Burden of Surgical Site Infections Associated with Arthroplasty and the Contribution of Staphylococcus aureus

Getting the drop on Staphylococcus aureus: Semiquantitative Staphylococcus aureus nasal colony reduction in orthopedic surgery reduces surgical site infection

BACKGROUND

Surgical site infection (SSI) is a frequent health care-associated infection. We aimed to reduce SSI risk after joint arthroplasty and spine surgery by reducing Staphylococcus aureus colonization burden with presurgery intranasal povidone-iodine (PVP-I) application in conjunction with skin antisepsis ("the intervention").

METHODS

Retrospective case-control study; postintervention cohort versus a historical cohort. Adults who underwent joint arthroplasty or spine surgery during February 2018 through October 2021 ("post-intervention cohort") included. In the analysis cases any patient who underwent surgery and developed SSI within 90 days postsurgery, controls had no SSI. Postintervention cohort data were compared with a similar retrospective 2016 to 2017 patient cohort that did not use intranasal PVP-I.

RESULTS

The postintervention cohort comprised 688 consecutive patients aged 65y/o, 48.8% male, 28 cases, and 660 controls. Relatively more cases than controls had diabetes mellitus (P = .019). There was a 39.6% eradication rate of S aureus nasal colonization post intranasal PVP-I (P < .0001). SSI rate was higher in patients positive versus those negative for S aureus on a 24-hour postsurgery nasal culture (P < .0001). The deep SSI rate per 100 operations postintervention versus the historical cohort decreased for all surgical procedures.

CONCLUSIONS

Semiquantitative S aureus nasal colony reduction using intranasal PVP-I is effective for decreasing SSI rate in joint arthroplasty and spine surgery. In patients with presurgery S aureus nasal colonization additional intranasal PVP-I postsurgery application should be considered.

Barbed sutures and skin adhesives improve wound closure in hip and knee arthroplasty

PURPOSE

This study aimed to formulate evidence-based recommendations for optimising wound management in hip and knee arthroplasty by exploring alternative methods such as barbed sutures and skin adhesives.

METHODS

A Delphi panel, comprising seven orthopaedic surgeons, one musculoskeletal infectious disease specialist, and one health economics expert, was convened to evaluate the use of barbed sutures and skin adhesives for wound closure in hip and knee arthroplasty. Two systematic reviews informed the development of questionnaires, with panelists ranking their agreement on statements using a 5-point Likert scale. Consensus was achieved if ≥75% agreement. Unresolved statements were revisited in a second round.

RESULTS

Consensus was reached on 11 statements, providing evidence-based recommendations. The expert panel advocates for a multilayer watertight technique using barbed sutures to prevent surgical site infections (SSI), reduce complications, shorten surgical times, optimise resources and improve cosmetic appearance. For skin closure, the panel recommends topical adhesives to decrease wound dehiscence, enhance cosmetic appearance, promote patient compliance, prevent SSIs, and optimise resources.

CONCLUSION

The Delphi consensus by Italian total joint arthroplasty experts underscores the pivotal role of barbed sutures and skin adhesives in optimising outcomes. While guiding clinical decision-making, these recommendations are not prescriptive and should be adapted to local practices. The study encourages further research to enhance current evidence.

LEVEL OF EVIDENCE

Level III.

Incidence, associated disease burden and healthcare utilization due to Staphylococcus aureus prosthetic joint infection in European hospitals: the COMBACTE-NET ARTHR-IS multi-centre study

BACKGROUND

The aim of this study was to estimate the incidence, associated disease burden and healthcare utilization due to Staphylococcus aureus prosthetic joint infections (SA-PJI) after primary hip and knee arthroplasty in European centres.

METHODS

This study was conducted in patients who underwent primary hip and knee arthroplasty in 19 European hospitals between 2014 and 2016. The global incidence of PJI and SA-PJI was calculated. The associated disease burden was measured indirectly as infection-related mortality plus loss of function. For healthcare utilization, number and duration of hospitalizations, number and type of surgical procedures, duration of antibiotic treatments, and number of outpatient visits were collected. Subgroup and regression analyses were used to evaluate the impact of SA-PJI on healthcare utilization, controlling for confounding variables.

RESULTS

The incidence of PJI caused by any micro-organism was 1.41%, and 0.40% for SA-PJI. Among SA-PJI, 20.7% were due to MRSA with substantial regional differences, and were more frequent in partial hip arthroplasty (PHA). Related deaths and loss of function occurred in 7.0% and 10.2% of SA-PJI cases, respectively, and were higher in patients with PHA. Compared with patients without PJI, patients with SA-PJI had a mean of 1.4 more readmissions, 25.1 more days of hospitalization, underwent 1.8 more surgical procedures, and had 5.4 more outpatient visits, controlling for confounding variables. Healthcare utilization was higher in patients who failed surgical treatment of SA-PJI.

CONCLUSIONS

This study confirmed that the SA-PJI burden is high, especially in PHA, and provided a solid basis for planning interventions to prevent SA-PJI.

Prophylactic Antibiotics in Hip Fracture Surgery: A Randomized Prospective Study

Introduction Hip fracture surgeries constitute a large portion of orthopedic surgeries, and infective complications are one of the most severe and devastating sequels following fixations or replacements. Preoperative antibiotic prophylaxis is an important means to control SSI. Thus, we set out to assess the impact of a single dose versus three doses of antibiotics on surgical site infections in patients undergoing hip surgery. Materials and methods A randomized controlled trial was conducted at the Department of Orthopaedics, The Indus Hospital, Karachi, Pakistan. All patients admitted for hip fracture surgery who met the inclusion criteria were enrolled and divided into two groups. One group (Group A) was given a single dose of antibiotics preoperatively, and the other (Group B) was given three doses, one preoperatively and two postoperatively. Patients were assessed for wound condition and signs of infection. Data were entered and analyzed using SPSS version 21.0. The chi-square test was applied to assess the significant association between both the groups and SSI. A significant statistical association was noted when the P value was found to be <0.05. Results The study included 62 patients, with the majority of them being females (n=33; 53.2%). The mean age of the patients was 60.5±15.1 years. Only three (4.8%) patients developed SSI. No statistically significant association was detected between surgical site infections and the two antibiotic regimens being administered after controlling for the confounders. Conclusion There was no statistical relationship between surgical site infections with a single dose versus three doses of antibiotics in patients undergoing hip surgery.

Occlusive wound closure prevents prolonged wound discharge-A randomised controlled trial in patients undergoing tumour resection and endoprosthetic reconstruction of the proximal femur because of metastatic bone disease

Prolonged wound discharge is a common postoperative complication of orthopaedic procedures and a risk factor for implant-related infection. Occlusive wound closure methods have previously been suggested to reduce or even prevent this complication. We performed a randomised controlled trial on 70 patients who underwent surgical treatment for metastatic bone disease involving the proximal femur at our centre between January 2017 and August 2018. At conclusion of the tumour resection and endoprosthetic reconstruction procedure, patients were randomised to either occlusive wound closure (n = 35), using the Dermabond Prineo-22 skin closure system, or routine wound closure with conventional skin staples (n = 35). Skin closure with occlusive wound closure resulted in a lesser degree (P < .0001) and shorter duration of postoperative wound discharge (HR 2.89 [95% CI 1.6-5.05], P < .0018). Compared with staples, surgical wounds were already dry after a mean of 3.5 days [95% CI 3.2-3.9] versus 6.1 days [95% CI 4.8-7.3] (P < .0001). Prolonged wound discharge for 7 days or more was observed in 23% of patients (n = 8) in the Staples-group but was entirely absent in the occlusive wound closure group (P < .003). This study provides strong evidence that occlusive wound closure reduces frequency, degree, and duration of wound discharge in a patient population at particularly high risk for this complication.

[Translated article] Results of a preoperative screening and decolonization programme for Staphylococcus aureus in primary hip and knee arthroplasty

INTRODUCTION

Detection and decolonization of Staphylococcus aureus prior to surgery is postulated as an option to reduce the risk of infection in arthroplasties. The aim of this study was to evaluate the effectiveness of a screening programme for S. aureus in total knee arthroplasty (TKA) and total hip arthroplasty (THA), the incidence of infection with respect to a historical cohort, and its economic viability.

MATERIAL AND METHODS

Pre-post intervention study in patients undergoing primary knee and hip prostheses in 2021, a protocol was carried out to detect nasal colonization by S. aureus and eradication if appropriate, with intranasal mupirocin, post-treatment culture with results three weeks between post-treatment culture and surgery. Efficacy measures are evaluated, costs are analyzed and the incidence of infection is compared with respect to a historical series of patients operated on between January and December 2019, performing a descriptive and comparative statistical analysis.

RESULTS

The groups were statistically comparable. Culture was performed in 89%, with 19 (13%) positive patients. Treatment was confirmed in 18, control culture in 14, all decolonized; none suffered infection. One culture-negative patient suffered from Staphylococcus epidermidis infection. In historical cohort: three suffered deep infection by S. epidermidis, Enterobacter cloacae, Staphylococcus aureus. The cost of the programme is €1661.85.

CONCLUSION

The screening programme detected 89% of the patients. The prevalence of infection in the intervention group was lower than in the cohort, with S. epidermidis being the main micro-organism, different from S. aureus described in the literature and in the cohort. We believe that this programme is economically viable, as its costs are low and affordable.

Surgeon and Facility Volumes Are Associated With Social Disparities and Post-Operative Complications After Total Hip Arthroplasty

BACKGROUND

The purpose of this study is to further characterize the volume dependence of facilities and surgeons on morbidity and mortality after total hip arthroplasty (THA).

METHODS

Adults who underwent THA from 2009 to 2014 were identified using International Classification of Diseases, Ninth Revision, Clinical Modification and Procedural codes in the New York Statewide Planning and Research Cooperative System database. Complication rates were compared across surgeon and facility volumes using multivariable Cox proportional hazards regression controlling for factors such as the Social Deprivation Index. Surgeon and facility volumes were compared between the low and high volume using cutoffs established by prior research.

RESULTS

In total, 99,832 patients were included. Low volume facilities had higher rates of readmission, urinary tract infection (UTI), acute renal failure, pneumonia, surgical site infection (SSI), cellulitis, wound complications, deep vein thrombosis (DVT), in-hospital mortality, and revision. Low volume surgeons had higher rates of readmission, UTI, acute renal failure, pneumonia, SSI, acute respiratory failure, pulmonary embolism, cellulitis, wound complications, in-hospital mortality, cardiorespiratory arrest, DVT, and revision. African Americans, Hispanics, and those with federal insurance had increased rates of readmission. Those with ≥1 Charlson comorbidities or from areas of higher social deprivation had increased incidence of treatment by low volume surgeons and facilities.

CONCLUSION

Both low volume facilities and surgeons performing primary THA have higher rates of readmission, UTI, acute renal failure, pneumonia, SSI, cellulitis, wound complications, DVT, in-hospital mortality, and revision. Demographic disparities exist between who is treated at low vs high volume surgeons and facilities placing those groups at higher risks for complications.

Preoperative and perioperative risk factors, and risk score development for prosthetic joint infection due to Staphylococcus aureus: A multinational matched case-control study

OBJECTIVES

We aim to identify the preoperative and perioperative risk factors associated with post-surgical Staphylococcus aureus prosthetic joint infections (PJI), and to develop and validate risk-scoring systems, to allow a better identification of high-risk patients for more efficient targeted interventions.

METHODS

We performed a multicenter matched case-control study of patients who underwent a primary hip and knee arthroplasty from 2014 to 2016. Two multivariable models by logistic regression were performed, one for the preoperative and one for perioperative variables; also, predictive scores were developed and validated in an external cohort.

RESULTS

In total, 130 cases and 386 controls were included. The variables independently associated with S. aureus-PJI in the preoperative period were (adjusted OR; 95% CI): BMI >30 kg/m² (3.0; 1.9-4.8), resident in a long-term care facility (2.8; 1.05-7.5), fracture as reason for arthroplasty (2.7; 1.4-5.03), skin disorders (2.5; 0.9-7.04), previous surgery in the index joint (2.4; 1.3-4.4), male sex (1.9; 1.2-2.9) and ASA score 3-4 (1.8; 1.2-2.9). The AUROC curve was 0.73 (95% CI 0.68-0.78). In perioperative model, the risk factors were the previous ones plus surgical antibiotic prophylaxis administered out of the first 60 minutes before incision (5.9; 2.1-16.2), wound drainage for >72h after arthroplasty (4.5; 1.9-19.4) and use of metal bearing material vs. ceramic (1.9; 1.1-3.3). The AUROC curve was 0.78 (95% CI 0.72-0.83). The predictive scores developed were validated in the external cohort.

CONCLUSIONS

Predictive scores for S. aureus-PJI were developed and validated; this information would be useful for implementation of specific preventive measures.

Surgeon and Facility Volume are Associated With Postoperative Complications After Total Knee Arthroplasty

Background

Surgeon and hospital volumes may affect outcomes of various orthopedic procedures. The purpose of this study is to characterize the volume dependence of both facilities and surgeons on morbidity and mortality after total knee arthroplasty.

Methods

Adults who underwent total knee arthroplasty for osteoarthritis from 2011 to 2015 were identified using International Classification of Diseases-9 Clinical Modification diagnostic and procedural codes in the New York Statewide Planning and Research Cooperative System database. Readmission, in-hospital mortality, and other adverse events were compared across surgeon and facility volumes using multivariable Cox proportional hazards regression, while controlling for patient demographic and clinical factors. Surgeon and facility volumes were compared between the lowest and highest 20%.

Results

Of 113,784 identified patients, 71,827 were treated at a high- or low-volume facility or by low- or high-volume surgeon. Low-volume facilities had higher 1-month, 3-month, and 12-month rates of readmission, urinary tract infection, cardiorespiratory arrest, surgical site infection, and wound complications; higher 3- and 12-month rates of pneumonia, cellulitis, and in-facility mortality; and higher 12-month rates of acute renal failure and revision. Low-volume surgeons had higher 1-, 3-, and 12-month rates of readmission, urinary tract infection, acute renal failure, pneumonia, surgical site infection, deep vein thrombosis, pulmonary embolism, cellulitis, and wound complications; higher 3- and 12-month rates of cardiorespiratory arrest; and higher 12-month rate of in-facility mortality.

Conclusions

These results suggest volume shifting toward higher volume facilities and/or surgeons could improve patient outcomes and have potential cost savings. Furthermore, these results can inform healthcare policy, for example, designating institutions as centers of excellence.

Multilayer Watertight Closure to Address Adverse Events From Primary Total Knee and Hip Arthroplasty: A Systematic Review of Wound Closure Methods by Tissue Layer

Background

Wound closure is a key, and often underrecognized, component of hip and knee arthroplasty. Methods for wound closure are an important consideration to better avoid wound-related adverse events; however, there is a lack of consensus on optimal methods. The objective of the following review was twofold: to characterize the wound closure methods used by layer in the total knee arthroplasty and total hip arthroplasty literature and summarize optimal wound-healing strategies to address the risk of adverse events.

Methods

A systematic literature review was performed to identify total knee arthroplasty and total hip arthroplasty randomized controlled trials and nonrandomized studies reporting wound closure methods by layer and wound-healing adverse events (including superficial, deep, or periprosthetic joint infections, wound dehiscence, or prolonged wound drainage). Studies on revision procedures were excluded. Wound closure methods and adverse events were summarized qualitatively as meta-analyses were not possible because of study heterogeneity.

Results

Forty studies met the inclusion criteria: 22 randomized controlled trials and 18 observational studies. Across studies, 6 categories and 22 unique techniques for closure were identified. Conventional closure methods exhibited large ranges of adverse event rates. Studies of multilayer barbed sutures with topical skin adhesives and polyester mesh or multilayer antimicrobial sutures reported narrow ranges of adverse events rates.

Conclusions

Considerable variability exists for wound closure methods, with a wide range reported in adverse events. Recent technologies and methods for standardized watertight, multilayer closure show promise for avoiding adverse events and unnecessary health-care costs; however, higher quality, comparative studies are required to enable future meta-analyses.

Level of Evidence

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Efficacy of preoperative screening and decolonization for staphylococcus aureus in total joint arthroplasty: A meta-analysis

The purpose of this study is to conduct a meta-analysis to evaluate the efficacy of screening and decolonization protocol for Staphylococcus aureus (SA) in total joint arthroplasty (TJA). We systematically searched the electronic databases of PubMed, Embase and Cochrane databases for relevant literatures from January 2000 to September 2020. The outcomes were colonization rate, total-surgical site infection (SSI) rate, SA-SSI rate and methicillin-resistant Staphylococcus aureus (MRSA)-SSI rate. All calculations and statistical tests were performed using Stata 14.0 software. A total of 12 studies were eligible in this study. Compared with control group, the screening and decolonization group had lower risks in total-SSI (risk ratio (RR) = 0.52; 95% confidence interval (CI): 0.40-0.67), SA-SSI (RR = 0.48; 95% CI: 0.32-0.72) and MRSA-SSI (RR = 0.45; 95% CI: 0.21-0.96). The nasal SA colonization was found to be associated with higher accidences of SSI involving total-SSI (RR = 1.49; 95% CI: 1.02-2.18), SA-SSI (RR = 2.51; 95% CI: 0.97-6.50) and MRSA-SSI (RR = 7.84; 95% CI: 1.67-36.79). The colonization rate of SA was significantly reduced after decolonization. No difference was observed between universal decolonization and screening-based decolonization. In conclusion, colonization of SA is associated with increased risk of SSI in TJA. Screening and decolonization protocol are proven to be effective to reduce colonization of SA and present protective effects against SSI in TJA. Moreover, universal decolonization protocol is non-inferior to screening-based decolonization.

Healthcare resources attributable to methicillin-resistant Staphylococcus aureus orthopedic surgical site infections

The number of orthopedic surgeries is increasing as populations steadily age, but surgical site infection (SSI) rates remain relatively consistent. This study aimed to quantify the healthcare resources attributable to methicillin-resistant Staphylococcus aureus (MRSA) SSIs in orthopedic surgical patients. The analysis was conducted using a national claims database comprising data from almost all Japanese residents. We examined patients who underwent any of the following surgeries between April 2012 and March 2018: amputation (AMP), spinal fusion (FUSN), open reduction of fracture (FX), hip prosthesis (HPRO), knee prosthesis (KPRO), and laminectomy (LAM). Propensity score matching was performed to identify non-SSI control patients, and generalized estimating equations were used to estimate the differences in outcomes between the case and control groups. The numbers of MRSA SSI cases (infection rates) ranged from 64 (0.03%) to 1,152 (2.33%). MRSA SSI-attributable increases in healthcare expenditure ranged from $11,630 ($21,151 vs. $9,521) for LAM to $35,693 ($50,122 vs. $14,429) for FX, and increases in hospital stay ranged from 40.6 days (59.2 vs. 18.6) for LAM to 89.5 days (122.0 vs. 32.5) for FX. In conclusion, MRSA SSIs contribute to substantial increases in healthcare resource utilization, emphasizing the need to implement effective infection prevention measures for orthopedic surgeries.

Local concentrations of gentamicin obtained by microdialysis after a controlled application of a GentaColl sponge in a porcine model

Local treatment with gentamicin may be an important tool in the prevention and treatment of surgical site infections in high-risk procedures and patients. The aim of this study was to evaluate the pharmacokinetic profile of gentamicin in bone and surrounding tissue, released from a controlled application of a GentaColl sponge in a porcine model. In eight female pigs, a GentaColl sponge of 10 × 10 cm (1.3 mg gentamicin/cm² ) was placed in a cancellous bone cavity in the proximal tibia. Microdialysis was used for sampling of gentamicin concentrations over 48 hours from the cavity with the implanted GentaColl sponge, cancellous bone parallel to the cavity over and under the epiphyseal plate, cortical bone, the intramedullary canal, subcutaneous tissue, and the joint cavity of the knee. Venous blood samples were obtained as reference. The main finding was a mean peak drug concentration (95% CI) of gentamicin in the cancellous bone cavity containing the implanted GentaColl sponge of 11 315 (9049-13 581) μg/mL, persisting above 1000 μg/mL until approximately 40 hours after application. Moreover, the concentrations were low (<1 μg/mL) in the surrounding tissues as well as in plasma. The mean peak gentamicin concentration from the cancellous bone cavity after a controlled application of a GentaColl sponge was high and may be adequate for the prevention of biofilm formation. However, high MIC strains and uncontrolled application of the GentaColl sponge may jeopardize this conclusion.

Burden of Staphylococcus aureus infections after orthopedic surgery in Germany

BACKGROUND

This study assessed incidence, risk factors, and outcomes of Staphylococcus aureus infections (SAI) following endoprosthetic hip or knee, or spine surgeries.

METHODS

Adult patients with at least one of the selected surgeries from 2012 to 2015 captured in a German sickness fund database were included. SAI were identified using S. aureus-specific ICD-10 codes. Patients with certain prior surgeries and infections were excluded. Cumulative incidence and incidence density of post-surgical SAI were assessed. Risk factors, mortality, healthcare resource utilization and direct costs were compared between SAI and non-SAI groups using multivariable analyses over the 1 year follow-up.

RESULTS

Overall, 74,327 patients who underwent a knee (28.6%), hip (39.6%), or spine surgery (31.8%) were included. The majority were female (61.58%), with a mean age of 69.59 years and a mean Charlson Comorbidity Index (CCI) of 2.3. Overall, 1.92% of observed patients (20.20 SAI per 1000 person-years (PY)) experienced a SAI within 1 year of index hospitalization. Knee surgeries were associated with lower SAI risk compared with hip surgeries (Hazard Ratio (HR) = 0.8; p = 0.024), whereas spine surgeries did not differ significantly from hip surgeries. Compared with non-SAI group, the SAI group had on average 4.4 times the number of hospitalizations (3.1 vs. 0.7) and 7.7 times the number of hospital days (53.5 vs. 6.9) excluding the index hospitalization (p < 0.001). One year post-orthopedic mortality was 22.38% in the SAI and 5.31% in the non-SAI group (p < 0.001). The total medical costs were significantly higher in the SAI group compared to non-SAI group (42,834€ vs. 13,781€; p < 0.001). Adjusting for confounders, the SAI group had nearly 2 times the all-cause direct healthcare costs (exp(b) = 1.9; p < 0.001); and 1.72 times higher risk of death (HR = 1.72; p < 0.001).

CONCLUSIONS

SAI risk after orthopedic surgeries persists and is associated with significant economic burden and risk of mortality. Hence, risk reduction and prevention methods are of utmost importance.

Effect of hospital volume on outcomes of total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

A shift in the healthcare system towards the centralization of common yet costly surgeries, such as total hip arthroplasty (THA), to high-volume centers of excellence, is an attempt to control the economic burden while simultaneously enhancing patient outcomes. The "volume-outcome" relationship suggests that hospitals performing more treatment of a given type exhibit better outcomes than hospitals performing fewer. This theory has surfaced as an important factor in determining patient outcomes following THA. We performed a systematic review with meta-analyses to review the available evidence on the impact of hospital volume on outcomes of THA.

MATERIALS AND METHODS

We conducted a review of PubMed (MEDLINE), OVID MEDLINE, Google Scholar, and Cochrane library of studies reporting the impact of hospital volume on THA. The studies were evaluated as per the inclusion and exclusion criteria. A total of 44 studies were included in the review. We accessed pooled data using random-effect meta-analysis.

RESULTS

Results of the meta-analyses show that low-volume hospitals were associated with a higher rate of surgical site infections (1.25 [1.01, 1.55]), longer length of stay (RR, 0.83[0.48-1.18]), increased cost of surgery (3.44, [2.57, 4.30]), 90-day complications (RR, 1.80[1.50-2.17]) and 30-day (RR, 2.33[1.27-4.28]), 90-day (RR, 1.26[1.05-1.51]), and 1-year mortality rates (RR, 2.26[1.32-3.88]) when compared to high-volume hospitals following THA. Except for two prospective studies, all were retrospective observational studies.

CONCLUSIONS

These findings demonstrate superior outcomes following THA in high-volume hospitals. Together with the reduced cost of the surgical procedure, fewer complications may contribute to saving considerable opportunity costs annually. However, a need to define objective volume-thresholds with stronger evidence would be required.

TRIAL REGISTRATION

PROSPERO CRD42019123776.

Highlighting the gaps in quantifying the economic burden of surgical site infections associated with antimicrobial-resistant bacteria

Antibiotics are the pillar of surgery from prophylaxis to treatment; any failure is potentially a leading cause for increased morbidity and mortality. Robust data on the burden of SSI especially those due to antimicrobial resistance (AMR) show variable rates between countries and geographical regions but accurate estimates of the incidence of surgical site infections (SSI) due to AMR and its related global economic impact are yet to be determined. Quantifying the burden of SSI treatment is an incentive to sensitize governments, healthcare systems, and the society to invest in quality improvement and sustainable development. However in the absence of a unified epidemiologically sound infection definition of SSI and a well-designed global surveillance system, the end result is a lack of accurate and reliable data that limits the comparability of estimates between countries and the possibility of tracking changes to inform healthcare professionals about the appropriateness of implemented infection prevention and control strategies. This review aims to highlight the reported gaps in surveillance methods, epidemiologic data, and evidence-based SSI prevention practices and in the methodologies undertaken for the evaluation of the economic burden of SSI associated with AMR bacteria. If efforts to tackle this problem are taken in isolation without a global alliance and data is still lacking generalizability and comparability, we may see the future as a race between the global research efforts for the advancement in surgery and the global alarming reports of the increased incidence of antimicrobial-resistant pathogens threatening to undermine any achievement.

Health state utilities associated with post-surgical Staphylococcus aureus infections

INTRODUCTION

Surgical site infections (SSIs) are among the most common and potentially serious complications after surgery. Staphylococcus aureus is a virulent pathogen frequently identified as a cause of SSI. As vaccines and other infection control measures are developed to reduce SSI risk, cost-utility analyses (CUA) of these interventions are needed to inform resource allocation decisions. A recent systematic review found that available SSI utilities are of "questionable quality." Therefore, the purpose of this study was to estimate the disutility (i.e., utility decrease) associated with SSIs.

METHODS

In time trade-off interviews, general population participants in the UK (London, Edinburgh) valued health states drafted based on literature and clinician interviews. Health states described either joint or spine surgery, with or without an SSI. The utility difference between otherwise identical health states with and without the SSI represented the disutility associated with the SSI.

RESULTS

A total of 201 participants completed interviews (50.2% female; mean age = 46.2 years). Mean (SD) utilities of health states describing joint and spine surgery without infections were 0.79 (0.23) and 0.78 (0.23). Disutilities of SSIs ranged from - 0.03 to - 0.32, depending on severity of the infection and subsequent medical interventions. All differences between corresponding health with and without SSIs were statistically significant (all p < 0.001).

CONCLUSION

The preference-based SSI disutilities derived in this study may be used to represent mild and serious SSIs in CUAs assessing and comparing the value of vaccinations that may reduce the risk of SSIs.

Surgical site infection in elective clean and clean-contaminated surgeries in developing countries

BACKGROUND

Surgical site infection (SSI) is both the most frequently studied healthcare-associated infection and the most common healthcare-associated infection in the developing world. A systematic review and meta-analysis was conducted to evaluate the relative size of this burden and to estimate the prevalence of SSI in clean and clean-contaminated surgeries in a large sample of countries in the developing world.

METHODS

A systematic search of the MEDLINE/PubMed, Scopus, and LILACS databases was conducted to identify studies providing the prevalence of SSI in elective clean and clean-contaminated surgeries in 39 countries or regions around the world. Data of interest were limited to publications from January 2000 to December 2017. Studies with information on the number of cases of SSI and number of total elective clean and clean-contaminated surgeries during the same period were included in this evaluation. Studies lacking clear definition of the total number of exposed patients were excluded.

RESULTS

Based on the combined data from the 99 articles evaluated in this analysis, the overall prevalence of SSI in elective clean and clean-contaminated surgeries was estimated to be 6% (95% confidence interval (CI) 5-7%). This increased to 15% (95% CI 6-27%) when considering only those reports with post-discharge surveillance data. The overall prevalence of SSI in Africa/Middle East, Latin America, Asia, and China was 10% (95% CI 6-15%), 7% (95% CI 5-10%), 4% (95% CI 4-5%), and 4% (95% CI 2-6%), respectively. Significant variability in the data was confirmed by both the funnel plot and the Egger test (p=0.008).

CONCLUSIONS

Although the data are variable, it is clear that the incidence of SSI in the developing world is higher than that in the developed world.

A US hospital budget impact analysis of a skin closure system compared with standard of care in hip and knee arthroplasty

Background

Medicare’s mandatory bundle for hip and knee arthroplasty necessitates provider accountability for quality and cost of care to 90 days, and wound closure may be a key area of consideration. The DERMABOND^® PRINEO^® Skin Closure System (22 cm) combines a topical skin adhesive with a self-adhering mesh without the need for dressing changes or suture or staple removal. This study estimated the budget impact of the Skin Closure System compared to other wound closure methods for hip and knee arthroplasty.

Methods

A 90-day economic model was developed assuming 500 annual hip/knee arthroplasties for a typical US hospital setting. In current practice, wound closure methods for the final skin layer were set to 50% sutures and 50% staples. In future practice, this distribution shifted to 20% sutures, 20% staples, and 60% Skin Closure System. Health care resources included materials (eg, staplers, steri-strips, and traditional/barbed sutures), standard or premium dressings, outpatient visits, and home care visits. An Expert Panel, comprised of three orthopedic physician assistants, two orthopedic surgeons, and a home health representative, was used to inform several model parameters. Other inputs were informed by national data or literature. Unit costs were based on list prices in 2016 US dollars. Uncertainty in the model was explored through one-way sensitivity and alternative scenario analyses.

Results

The analysis predicted that use of Skin Closure System in the future practice could achieve cost savings of $56.70 to $79.62 per patient, when standard or premium wound dressings are used, respectively. This translated to an annual hospital budgetary savings ranging from $28,349 to $39,809 when assuming 500 arthroplasties. Dressing materials and postoperative health care visits were key model drivers.

Conclusions

Use of the Skin Closure System may provide cost savings within hip and knee arthroplasties due to decreases in resource utilization in the postacute care setting.

The development of a staphylococcus aureus four antigen vaccine for use prior to elective orthopedic surgery

Staphylococcus aureus (S. aureus) is a challenging bacterial pathogen which can cause a range of diseases, from mild skin infections, to more serious and invasive disease including deep or organ space surgical site infections, life-threatening bacteremia, and sepsis. S. aureus rapidly develops resistance to antibiotic treatments. Despite current infection control measures, the burden of disease remains high. The most advanced vaccine in clinical development is a 4 antigen S. aureus vaccine (SA4Ag) candidate that is being evaluated in a phase 2b/3 efficacy study in patients undergoing elective spinal fusion surgery (STaphylococcus aureus suRgical Inpatient Vaccine Efficacy [STRIVE]). SA4Ag has been shown in early phase clinical trials to be generally safe and well tolerated, and to induce high levels of bactericidal antibodies in healthy adults. In this review we discuss the design of SA4Ag, as well as the proposed clinical development plan supporting licensure of SA4Ag for the prevention of invasive disease caused by S. aureus in elective orthopedic surgical populations. We also explore the rationale for the generalizability of the results of the STRIVE efficacy study (patients undergoing elective open posterior multilevel instrumented spinal fusion surgery) to a broad elective orthopedic surgery population due to the common pathophysiology of invasive S. aureus disease and commonalties of patient and procedural risk factors for developing postoperative S. aureus surgical site infections.

Qualitative interviews to identify burden of illness, impacts and costs associated with surgical site infections

Aim:

To gather qualitative data from patients on the burden, impacts and costs of surgical site infections (SSI) requiring second surgeries.

Patients & methods:

15 adults with SSIs from spinal (n = 4), knee replacement (n = 3) or hip replacement (n = 8) surgery participated in a focus group or individual interview. Patients completed the PROMIS Physical Functioning (PF) Short Form 10A (PROMIS-PF).

Results:

Patients reported impacts within four primary domains: PF/activity-related; social/emotional; financial/employment; and energy/sleep. The mean PROMIS-PF score was 39.3 (standard deviation = 12.1), over one standard deviation below 50, the US norm.

Conclusion:

SSIs impart a broad and significant impact on patients and their families. These burdens will be important to capture when selecting patient-reported outcome measures for this patient population.

Prophylaxis with nasal decolonization in patients submitted to total knee and hip arthroplasty: systematic review and meta-analysis

Despite the evolution of the total knee and hip arthroplasty surgery, high postoperative complication rates in the short and long term still persist. Infection is one of the most challenging complications; due to its gravity and treatment difficulties, prophylaxis protocols have been created to decrease its incidence. The objective of this study was to evaluate the impact of the prophylaxis protocol for methicillin-resistant Staphylococcus aureus decolonization of the nares in patients previously identified by swab cultures, who were to be submitted to a total joint arthroplasty. A systematic review with meta-analysis was conducted, following the PRISMA-2015 protocol, using the descriptors: "arthroplasty" and "nasal decolonization," or "joint arthroplasty" and "decolonization," or "joint arthroplasty" and "nasal decolonization," for final selection of four observational studies from 79 references identified. This study included a total sample of 10,179 patients, divided in two groups: the control group (4788 patients) and intervention group (5391 patients). It was observed that the intervention group, in which prophylaxis with nasal decolonization was used, 59 (1.09%) of the patients developed a surgical site infection, while in the control group there were 86 cases of surgical site infection (1.79%). This trend repeated itself in all articles, showing no publication biases, forming a homogeneous sample. The use of a prophylaxis protocol for decolonization of methicillin-resistant Staphylococcus aureus, reduced surgical site infection cases by approximately 39%.

Use of surveillance data to calculate the sample size and the statistical power of randomized clinical trials testing Staphylococcus aureus vaccine efficacy in orthopedic surgery

BACKGROUND

Patients undergoing primary total hip arthroplasty (THA) would be a worthy population for anti-staphylococcal vaccines. The objective is to assess sample size for significant vaccine efficacy (VE) in a randomized clinical trial (RCT).

METHODS

Data from a surveillance network of surgical site infection in France between 2008 and 2011 were used. The outcome was S. aureus SSI (SASSI) within 30 days after surgery. Statistical power was estimated by simulations repeated for theoretical VE ranging from 20% to 100% and for sample sizes from 250 to 8000 individuals per arm.

RESULTS

18,688 patients undergoing THA were included; 66 (0.35%) SASSI occurred. For a 1% SASSI rate, the sample size would be at least 1316 patients per arm to detect significant VE of 80% with 80% power.

CONCLUSION

Simulations with real-life data from surveillance of hospital acquired infections allow estimation of power for RCT and sample size to reach the required power.

Readmission due to infection following total hip and total knee procedures: A retrospective study

Policymakers have expanded readmissions penalty programs to include elective arthroplasties, but little is known about the risk factors for readmissions following these procedures. We hypothesized that infections after total hip arthroplasty (THA) and total knee arthroplasty (TKA) lead to excess readmissions and increased costs. This study aims to evaluate the proportion of readmissions due to infections following THA and TKA.Healthcare Cost and Utilization Project-State Inpatient Databases were used for the study. Procedure codes "8151" and "8154" were used to identify inpatient discharges with THA and TKA in Florida (FL) 2009 to 2013, Massachusetts (MA) 2010 to 2012, and California (CA) 2009 to 2011. Readmission was measured by a Centers for Medicare and Medicaid Services (CMS) validated algorithm. Infections were identified by ICD-9-CM codes: 99859, 99666, 6826, 0389, 486, 4821, 00845, 5990, 48242, 04111, 04112, 04119, 0417, 99591, and 99592. Descriptive analysis was performed.In CA, 4.29% of patients were readmitted with 33.02% of the total readmissions for infection. In FL, 4.7% of patients were readmitted with 33.39% of the readmissions for infection. In MA, 3.92% of patients were readmitted with 35.2% of readmissions for infection. Of the total number of readmissions due to infection, methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) together accounted for 14.88% in CA, 13.38% in FL, and 13.11% in MA.The rate of infection is similar across all 3 states and is a leading cause for readmission following THA and TKA. Programs to reduce the likelihood of MRSA or MSSA infection would reduce readmissions due to infection.

Ertapenem Articulating Spacer for the Treatment of Polymicrobial Total Knee Arthroplasty Infection

Introduction. Periprosthetic joint infections (PJIs) are the primary cause of early failure of the total knee arthroplasty (TKA). Polymicrobial TKA infections are often associated with a higher risk of treatment failure. The aim of the study was to assess the efficacy of ertapenem loaded spacers in the treatment of polymicrobial PJI. Methods. There were 18 patients enrolled; nine patients with polymicrobial PJI treated with ertapenem loaded articulating spacers were compared to the group of 9 patients treated with vancomycin or ceftazidime loaded spacers. Results. Successful reimplantation with revision implants was possible in 66.67%. Ertapenem spacers were used in 6 cases in primary two-stage procedure and in 3 cases in secondary spacer exchange. Successful infection eradication was achieved in all cases; final reimplantation with revision knee arthroplasty implants was possible in 6 cases. Conclusion. Ertapenem can be successfully used as antimicrobial addition to the cement spacers in two-stage revision treatment of polymicrobial PJIs. However, this type of spacer may also be useful in the treatment of infections caused by monomicrobial extended spectrum beta-lactamases producing gram-negative bacilli. Further clinical studies are required to evaluate the efficacy and safety of ertapenem spacers in the treatment of polymicrobial and monomicrobial PJIs.