Decreasing time trend in SSI incidence for orthopaedic procedures: surveillance matters!

Surveillance for surgical site infections developed during hospital stay & after discharge: A multicentric study

Background & objectives Surgical site infections (SSIs) are among the most prevalent healthcare-associated infections (HCAIs). They cause significant morbidity, leading to excess health expenditures and increased length of hospital stay. Despite a high population burden, data on post-discharge SSIs is lacking from low-and middle-income countries (LMICs). There is no existing surveillance system of SSIs in India that covers the post-discharge period. Therefore, we proposed a multicentric analysis to estimate the proportion and identify the risk factors associated with SSIs occurring during hospital stay and after discharge. Methods SSI Surveillance was conducted in three hospitals in different parts of India according to the Centers for Disease Control and Prevention (CDC) guidelines (30 days-6 months). An indigenous database was developed for data entry and analysis. Logistic regression analysis was performed to test for an association between SSI and potential risk factors. Results A total of 161 out of 3090 patients acquired SSI, resulting in a 5.2 per cent SSI incidence. Debridement surgery, which was carried out with either an amputation, open reduction internal fixation surgery (ORIF), or closed reduction internal fixation (CRIF) surgery, had the highest SSI rate (54.2%). Clean, polluted wound class and surgeries lasting longer than 120 minutes were substantially linked to an increased risk of SSI. Interpretation & conclusions Post-discharge surveillance helped with the detection of 66 per cent of SSI cases. Combination surgeries were seen to increase the risk of SSIs in patients.

The Effect of American Society of Anesthesiologists Score and Operative Time on Surgical Site Infection Rates in Major Abdominal Surgeries

BACKGROUND

The objective of this study was to evaluate the influence of two crucial variables, the American Society of Anesthesiologists (ASA) score and operative time, on the occurrence of surgical site infections (SSIs) in the context of major abdominal surgical procedures.

METHODOLOGY

A cross-sectional research study involved patients undergoing various gastrointestinal surgical procedures. Surgical details, procedure duration, and ASA score were meticulously documented. Patients were observed for surgical site infections (SSIs) during their inpatient stay until discharge. Following their discharge, patients were monitored in the outpatient department for a minimum of 30 days post-surgery, and those who underwent mesh procedures were observed for one year.

RESULTS

In the overall study population, surgical site infections were identified in 42 cases, constituting 6.7%. There was a significant association between ASA grade and the incidence of surgical site infections (p=0.001), indicating a higher prevalence of infections in cases with elevated ASA grades. Furthermore, a statistically significant association exists between the average duration of surgery and the occurrence of surgical site infections (p=0.001). The mean surgery duration for cases with infections is reported as 206.33 min, with a standard deviation of 103.73, while for cases without infections, the mean duration is 99.72 min, with a standard deviation of 79.71. In the multivariate analysis, it was found that an ASA score of 3 or higher and operative time exceeding 90 min were identified as independent factors for predicting the likelihood of surgical site infections.

CONCLUSION

 The significant associations identified between the American Society of Anesthesiologists (ASA) grade, average surgery duration, and SSIs underscore the importance of comprehensive preoperative assessment and procedural management in infection prevention.

Rates of Antimicrobial Resistance With Extended Oral Antibiotic Prophylaxis After Total Joint Arthroplasty

Background

There is increased interest and utilization of extended oral antibiotic prophylaxis (EOAP) following primary and revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs). The purpose of this study was to look for potential associations between EOAP and differential rates of antimicrobial resistance or epidemiology of organisms causing periprosthetic joint infection (PJI) following primary and aseptic revision THAs/TKAs.

Methods

Patients who developed PJI following a primary or aseptic revision TKA/THA at a single institution from 2009 to 2020 were retrospectively identified. Patients who received at least 7 days of EOAP following the surgery were noted. Rates of antimicrobial resistance were compared between standard antibiotic prophylaxis and EOAP cohorts using the Fisher's exact test.

Results

One hundred twenty-eight cultures were obtained from 119 patients with PJI. Fourty-four cases (37%) developed PJI after EOAP. Staphylococcus aureus was the most frequently isolated organism (30% of all cultures; 78% were methicillin-sensitive). Rates of antimicrobial resistance were similar between standard antibiotic prophylaxis and EOAP cohorts in all but 2 instances: Increased resistance to erythromycin and trimethoprim-sulfamethoxazole was observed in coagulase-negative Staphylococci isolates in the EOAP cohort (89% vs 21%, P < .01; 44% vs 0%, P = .02). An increased frequency of gram-negative organisms was observed in the EOAP group (22% vs 8%, P = .03).

Conclusions

Rates of antimicrobial resistance were not significantly different between EOAP and standard antibiotic prophylaxis cohorts except in coagulase-negative Staphylococci. The increased frequency of gram-negative infections was present in the EOAP cohort. Larger, multicenter studies are needed to better understand the impact of EOAP on antimicrobial resistance and PJI epidemiology.

Level of Evidence

Level III; retrospective cohort study.

Total knee arthroplasty in the past three decades: Trends in patient characteristics and implant survivorship

OBJECTIVE

To explore the trends in patient characteristics and implant survivorship (IS) for primary total knee arthroplasty (TKA) over the past three decades.

METHODS

This retrospective study enrolled a total of 635 knees who underwent TKA from 1985 to 2014. They were divided into three groups: group A, 125 knees in 1985-1994; group B, 203 knees in 1995-2004; and group C, 307 knees A in 2005-2014. The patient characteristics and IS were compared.

RESULTS

The mean age of patients undergoing TKA was getting older: 65.3 ± 9.7, 69.1 ± 10.0, and 74.6 ± 8.4 years, in groups A, B, and C, respectively (p = .001). The proportion of patients <60 years old with RA decreased (p < .001), whereas that of patients ≥ 80 years old with OA increased dramatically, it was 7.0%, 14.5%, and 32.0% in groups A, B, and C, respectively (p < .001). The IS free from infection was over 98% in all groups. Alternatively, the IS free from aseptic loosening become better, it was 83.7%, 95.2%, and 98.2% in groups A, B, and C, respectively (p = .014).

CONCLUSIONS

From these trends, we can estimate that the number of patients undergoing TKA will further increase in the future in an aging society.

Surveillance for surgical site infections in orthopedic trauma surgeries at an Indian hospital

PURPOSE

Surgical site infections (SSIs) are one of the most common, causing substantial morbidity, mortality and are highly cost-effective means of reducing healthcare associated infections rates in health care set-ups. In India, there is no existing system for systematic surveillance of SSIs, encompassing post-discharge period.

METHODS

An indigenous SSI e-surveillance software was developed. Patients developing SSI as per standard definitions were included in the study. A denominator form and a case report form were filled for each case of SSI detected. The microbiological diagnosis was done as per standard methods. Logistic regression analysis was used to test for association of SSI and risk factors and determining the prevalence odds ratios.

RESULTS

Of the total of 850 patients enrolled in the SSI surveillance, 47 (5.5%) developed SSI. Most patients (490/850, 58%) underwent the open reduction internal fixation (ORIF) and also developed an SSI (33/490, 6.7%). Clean contaminated wound class and Dressing were found to be associated with increased risk of SSI significantly, Also increase in the length of stay was found to be associated with increased risk of SSI significantly. High antimicrobial resistance was observed in the microbial isolates recovered from SSIs. Patients who developed SSI had longer hospital stays.

CONCLUSIONS

Our study has been the first systematic surveillance effort in India, where patients were followed up till six months post surgeries. This pilot study was later expanded to other Indian hospitals. This network of SSI-Surveillance will lay the foundation for initiation of SSI-surveillance across the country.

Comparing Relative Value Units among Shoulder Arthroplasty, Hemiarthroplasty, and ORIF for Proximal Humerus Fractures in the Elderly: Which is Most Worth Your Time?

Background

Relative value units (RVUs) are assigned to Current Procedural Technology (CPT) codes and give relative economic values to the services physicians provide. This study compared the RVU reimbursements for the surgical options of proximal humerus fractures in the elderly, which include arthroplasty (reverse [RSA] and total [TSA]), hemiarthroplasty (HA), and open reduction and internal fixation (ORIF).

Methods

Using the National Surgical Quality Improvement Program, a total of 1,437 patients of at least 65 years of age with proximal humerus fractures between 2008 and 2016 were identified. Of those, 259 underwent RSA/TSA (CPT code 23472), 418 underwent HA (CPT codes 23470 and 23616), and 760 underwent ORIF (CPT code 23615). Univariate analysis compared RVU per minute, reimbursement rate, and the average annual revenue across cohorts based on respective operative times.

Results

RSA/TSA generated a mean RVU per minute of 0.197 (SD 0.078; 95%CI [0.188, 0.207]), which was significantly greater than the mean RVU per minute for 23470 HA (0.156; SD 0.057; 95%CI [0.148, 0.163]), 23616 HA (0.166; SD 0.065; 95%CI [0.005, 0.156]), and ORIF (0.135; SD 0.048; 95%CI [0.132, 0.138]; P<0.001). This converted to respective reimbursement rates of $6.97/min (SD 2.78; 95%CI [6.63, 7.31]), $5.48/min (SD 2.05; 95%CI [5.22, 5.74]), $5.83/min (SD 2.28; 95%CI [5.49, 6.16]) and $4.74/min (SD 1.69; 95%CI [4.62, 4.87]). After extrapolation, respective average annual revenues were $580,386, $456,633, $475,077, and $395,608.

Conclusion

RSA/TSA provides significantly greater reimbursement rates compared to HA and ORIF. Orthopaedic surgeons can use this information to optimize daily procedural cost-effectiveness in their practices.

Are conventional microbiological diagnostics sufficiently expedient in the era of rapid diagnostics? Evaluation of conventional microbiological diagnostics of orthopedic implant-associated infections (OIAI)

Background and purpose - In a time when rapid diagnostics are increasingly sought, conventional procedures for detection of microbes causing orthopedic implant-associated infections (OIAI) seem extensive and time-consuming, but how extensive are they? We assessed time to (a) pathogen identification, (b) antibiotic susceptibility patterns, and (c) targeted antibiotic treatment using conventional microbiological diagnostics of OIAI in a consecutive series of patients.Patients and methods - Consecutive patients aged ≥18 years undergoing first revision surgery for acute OIAI, including prosthetic joints, fracture, and osteotomy implants, in 2017-2018 at Akershus University Hospital (Ahus), Norway were included. Information regarding microbiological diagnostics and clinical data was collected retrospectively from the hospital's diagnostic and clinical databases.Results - 123 patients fulfilled the inclusion criteria. Median time to pathogen identification was 2.5 days and to antibiotic treatment recommendations was 3.5 days. The most common pathogens were S. aureus (52%) and S. epidermidis (15%). Cultures were inconclusive in 11% of the patients. Of the 109 patients with culture-positive results, antibiotic treatment was changed in 66 (61%) patients within a median of 4 days (0-24) after the recommendation was given.Interpretation - Conventional microbiological diagnostics of OIAI is time-consuming, taking days of culturing. Same-day diagnostics would vastly improve treatment efficacy, but is dependent on rapid implementation by clinicians of the treatment recommendations given by the microbiologist.

The Impact of EBM-Manufactured Ti6Al4V ELI Alloy Surface Modifications on Cytotoxicity toward Eukaryotic Cells and Microbial Biofilm Formation

Electron beam melting (EBM) is an additive manufacturing technique, which allows forming customized implants that perfectly fit the loss of the anatomical structure of bone. Implantation efficiency depends not only on the implant's functional or mechanical properties but also on its surface properties, which are of great importance with regard to such biological processes as bone regeneration or microbial contamination. This work presents the impact of surface modifications (mechanical polishing, sandblasting, and acid-polishing) of EBM-produced Ti6Al4V ELI implants on essential biological parameters. These include wettability, cytotoxicity toward fibroblast and osteoblast cell line, and ability to form biofilm by Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Obtained results indicated that all prepared surfaces exhibited hydrophilic character and the highest changes of wettability were obtained by chemical modification. All implants displayed no cytotoxicity against osteoblast and fibroblast cell lines regardless of the modification type. In turn, the quantitative microbiological tests and visualization of microbial biofilm by means of electron microscopy showed that type of implant's modification correlated with the species-specific ability of microbes to form biofilm on it. Thus, the results of the presented study confirm the relationship between such technological aspects as surface modification and biological properties. The provided data are useful with regard to applications of the EBM technology and present a significant step towards personalized, customized implantology practice.

DNA extraction of microbial DNA directly from infected tissue: an optimized protocol for use in nanopore sequencing

Identification of bacteria causing tissue infections can be comprehensive and, in the cases of non- or slow-growing bacteria, near impossible with conventional methods. Performing shotgun metagenomic sequencing on bacterial DNA extracted directly from the infected tissue may improve time to diagnosis and targeted treatment considerably. However, infected tissue consists mainly of human DNA (hDNA) which hampers bacterial identification. In this proof of concept study, we present a modified version of the Ultra-Deep Microbiome Prep kit for DNA extraction procedure, removing additional human DNA. Tissue biopsies from 3 patients with orthopedic implant-related infections containing varying degrees of Staphylococcus aureus were included. Subsequent DNA shotgun metagenomic sequencing using Oxford Nanopore Technologies' (ONT) MinION platform and ONTs EPI2ME WIMP and ARMA bioinformatic workflows for microbe and antibiotic resistance genes identification, respectively. The modified DNA extraction protocol led to an additional ~10-fold reduction of human DNA while preserving S. aureus DNA. Including the DNA sequencing and bioinformatics analyses, the presented protocol has the potential of identifying the infection-causing pathogen in infected tissue within 7 hours after biopsy. However, due to low number of S. aureus reads, positive identification of antibiotic resistance genes was not possible.

Rapid diagnostics of orthopedic implant-associated infections using Unyvero ITI implant and tissue infection application is not optimal for Staphylococcus species identification

Objectives

This pilot study aimed to compare the commercial Unyvero ITI multiplex PCR application (U-ITI, Curetis GmbH) with conventional culturing concerning (a) detection of pathogens, (b) time to detection of pathogens and (c) time to and quality of antibiotic treatment recommendation in diagnostics of orthopedic implant-associated infections (OIAI).

Results

72 tissue biopsies from 15 consecutive patients with deep OIAI infections were analyzed with conventional culturing including phenotypic antibiotic susceptibility testing and the U-ITI. U-ITI showed lower sensitivity than conventional culturing concerning detection of pathogens (73% vs 93%). 4/15 patients would have been given false negative results by U-ITI, all of which were culture-positive for Staphylococcus species. Median time to detection of pathogens was 47 h and antibiotic resistance 89 h by conventional methods compared to 13.5 h with the U-ITI. The U-ITI did not detect antibiotic resistance, whereas conventional culturing showed resistance to antibiotics covered by the U-ITI panel in 2 patients. Time to detection of pathogens was improved, but the detection limit for staphylococci was unsatisfactory. Although the time to antibiotic treatment recommendation was significantly reduced, the U-ITI would have resulted in incorrect antibiotic recommendation in 2 patients. Our data do not support use of this assay in diagnostics.

Extended Antibiotic Prophylaxis Confers No Benefit Following Aseptic Revision Total Hip Arthroplasty: A Matched Case-Controlled Study

BACKGROUND

Administration of perioperative antibiotic prophylaxis is one of the most important practices for prevention of periprosthetic joint infection (PJI) in patients undergoing total hip arthroplasty (THA). It is common to continue perioperative antibiotic prophylaxis for 48 hours or longer in patients undergoing revision arthroplasty, until results of intraoperative culture samples become available. However, the utility of this practice remains unclear. We examined whether extended antibiotic prophylaxis following aseptic revision THA reduces the risk of subsequent PJI.

METHODS

We retrospectively reviewed records of patients undergoing aseptic revision THA between January 2000 and December 2015. At our institution, some surgeons administer prophylactic antibiotics to revision patients for only 24 hours while others prefer to extend until intraoperative culture results become available. We matched 209 patients undergoing revision THA who received extended antibiotic prophylaxis (>24 hours) in a 1:1 ratio with 209 patients receiving standard antibiotic prophylaxis (≤24 hours). The matching criteria were age, sex, body mass index, Charlson comorbidity index, and operative time.

RESULTS

The incidence of subsequent PJI was 4.8% in patients receiving extended antibiotic prophylaxis vs 2.4% in patients receiving standard. After adjusting for all cofounders and using multivariate logistic regression, the administration of extended prophylactic antibiotics did not reduce the incidence of subsequent infection. When stratified by postoperative antibiotic regimens, the 2 groups had similar infection-free implant survival rate (95.2% in extended and 97.6% in standard).

CONCLUSION

It appears that extending perioperative prophylactic antibiotics until intraoperative culture results become available in patients undergoing revision THA for aseptic failures does not provide any additional benefit in terms of reducing the risk of subsequent PJI.

Third day laboratory follow-up: mandatory for surgical site infections of tibial plateau fractures

INTRODUCTION

Tibial plateau fractures are common fractures in adults and can be extremely challenging for surgeons. State-of-the-art therapy is open reduction and internal fixation (ORIF), although major complications of ORIF are surgical site infections (SSIs). This is especially critical on the proximal tibia, which is only sparsely covered by soft tissue and has a close relation to the knee joint. We analyzed SSIs after ORIF to correlate established laboratory parameters to the occurrence of SSIs.

METHODS

A monocentric case-control study in a Level 1 Trauma Center was conducted. Data were acquired from electronic medical records from 2011 until 2016. White blood cell count (WBC) and C-reactive protein (CRP) were used as laboratory parameters and statistically analyzed.

RESULTS

In total, 97 patients were included, with four patients suffering from SSIs. Patients with SSIs had a significantly increased WBC count and CRP levels on the third postoperative day. Infection was diagnosed after rehospitalization, 12 ± 4 weeks after initial surgery. Furthermore, a large bony destruction through trauma coincides with a rise of WBC count with no influence on CRP level.

CONCLUSION

We highly recommend a laboratory analysis with WBC count and CRP on the third day after ORIF. Patients with a CRP level above 100 mg/l should be closely watched, even if laboratory parameters few days later are adequate-since a one-time increase above this landmark might be a hint regarding the development of a SSI.

Time Trends in Characteristics of Patients Undergoing Primary Total Hip and Knee Arthroplasty in California, 2007-2010

BACKGROUND

As the number of total hip and knee arthroplasty cases increases, it is important to understand the burden of factors that impact patient outcomes of these procedures. This article examined the time trends in key demographics, clinical characteristics, comorbidity burden (Deyo-Charlson Comorbidity Index [CCI]), and presence of depression in patients undergoing primary total hip arthroplasty and total knee arthroplasty using population-based, all-payer inpatient database, California Healthcare Cost and Utilization Project, from 2007 to 2010.

METHODS

Chi-square tests and analysis of variance were used. Multivariate logistic regression analyses were also performed to compare the prevalence of depression in 2007 to later years.

RESULTS

In the primary total hip arthroplasty cohort, the prevalence of depression significantly increased by 20%, mean age decreased by 0.4 years, mean length of stay (LOS) decreased by 0.5 days, and having a CCI score of ≥3 increased by 30% (P value < .001 for all) over the study period. Similarly, in the primary total knee arthroplasty cohort, the prevalence of depression increased by 23%, the mean age decreased by 0.4 years, mean LOS decreased by 0.4 days, and the prevalence of CCI score of ≥3 increased by 35% (P value < .001 for all).

CONCLUSION

Despite the younger age of the joint arthroplasty population over time, we found increased prevalence of depression and comorbidity scores but shorter LOS. Further study is needed to determine the impact of the changing demographics of the total joint population and the best strategies to optimize their outcome with these procedures.

Decreased rate of surgical site infection after spinal surgery with instrumentation using bundled approach including surveillance and intrawound vancomycin application

Surgical site infections (SSIs) increase the risk of mortality, postsurgery, extend hospital stay, and increase the costs of healthcare. Our aim in this study was to evaluate the effectiveness of a multidisciplinary, evidence-based, surveillance program combined with intrawound application of vancomycin in lowering the incidence rate of SSI after spinal surgery with instrumentation.We conducted a retrospective analysis of 637 patients who underwent spinal fusion with instrumentation in our institution at 3 different time periods: prior to our surveillance program (control group), surveillance only (surveillance group 1), and surveillance combined with intrawound vancomycin application (surveillance group 2). The following covariates were considered in the evaluation of between-group differences in SSI rate: sex, age, surgical site, National Nosocomial Infection Surveillance (NNIS) risk index, American Society of Anesthesiologists (ASA) physical status classification, and other health comorbidities. The causative organism in cases of SSI was confirmed in all cases.The rate of SSI was significantly lower in the surveillance group 2 (1.4%) than in the control group (4.6%; P = .04). On multivariate logistic regression analysis, steroid use (adjusted odd's ratio (OR), 6.06; 95% confidence interval (CI), 1.45-23.6) and operative time (adjusted OR.1.01; 95% CI, 1.00-1.01) were identified as independent risk factors of SSI. Staphylococcus species and Propionibacterium acnes were the principal causative organisms.A bundled approach that includes surveillance and intrawound application of vancomycin is an effective strategy to lower the risk of SSI after spinal fusion with instrumentation. The use of steroid and longer operative time are risk factors of SSI.Our findings support the implementation of a program of surveillance, combined with intrawound vancomycin application, to reduce the incidence rate of SSIs in spinal surgery.

Patient and surgical factors affecting procedure duration and revision risk due to deep infection in primary total knee arthroplasty

BACKGROUND

The aim of this study was to assess which patient and procedure factors affected both the risk of infection as well as procedure duration. Additionally, to assess if procedure duration affected the revision risk due to deep infection in total knee arthroplasty (TKA) patients and in a subgroup of low-risk patients.

METHODS

28,262 primary TKA with 311 revisions due to deep infection were included from the Norwegian Arthroplasty Register (NAR) and analysed from primary surgery from 2005 until 31st December 2015 with a 1 and 4 year follow up. The risk of revision due to deep infection was calculated in a multivariable Cox regression model including patient and procedure related risk factors, assessing Hazard Ratio (HR) with 95% confidence interval (CI).

RESULTS

Multivariate analysis showed statistically significant associations with revision due to deep infection and increased procedure duration for male patients, ASA3+ (American Society of Anesthesiologists) and perioperative complications. Procedure duration ≥110 min (75 percentile) had a higher risk of deep infection compared to duration <75 min (25 percentile), in the unadjusted analysis (HR = 1.8, 95% CI 1.3-2.5, p = 0.001) and in the adjusted analysis (HR = 1.5, 95% CI 1.0-2.1, p = 0.03). For low-risk patients, procedure duration did not increase the risk of infection.

CONCLUSION

Male patients, ASA 3+ patients and perioperative complications were risk factors both for longer procedure duration and for deep infection revisions. Patients with a high degree of comorbidity, defined as ASA3+, are at risk of infection with longer procedure durations. The occurrence of perioperative complications potentially leading to a more complex and lengthy procedure was associated with a higher risk of infection. Long procedure duration in itself seems to have minor impact on infection since we found no association in the low-risk patient.

Prolonged Operative Duration Increases Risk of Surgical Site Infections: A Systematic Review

Background: The incidence of surgical site infection (SSI) across surgical procedures, specialties, and conditions is reported to vary from 0.1% to 50%. Operative duration is often cited as an independent and potentially modifiable risk factor for SSI. The objective of this systematic review was to provide an in-depth understanding of the relation between operating time and SSI.

Patients and Methods: This review included 81 prospective and retrospective studies. Along with study design, likelihood of SSI, mean operative times, time thresholds, effect measures, confidence intervals, and p values were extracted. Three meta-analyses were conducted, whereby odds ratios were pooled by hourly operative time thresholds, increments of increasing operative time, and surgical specialty.

Results: Pooled analyses demonstrated that the association between extended operative time and SSI typically remained statistically significant, with close to twice the likelihood of SSI observed across various time thresholds. The likelihood of SSI increased with increasing time increments; for example, a 13%, 17%, and 37% increased likelihood for every 15 min, 30 min, and 60 min of surgery, respectively. On average, across various procedures, the mean operative time was approximately 30 min longer in patients with SSIs compared with those patients without.

Conclusions: Prolonged operative time can increase the risk of SSI. Given the importance of SSIs on patient outcomes and health care economics, hospitals should focus efforts to reduce operative time.

Effect of Medicare’s Nonpayment Policy on Surgical Site Infections Following Orthopedic Procedures

OBJECTIVE

Orthopedic procedures are an important focus in efforts to reduce surgical site infections (SSIs). In 2008, the Centers for Medicare and Medicaid (CMS) stopped reimbursements for additional charges associated with serious hospital-acquired conditions, including SSI following certain orthopedic procedures. We aimed to evaluate the CMS policy’s effect on rates of targeted orthopedic SSIs among the Medicare population.

DESIGN

We examined SSI rates following orthopedic procedures among the Medicare population before and after policy implementation compared to a similarly aged control group. Using the Nationwide Inpatient Sample database for 2000–2013, we estimated rate ratios (RRs) of orthopedic SSIs among Medicare and non-Medicare patients using a difference-in-differences approach.

RESULTS

Following policy implementation, SSIs significantly decreased among both the Medicare and non-Medicare populations (RR, 0.7; 95% confidence interval [CI], 0.6–0.8) and RR, 0.8l; 95% CI, 0.7–0.9), respectively. However, the estimated decrease among the Medicare population was not significantly greater than the decrease among the control population (RR, 0.9; 95% CI, 0.8–1.1).

CONCLUSIONS

While SSI rates decreased significantly following the implementation of the CMS nonpayment policy, this trend was not associated with policy intervention but rather larger secular trends that likely contributed to decreasing SSI rates over time.

Infect Control Hosp Epidemiol 2017;38:817–822

Impact of nosocomial infections surveillance on nosocomial infection rates: A systematic review

BACKGROUND

According to previously studies, nosocomial infections (NIs) surveillance could effectively reduce infection rates. As NIs surveillance systems have been implemented in some hospitals for several years, their impact on NIs need to be explored. Therefore, the purpose of this review is to evaluate the tendency of NI rates during the surveillance period and the impact of surveillance on NI rates.

METHODS

A systematic literature search of the PubMed database to identify papers that evaluated effect of surveillance on NIs, all kinds of NIs occurred during hospitalization or discharged were included. Exclude articles investigated the surveillance combined with other infection control measures.

RESULTS

Twenty-five articles were included. NI rates had different levels of reduction during surveillance period, the reduction were not limited by state, department, surveillance system, and NI type. Continuous surveillance had a positive impact on NI, OR/RR were ranged from 0.43 to 0.95.

CONCLUSION

Participation in NI surveillance is associated with reducing infection rates, though RCTs need to further prove the effective role of surveillance. Hospitals may consider to perform NIs surveillance systems according to its own conditions.

Five-year decreased incidence of surgical site infections following gastrectomy and prosthetic joint replacement surgery through active surveillance by the Korean Nosocomial Infection Surveillance System

BACKGROUND

Surveillance of healthcare-associated infection has been associated with a reduction in surgical site infection (SSI).

AIM

To evaluate the Korean Nosocomial Infection Surveillance System (KONIS) in order to assess its effects on SSI since it was introduced.

METHODS

SSI data after gastrectomy, total hip arthroplasty (THA), and total knee arthroplasty (TKA) between 2008 and 2012 were analysed. The pooled incidence of SSI was calculated for each year; the same analyses were also conducted from hospitals that had participated in KONIS for at least three consecutive years. Standardized SSI rates for each year were calculated by adjusting for SSI risk factors. SSI trends were analysed using the Cochran-Armitage test.

FINDINGS

The SSI rate following gastrectomy was 3.12% (522/16,918). There was a significant trend of decreased crude SSI rates over five years. This trend was also evident in analysis of hospitals that had participated for more than three years. The SSI rate for THA was 2.05% (157/7656), which decreased significantly from 2008 to 2012. The risk factors for SSI after THA included the National Nosocomial Infections Surveillance risk index, trauma, reoperation, and age (60-69 years). The SSI rate for TKA was 1.90% (152/7648), which also decreased significantly during a period of five years. However, the risk-adjusted analysis of SSI did not show a significant decrease for all surgical procedures.

CONCLUSION

The SSI incidence of gastrectomy and prosthetic joint replacement declined over five years as a result of active surveillance by KONIS.

Surgical site infection risk factors and risk stratification

Preoperative identification of the risk factors for surgical site infection and patient risk stratification are essential for deciding whether surgery is appropriate, educating patients on their individual risk of complications, and managing postoperative expectations. Early identification of these factors is also necessary to help guide both patient medical optimization and perioperative care planning. Several resources are currently available to track and analyze healthcare-associated infections, including the Centers for Disease Control and Prevention's National Healthcare Safety Network. In addition, the Centers for Disease Control and Prevention and the American Academy of Orthopaedic Surgeons are exploring collaborative opportunities for the codevelopment of a hip and/or knee arthroplasty national quality measure for periprosthetic joint infection.

Diminishing Surgical Site Infections in Australia: Time Trends in Infection Rates, Pathogens and Antimicrobial Resistance Using a Comprehensive Victorian Surveillance Program, 2002–2013

OBJECTIVE

To evaluate time trends in surgical site infection (SSI) rates and SSI pathogens in Australia.

DESIGN

Prospective multicenter observational cohort study.

SETTING

A group of 81 Australian healthcare facilities participating in the Victorian Healthcare Associated Infection Surveillance System (VICNISS).

PATIENTS

All patients underwent surgeries performed between October 1, 2002, and June 30, 2013. National Healthcare Safety Network SSI surveillance methods were employed by the infection prevention staff at the participating hospitals.

INTERVENTION

Procedure-specific risk-adjusted SSI rates were calculated. Pathogen-specific and antimicrobial-resistant (AMR) infections were modeled using multilevel mixed-effects Poisson regression.

RESULTS

A total of 183,625 procedures were monitored, and 5,123 SSIs were reported. Each year of observation was associated with 11% risk reduction for superficial SSI (risk ratio [RR], 0.89; 95% confidence interval [CI], 0.88–0.90), 9% risk reduction for deep SSI (RR, 0.91; 95% CI, 0.90–0.93), and 5% risk reduction for organ/space SSI (RR, 0.95; 95% CI, 0.93–0.97). Overall, 3,318 microbiologically confirmed SSIs were reported. Of these SSIs, 1,174 (35.4%) were associated with orthopedic surgery, 827 (24.9%) with coronary artery bypass surgery, 490 (14.8%) with Caesarean sections, and 414 (12.5%) with colorectal procedures. Staphylococcus aureus was the most frequently identified pathogen, and a statistically significant increase in infections due to ceftriaxone-resistant Escherichia coli was observed (RR, 1.37; 95% CI, 1.10–1.70).

CONCLUSIONS

Standardized SSI surveillance methods have been implemented in Victoria, Australia. Over an 11-year period, diminishing rates of SSIs have been observed, although AMR infections increased significantly. Our findings facilitate the refinement of recommended surgical antibiotic prophylaxis regimens and highlight the need for a more expansive national surveillance strategy to identify changes in epidemiology.

Infect Control Hosp Epidemiol 2015;00(0): 1–8

Are outcomes after total knee arthroplasty worsening over time? A time-trends study of activity limitation and pain outcomes

Background

To examine whether function and pain outcomes of patients undergoing primary total knee arthroplasty (TKA) are changing over time.

Methods

The Mayo Clinic Total Joint Registry provided data for time-trends in preoperative and 2-year post-operative activity limitation and pain in primary TKA patients from 1993-2005. We used chi-square test and analysis for variance, as appropriate. Multivariable-adjusted analyses were done using logistic regression.

Results

In a cohort of 7,229 patients who underwent primary TKA during 1993-2005, mean age was 68.4 years (standard deviation (SD), 9.8), mean BMI was 31.1 (SD, 6.0) and 55% were women. Crude estimates showed that preoperative moderate-severe overall limitation were seen in 7.3% fewer patients and preoperative moderate-severe pain in 2.7% more patients in 2002-05, compared to 1992-95 (p < 0.001 for both). At 2-years, crude estimates indicated that compared to 1992-95, moderate-severe post-TKA overall limitation was seen in 4.7% more patients and moderate-severe post-TKA pain in 3.6% more patients in 2002-05, both statistically significant (p ≤ 0.018) and clinically meaningful. In multivariable-adjusted analyses that adjusted for age, sex, anxiety, depression, Deyo-Charlson index, body mass index and preoperative pain/limitation, patients had worse outcomes 2-year post-TKA in 2002-2005 compared to 1993-95 with an odds ratio (95% confidence interval (CI); p-value) of 1.34 (95% CI: 1.02, 1.76, p = 0.037) for moderate-severe activity limitation and 1.79 (95% CI: 1.17, 2.75, p = 0.007) for moderate-severe pain.

Conclusion

Patient-reported function and pain outcomes after primary TKA have worsened over the study period 1993-95 to 2002-05. This time-trend is independent of changes in preoperative pain/limitation and certain patient characteristics.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-440) contains supplementary material, which is available to authorized users.

Surgical Site Infections in Orthopaedic Surgery Demonstrate Clones Similar to Those in Orthopaedic Staphylococcus aureus Nasal Carriers

BACKGROUND

Staphylococcus aureus is the main microbial pathogen in orthopaedic infections, and it adds considerable extra costs to the national health-care system each year. Nasal carriers of Staphylococcus aureus have an increased risk of invasive disease, including surgical site infection. The purpose of the present study was to investigate whether the Staphylococcus aureus carrier clones found in patients undergoing elective orthopaedic surgery were the same as the clones found in isolates from orthopaedic patients with Staphylococcus aureus surgical site infections.

METHODS

Patients admitted for elective orthopaedic surgery underwent nasal cultures for Staphylococcus aureus. Further, orthopaedic patients with a deep surgical site infection caused by Staphylococcus aureus were characterized using the same genotyping methods: multilocus sequence typing and staphylococcal protein A typing.

RESULTS

Multilocus sequence typing revealed a large number of genotypes in the two populations. However, 85% of nasal carriers and 90% of surgical site infection isolates could be classified into the same four multilocus sequence typing clonal complexes. The risk of Staphylococcus aureus surgical site infection in nasal carriers compared with non-carriers was 5.8 times higher (95% confidence interval, 1.5 to 23.1 times). Of the nasal carriers, 6.3% (95% confidence interval, 1.7% to 10.9% [seven of 111 patients]) developed a deep Staphylococcus aureus surgical site infection, and all but one patient had identical genotypes in the nasal and surgical site infection isolates.

CONCLUSIONS

Staphylococcus aureus isolates from nasal carriers and patients with surgical site infection clustered into the same few multilocus sequence typing clonal complexes. This finding confirms the existence of some commonly occurring Staphylococcus aureus clones in different population groups within a geographically restricted area. The almost complete individual concordance between Staphylococcus aureus genotypes in carriers who developed a deep surgical site infection strongly supports transmission from the nose, skin surfaces, and other endogenous body regions as a possible route.

CLINICAL RELEVANCE

Surgical site infections might be more frequently caused by endogenous transmission than was previously assumed. Perioperative preventive efforts must focus more on this route to further decrease the risk of postoperative orthopaedic infections.

Time trends in the characteristics of patients undergoing primary total knee arthroplasty

OBJECTIVE

To study the time trends in sociodemographic and clinical characteristics of patients undergoing primary total knee arthroplasty (TKA).

METHODS

We used the Mayo Clinic Total Joint Registry to examine the time trends in patient demographics (body mass index [BMI] and age), underlying diagnosis, medical (Deyo-Charlson Index) and psychological comorbidity (anxiety and depression), and examination findings of primary TKA patients from 1993-2005. We used the chi-square test and analysis of variance.

RESULTS

In total, 7,229 patients constituted the primary TKA cohort; 55% were women. The mean age decreased by 1.3 years (69.3 to 68.0 years), mean BMI increased by 1.7 kg/m(2) (30.1 to 31.8 kg/m(2) ), and mean Deyo-Charlson Index increased by 36% (1.1 to 1.5) over the 13-year study period (P ≤ 0.001 for all). Compared with 1993-1995, significantly more patients (by 2-3 times) in 2002-2005 had a BMI ≥40 kg/m(2) (4.8% versus 10.6%), age <50 years (2.9% versus 5.2%), Deyo-Charlson Index of ≥3 (12% versus 22.3%), depression (4.1% versus 14.8%), and anxiety (4.1% versus 8.9%), and significantly fewer patients had an underlying diagnosis of rheumatoid/inflammatory arthritis (6.4% versus 1.5%; P < 0.001 for all). Compared with 1993-1995, significant reductions were noted in 2002-2005 for the physical examination findings of anteroposterior knee instability, mediolateral knee instability, moderate to severe knee synovitis, severe limp, fair or poor muscle strength, and absent peripheral pulses (P ≤ 0.001 for all).

CONCLUSION

In this large US total joint registry study, we found significant time trends in patient characteristics, diagnosis, comorbidity, and knee/extremity examination findings in primary TKA patients over 13 years. These secular trends should be taken into account when comparing outcomes over time and in policy-making decisions.

Minimally invasive versus open sacroiliac joint fusion: are they similarly safe and effective?

BACKGROUND

The sacroiliac joint has been implicated as a source of chronic low back pain in 15% to 30% of patients. When nonsurgical approaches fail, sacroiliac joint fusion may be recommended. Advances in intraoperative image guidance have assisted minimally invasive surgical (MIS) techniques using ingrowth-coated fusion rods; however, how these techniques perform relative to open anterior fusion of the sacroiliac joint using plates and screws is not known.

QUESTIONS/PURPOSES

We compared estimated blood loss (EBL), surgical time, length of hospital stay (LOS), and Oswestry Disability Index (ODI) between patients undergoing MIS and open sacroiliac joint fusion.

METHODS

We retrospectively studied 63 patients (open: 36; MIS: 27) who underwent sacroiliac joint fusion with minimum 1-year followup at our institution from 2006 to 2011. Of those, 10 in the open group had incomplete records. All patients had sacroiliac joint dysfunction confirmed by image-guided intraarticular anesthetic sacroiliac joint injection and had failed nonoperative treatment. Patients were matched via propensity score, adjusting for age, sex, BMI, history of spine fusion, and preoperative ODI scores, leaving 22 in each group. Nine patients were not matched. We reviewed patient medical records to obtain EBL, length of surgery, LOS, and pre- and postoperative ODI scores. Mean followup was 13 months (range, 11-33 months) in the open group and 15 months (range, 12-26 months) in the MIS group.

RESULTS

Patients in the open group had a higher mean EBL (681 mL versus 41 mL, p < 0.001). Mean surgical time and LOS were shorter in the MIS group than in the open group (68 minutes versus 128 minutes and 3.3 days versus 2 days, p < 0.001 for both). With the numbers available, mean postoperative ODI scores were not different between groups (47% versus 54%, p = 0.272).

CONCLUSIONS

EBL, surgery time, and LOS favored the MIS sacroiliac fusion group. With the numbers available, ODI scores were similar between groups, though the study size was relatively small and it is possible that the study was underpowered on this end point. Because the implants used for these procedures make assessment of fusion challenging with available imaging techniques, we do not know how many patients' sacroiliac joints successfully fused, so longer followup and critical evaluation of outcomes scores over time are called for.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Open versus minimally invasive sacroiliac joint fusion: a multi-center comparison of perioperative measures and clinical outcomes

Background

Sacroiliac (SI) joint pain is an under diagnosed source of low back pain due in part to lack of visible pathology on radiographs and symptoms mimicking other back-related disorders. Open SI joint fusion has been performed since the 1920s. This technique has fallen out of favor with the introduction of minimally invasive options. To date there has been no direct comparison between open and MIS SI joint fusion.

Methods

We conducted a multi-center, retrospective comparative cohort study of patients who underwent SI joint fusion using either an open surgical (OS) technique using a combination of screws and cages or a minimally invasive surgical (MIS) technique with a series of titanium plasma spray (TPS) coated triangular implants. Operative measures including surgical operating time, length of hospitalization and estimated blood loss (EBL) were collected along with demographics and medical history, surgical complications, and 12- and 24-month pain scores. Improvements in pain were compared after matching for age and gender and controlling for a history of lumbar spine fusion using repeated measures analysis of variance.

Results

Data were available for 263 patients treated by 7 surgeons; 149 patients treated with OS and 114 treated with MIS SI joint fusion. Compared to OS patients, MIS patients were on average 10 years older (mean age 57 vs. 46) and 69% of all patients were female. MIS operative measures of EBL, operating time and length of hospitalization were significantly lower than open surgery (p < 0.001). Pain relief, measured as change from baseline to 12 months in VAS pain rating, was 3.5 points lower in the MIS vs. OS group (-6.2 vs. -2.7 points, p < 0.001). When matched for age, gender and a history of prior lumbar spinal fusion, postoperative pain scores were on average 3.0 points (95% CI 2.1 – 4.0) lower in MIS vs. OS (rANOVA p < 0.001).

Conclusions

In this multi-center comparative study, patients who underwent either OS or MIS SI joint fusion showed postoperative improvements in pain score. Compared to OS patients, patients who underwent MIS SI joint fusion had significantly greater pain relief and more favorable perioperative surgical measures.

Treatment and prevention of postoperative complications in hip fracture patients: infections and delirium

The course of older patients with hip fractures is often complicated by infections and delirium. Accurate care and high suspicion for these complications are essential, since these conditions are associated with an increase in mortality, length of hospital stay and nursing home placement, poorer mobility, and functional decline. Because of immunosenescence and higher infection rates, older patients need specific care, immediate diagnosis, and treatment of infections. Numerous guidelines of various medical societies outline the management of nosocomial infections, but there is a need of an individualized treatment plan because of comorbidities and polypharmacy. Hygiene measures have first priority to reduce the rate of infections. Treatment of geriatric syndromes like malnutrition, exsiccosis, gait disorders, falls, delirium, urine incontinence, and organ insufficiency are as important as immunization against pneumococci and influenza. Advanced age, cognitive impairment, hearing loss, peripheral vascular disease, prior delirium episodes, sight disorders, and polypharmacy are established risk factors for delirium; thus, older people with several chronic diseases are prone to delirium. A multifactorial approach, comprising standardized screening, oxygen support, intravenous fluid administration and augmented nutrition, monitoring of vital signs, pain treatment, optimized medication, and modification in perioperative management, significantly reduces delirium incidence during hospitalization for hip fracture. An interdisciplinary approach between surgeons and geriatricians may warrant optimized satisfaction of patients' needs.