treatment paradigms are needed, along with efforts to reduce orthopedic surgical site infections.

Impact of patient comorbidities on surgical site infection within 90 days of primary and revision joint (hip and knee) replacement

BACKGROUND

The frequency of primary and revision total knee and hip replacements (pTKRs, rTKRs, pTHRs, and rTHRs, respectively) is increasing in the United States due to demographic changes. This study evaluated the impact of preoperative patient and clinical factors on the risk of surgical site infection (SSI) within the 90-day period after primary and revision total joint replacements (TJR).

METHODS

A retrospective observational cohort study was designed using the IBM MarketScan and Medicare databases, 2009-2015. Thirty-four comorbidities were assessed for all patients, and multivariable logistic regression models were used to evaluate factors associated with higher odds of SSI after adjusting for other patient and clinical preoperative conditions.

RESULTS

The study included a total of 335,134 TKRs and 163,547 THRs. SSI rates were 15.6% and 8.6% after rTKR and rTHR, respectively, compared with 2.1% and 2.1% for pTKR and pTHR, respectively. Comorbidities with the greatest adjusted effect on SSI across all TJRs were acquired immunodeficiency syndrome (odds ratio [OR], 1.58; 95% confidence interval [CI], 1.06-2.34; P = .0232), paralysis (OR, 1.56; 95% CI, 1.26-1.94; P < .0001), coagulopathy (OR, 1.48; 95% CI, 1.36-1.62; P < .0001), metastatic cancer (1.48; 95% CI, 1.24-1.76; P < .0001), and congestive heart failure (OR, 1.39; 95% CI, 1.30-1.49; P < .0001).

CONCLUSIONS

SSI occurred most commonly among patients after revision TJR and were related to many patient comorbidities, including diabetes, congestive heart failure, and coagulopathy, which were significantly associated with a higher risk of SSI after TJR.

Evaluation of early wound leakage as a risk factor for prosthetic joint infection

BACKGROUND AND PURPOSE

Prosthetic joint infection (PJI) is a serious complication resulting from total knee arthroplasty (TKA) or total hip arthroplasty (THA). In this study, patients with a PJI are compared with patients with an uncomplicated postoperative course to identify relevant risk factors for PJI.

METHODS

A matched case-control study was performed with patients undergoing fast-track, elective unilateral TKA or THA. The following data were collected: demographics, surgery-related characteristics (perioperative blood loss, use of cement, body temperature), and postoperative characteristics (hematoma formation, wound leakage, blood transfusion, length of stay [LOS]).

CONCLUSIONS

When the PJI group was compared with the control group, there was significantly more wound leakage during hospital stay (88% vs. 36%, p = .001) and early wound dressing changes in the first 3 days after surgery (88% vs. 40%, p = .002). Hematoma formation was observed more in the PJI patients group (44% vs. 10%, p = .005). A trend test revealed a significant association between the total number of wound dressing changes and development of PJI (p < .001); 72% of PJI patients had a length of stay of ≥4 days compared with 34% of controls (odds ratio 10.5; 95% CI [2.1-52.3]; p = .004).

IMPLICATIONS FOR PRACTICE

Early postoperative wound drainage and hematoma formation directly correlate with PJI. This resulted in a significantly higher number of dressing changes and longer LOS. The nurse practitioner has a central role in postoperative care and is the first to recognize signs of an adverse postoperative clinical course.

A cost-effectiveness analysis of mupirocin and chlorhexidine gluconate for Staphylococcus aureus decolonization prior to hip and knee arthroplasty in Alberta, Canada compared to standard of care

Background

While decolonization of Staphylococcus aureus reduces surgical site infection (SSI) rates following hip and knee arthroplasty, its cost-effectiveness is uncertain. We sought to examine the cost-effectiveness of a decolonization protocol for Staphylococcus aureus prior to hip and knee replacement in Alberta compared to standard care – no decolonization.

Methods

Decision analytic models and a probabilistic sensitivity analysis were used for a cost-effectiveness analysis, with the effectiveness of decolonization based on a large published pre- and post- intervention trial. The primary outcomes of the models were infections prevented and health care costs. We modelled the cost-effectiveness of decolonization in a hypothetical cohort of adult patients undergoing hip and knee replacement in Alberta, Canada. Information on the incidence of complex surgical site infections (SSIs), as well as the cost of care for patients with and without SSIs was taken from a provincial infection control database, and health administrative data.

Results

Use of the decolonization bundle was cost saving compared to usual care ($153/person), and resulted in 16 complex Staphylococcus aureus SSIs annually as opposed to 32 (with approximately 8000 hip or knee arthroplasties performed). The probabilistic sensitivity analysis demonstrated that the majority (84%) of the time the decolonization bundle was cost saving. The model was robust to one-way sensitivity analyses conducted within plausible ranges. There were small upfront costs associated with using a decolonization protocol, however, this model demonstrated cost savings over one year. In a Markov model that considered the impact of a decolonization bundle over a lifetime as it pertained to the need for subsequent joint replacements and patient quality of life, the bundle still resulted in cost savings ($161/person).

Conclusions

Decolonization for Staphylococcus aureus prior to hip and knee replacements resulted in cost savings and fewer SSIs, and should be considered prior to these procedures.

Electronic supplementary material

The online version of this article (10.1186/s13756-019-0568-5) contains supplementary material, which is available to authorized users.

Use of Closed Incisional Negative Pressure Wound Therapy After Revision Total Hip and Knee Arthroplasty in Patients at High Risk for Infection: A Prospective, Randomized Clinical Trial

BACKGROUND

Continuous wound drainage after arthroplasty can lead to the development of a periprosthetic joint infection. Closed incisional negative pressure wound therapy (ciNPWT) has been reported to help alleviate drainage and other wound complications. The purpose of this prospective randomized controlled trial is to compare the use of ciNPWT with our standard of care dressing in revision arthroplasty patients who were at high risk to develop wound complications.

METHODS

A total of 160 patients undergoing elective revision arthroplasty were prospectively randomized to receive either ciNPWT or a silver-impregnated occlusive dressing after surgery in a single institution. Patients were included if they had at least 1 risk factor for developing wound complication(s): wound complication, readmission, and reoperation rates were collected at 2, 4, and 12 weeks postoperatively.

RESULTS

The postoperative wound complication rate was significantly higher in the control cohort compared to the ciNPWT cohort (19 [23.8%] vs 8 [10.1%], P = .022). There was no significant difference between the control and ciNPWT cohorts in terms of readmissions (19 [23.8%] vs 16 [20.3%], P = .595). Reoperation rate was higher in controls compared to ciNPWT patients (10 [12.5%] vs 2 [2.5%], P = .017). After adjusting for the history of a prior periprosthetic joint infection and inflammatory arthritis, the ciNPWT cohort had a significantly decreased wound complication rate (odds ratio 0.28, 95% confidence interval 0.11-0.68).

CONCLUSION

ciNPWT may decrease the rate of postoperative wound complications in patients who are at an increased risk of such wound issues after revision arthroplasty.

Reconsidering Strategies for Managing Chronic Periprosthetic Joint Infection in Total Knee Arthroplasty: Using Decision Analytics to Find the Optimal Strategy Between One-Stage and Two-Stage Total Knee Revision

BACKGROUND

Periprosthetic joint infection (PJI) following total knee arthroplasty is a growing concern, as the demand for total knee arthroplasty (TKA) expands annually. Although 2-stage revision is considered the gold standard in management, there is substantial morbidity and mortality associated with this strategy. One-stage revision is associated with lower mortality rates and better quality of life, and there has been increased interest in utilizing the 1-stage strategy. However, surgeons are faced with a difficult decision regarding which strategy to use to treat these infections, considering uncertainty with respect to eradication of infection, quality of life, and societal costs with each strategy. The purpose of the current study was to use decision analysis to determine the optimal decision for the management of PJI following TKA.

METHODS

An expected-value decision tree was constructed to estimate the quality-adjusted life-years (QALYs) and costs associated with 1-stage and 2-stage revision. Two decision trees were created: Decision Tree 1 was constructed for all pathogens, and Decision Tree 2 was constructed solely for difficult-to-treat infections, including methicillin-resistant infections. Values for parameters in the decision model, such as mortality rate, reinfection rate, and need for additional surgeries, were derived from the literature. Medical costs were derived from Medicare data. Sensitivity analysis determined which parameters in the decision model had the most influence on the optimal strategy.

RESULTS

In both decision trees, the 1-stage strategy produced greater health utility while also being more cost-effective. In the Monte Carlo simulation for Decision Trees 1 and 2, 1-stage was the dominant strategy in about 85% and 69% of the trials, respectively. Sensitivity analysis showed that the reinfection and 1-year mortality rates were the most sensitive parameters influencing the optimal decision.

CONCLUSIONS

Despite 2-stage revision being considered the current gold standard for infection eradication in patients with PJI following TKA, the optimal decision that produced the highest quality of life was 1-stage revision. These results should be considered in shared decision-making with patients who experience PJI following TKA.

LEVEL OF EVIDENCE

Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

GEDOS-SECOT consensus on the care process of patients with knee osteoarthritis and arthoplasty

OBJECTIVE

To develop recommendations on the evaluation and management procedure in patients undergoing total knee replacement based on best evidence and the experience of a panel of experts.

METHODS

A multidisciplinary group of 12 experts was selected that defined the scope, users and the document parts. Three systematic reviews were performed in patients undergoing knee replacement: (i)efficacy and safety of fast-tracks; (ii)efficacy and safety of cognitive interventions in patients with catastrophic pain, and (iii) efficacy and safety of acute post-surgical pain management on post-surgical outcomes. A narrative review was conducted on the evaluation and management of pain sensitization, and about the efficacy and safety of pre-surgical physiotherapy. The experts generated the recommendations and explicative text. The level of agreement was evaluated in a multidisciplinary group of 85 experts with the Delphi technique. The level of evidence was established as well for each recommendation.

RESULTS

A total of 20 recommendations were produced. An agreement higher than 80% was reached in all of them. We found the highest agreement on the need for a full discharge report, on providing proper information about the process and on following available guidelines.

CONCLUSIONS

There is consensus among professionals involved in the management of patients undergoing total knee replacement, in that it is important to protocolize the replacement process, performing a proper, integrated and coordinated patient evaluation and follow-up, paying special attention to the surgical procedure and postoperative period.

Eradication rates, risk factors, and implant selection in two-stage revision knee arthroplasty: a mid-term follow-up study

Background

Two-stage revision (TSR) knee arthroplasty is an established treatment, but failure to control infection still occurs in 4–50 % of cases. The aim of this study was to assess the infection eradication rate, risk factors for failure, and the clinical outcome after two-stage revision knee arthroplasty.

Methods

This retrospective study included 59 patients who had undergone at least one two-stage revision procedure due to periprosthetic joint infection (PJI). Demographic data, comorbidities, types of implant, and complications were analyzed. Univariate and multivariate logistic regression analysis were used to identify risk factors for failure.

Results

The infections were controlled in 55 patients (93.2 %). The follow-up period was 4.1 (±2.7) years. Infection control was achieved after the first TSR in 42 patients (71.2 %) and after the second TSR in 13 (76.5 %). The percentage of arthrodesis procedures in patients with infection control increased from 16.75 % after one TSR to 69.2 % after two TSRs. Multivariate logistic regression analysis identified body mass index (BMI) (odds ratio 1.22; 95 % confidence intervals, 1.07 to 1.40; p = 0.004) and smoking (OR 21.52; 95 % CI, 2.60 to 178.19; p = 0.004) as risk factors for failure.

Conclusions

Two-stage revision protocols can achieve acceptable results even after a second procedure. It is still unclear whether the choice of implant influences failure rates. Risk factors for failure after two-stage revision were identified. Studies with larger sample sizes are needed in order to support these findings and identify further risk factors. To reduce failure rates, programs should be established to treat or minimize risk factors in patients with PJI.