Satisfaction With and Adherence to Off-Label Corticosteroids in Adolescents and Adults With Eosinophilic Esophagitis: Results of a Web-Based Survey in the United States.

GOALS: We assessed satisfaction with and adherence to off-label corticosteroids in patients with eosinophilic esophagitis (EoE) in the United States. BACKGROUND: EoE is a chronic inflammatory disease for which there are currently no US Food and Drug Administration-approved swallowed topical corticosteroids. STUDY: This noninterventional, cross-sectional, web-based survey included caregivers of adolescents (aged 11 to 17 y) and adults (aged 18 years or older) with a self-reported [or caregiver-reported (adolescents)] physician diagnosis of EoE who were receiving corticosteroids. Participants were recruited through 2 nonprofit, patient advocacy groups. The 9-item Treatment Satisfaction Questionnaire for Medication (TSQM-9) was used to assess satisfaction across effectiveness, convenience, and global satisfaction domains (scale: 1 to 100 per domain); higher scores indicated greater satisfaction. The 4-item Morisky Green Levine Medication Adherence Scale (MGL-4) was used to assess adherence; an MGL-4 score of <3 indicated adherence. Participants also reported reasons for nonadherence. RESULTS: Overall, 201 participants (caregivers of adolescents, n=98; adults, n=103) were included in this study. Mean TSQM-9 scores indicated low satisfaction with off-label corticosteroids across all 3 satisfaction domains in adolescents (≤61.1) and adults (≤55.7). Slightly fewer adolescents (37.1%) than adults (40.8%) were considered adherent. Forgetfulness was the most frequently reported reason for nonadherence; some patients chose not to take their medications, owing to poor palatability (adolescents), difficulty taking medications at specific times (adults), or feeling depressed/overwhelmed (adolescents and adults). CONCLUSIONS: Satisfaction with and adherence to off-label corticosteroids were low in this web-based survey of adolescents and adults with EoE in the United States.

Value in Acute Care Surgery, Part 3: Defining Value in Acute Surgical Care - It Depends on the Perspective.

ABSTRACT: The prior articles in this series have focused on measuring cost and quality in acute care surgery. This third article in the series explains the current ways of defining value in acute care surgery, based on different stakeholders in the healthcare system - the patient, the healthcare organization, the payer and society. The heterogenous valuations of the different stakeholders require that the framework for determining high-value care in acute care surgery incorporates all viewpoints.

Managing career transitions in the profession of acute care surgery.

Career shifts are a naturally occurring part of the trauma and acute care surgeon's profession. These transitions may occur at various timepoints throughout a surgeon's career and each has their own specific challenges. Finding a good fit for your first job is critical for ensuring success as an early career surgeon. Equally, understanding how to navigate promotions or a change in job location mid-career can be fraught with uncertainty. As one progresses in their career, knowing when to take on a leadership position is oftentimes difficult as it may mean a change in priorities. Finally, navigating your path towards a fulfilling retirement is a complex discussion that is different for each surgeon. The American Association for the Surgery of Trauma (AAST) convened an expert panel of acute care surgeons in a virtual grand rounds session in August 2023 to address the aforementioned career transitions and highlight strategies for successfully navigating each shift. This was a collaboration between the AAST Associate Member Council (consisting of surgical resident, fellow and junior faculty members), the AAST Military Liaison Committee and the AAST Healthcare Economics Committee. Led by two moderators, the panel consisted of early, mid-career and senior surgeons, and recommendations are summarized below and in figure 1.

Financial toxicity part II: A practical guide to measuring and tracking long-term financial outcomes among acute care surgery patients.

ABSTRACT: Acute care surgery (ACS) patients are frequently faced with significant long-term recovery and financial implications that extend far beyond their hospitalization. While major injury and emergency general surgery (EGS) emergencies are often viewed solely as acute moments of crisis, the impact on patients can be lifelong. Financial outcomes after major injury or emergency surgery have only begun to be understood. The Healthcare Economics Committee from the American Association for the Surgery of Trauma previously published a conceptual overview of financial toxicity in ACS, highlighting the association between financial outcomes and long-term physical recovery. The aims of second-phase financial toxicity review by the Healthcare Economics Committee of the American Association for the Surgery of Trauma are to (1) understand the unique impact of financial toxicity on ACS patients; (2) delineate the current limitations surrounding measurement domains of financial toxicity in ACS; (3) explore the "when, what and how" of optimally capturing financial outcomes in ACS; and (4) delineate next steps for integration of these financial metrics in our long-term patient outcomes. As acute care surgeons, our patients' recovery is often contingent on equal parts physical, emotional, and financial recovery. The ACS community has an opportunity to impact long-term patient outcomes and well-being far beyond clinical recovery.

Estradiol mediates greater germinal center responses to influenza vaccination in female than male mice.

Adult females of reproductive age develop greater antibody responses to inactivated influenza vaccines (IIV) than males. How sex, age, and sex steroid concentrations impact B cells and durability of IIV-induced immunity and protection over 4 months post-vaccination (mpv) was analyzed. Vaccinated adult females had greater germinal center B cell and plasmablast frequencies in lymphoid tissues, higher neutralizing antibody responses 1-4 mpv, and better protection against live H1N1 challenge than adult males. Aged mice, regardless of sex, had reduced B cell frequencies, less durable antibody responses, and inferior protection after challenge than adult mice, which correlated with diminished estradiol among aged females. To confirm that greater IIV-induced immunity was caused by sex hormones, four core genotype (FCG) mice were used, in which the testes-determining gene, Sry, was deleted from chromosome Y (ChrY) and transferred to Chr3 to separate gonadal sex (i.e., ovaries or testes) from sex chromosome complement (i.e., XX or XY complement). Vaccinated, gonadal female FCG mice (XXF and XYF) had greater numbers of B cells, higher antiviral antibody titers, and reduced pulmonary virus titers following live H1N1 challenge than gonadal FCG males (XYM and XXM). To establish that lower estradiol concentrations cause diminished immunity, adult and aged females received either a placebo or estradiol replacement therapy prior to IIV. Estradiol replacement significantly increased IIV-induced antibody responses and reduced morbidity after the H1N1 challenge among aged females. These data highlight that estradiol is a targetable mechanism mediating greater humoral immunity following vaccination among adult females.IMPORTANCEFemales of reproductive ages develop greater antibody responses to influenza vaccines than males. We hypothesized that female-biased immunity and protection against influenza were mediated by estradiol signaling in B cells. Using diverse mouse models ranging from advanced-age mice to transgenic mice that separate sex steroids from sex chromosome complement, those mice with greater concentrations of estradiol consistently had greater numbers of antibody-producing B cells in lymphoid tissue, higher antiviral antibody titers, and greater protection against live influenza virus challenge. Treatment of aged female mice with estradiol enhanced vaccine-induced immunity and protection against disease, suggesting that estradiol signaling in B cells is critical for improved vaccine outcomes in females.

Adaptive, behavioral, and emotional outcomes following postoperative pediatric cerebellar mutism syndrome in survivors treated for medulloblastoma.

OBJECTIVE: Patients who experience postoperative pediatric cerebellar mutism syndrome (CMS) during treatment for medulloblastoma have long-term deficits in neurocognitive functioning; however, the consequences on functional or adaptive outcomes are unknown. The purpose of the present study was to compare adaptive, behavioral, and emotional functioning between survivors with and those without a history of CMS. METHODS: The authors examined outcomes in 45 survivors (15 with CMS and 30 without CMS). Comprehensive neuropsychological evaluations, which included parent-report measures of adaptive, behavioral, and emotional functioning, were completed at a median of 2.90 years following craniospinal irradiation. RESULTS: Adaptive functioning was significantly worse in the CMS group for practical and general adaptive skills compared with the group without CMS. Rates of impairment in practical, conceptual, and general adaptive skills in the CMS group exceeded expected rates in the general population. Despite having lower overall intellectual functioning, working memory, and processing speed, IQ and related cognitive processes were uncorrelated with adaptive outcomes in the CMS group. No significant group differences or increased rates of impairment were observed for behavioral and emotional outcomes. CONCLUSIONS: Survivors with CMS, compared with those without CMS, are rated as having significant deficits in overall or general adaptive functioning, with specific weakness in practical skills several years posttreatment. Findings from this study demonstrate the high risk for ongoing functional deficits despite acute recovery from symptoms of CMS, highlighting the need for intervention to mitigate such risk.

Current Diagnosis and Management of Acute Colonic Diverticulitis: What You Need To Know.

ABSTRACT: Acute colonic diverticulitis is a common disease treated by acute care surgeons. Acute uncomplicated colonic diverticulitis involves thickening of the colon wall and inflammatory changes and less commonly requires the expertise of a surgeon; many cases may be treated as an outpatient with or without antibiotics. Complicated diverticulitis involves phlegmon, abscess, peritonitis, obstruction, stricture, and/or fistula and usually requires inpatient hospital admission, treatment with antibiotics, and consideration for intervention including operative management. This review will discuss what the acute care surgeon needs to know about diagnosis and management of acute colonic diverticulitis.

Broadening their horizons: A rural and urban nursing student exchange program in primary care.

Educational strategies that allow students to experience patient care in both rural and urban settings are imperative to the recruitment and retention of nurses for medically underserved populations or health professional shortage areas. Two state schools of nursing (one urban-oriented and one rural-oriented) in the Mid-Atlantic region were awarded Health Resources and Service Administration (HRSA) project funding to educate nursing students and registered nurses in community-based primary care settings. This article will discuss an innovative rural-urban baccalaureate nursing student exchange model intended to increase understanding of enhanced RN roles in community-based primary care settings. Two project teams collaborated to create a new learning model, a rural-urban exchange, by implementing a Primary Care Camp. The camp included shared didactic content, reflection exercises, historical and cultural considerations, and clinical immersion to allow students in both programs to have on-site rural and urban learning experiences. Faculty collected informal voluntary student feedback through a debrief after their Primary Care Camp experience to assess their understanding of the enhanced RN Role in primary care and how it may affect their future nursing practice. Student feedback suggests that the students met project goals and appreciated the rural and urban exchange experience. This project is an innovative approach that offers guidance for implementing primary care education in a way that supports the current primary care RN role, builds the future workforce, and provides suggestions for replicability.

Emergency general surgery verification: Quality improvement and the case for optimal resources and process standards.

ABSTRACT: Patients with emergency general surgery (EGS) diagnoses comprise over 10% of all hospital admissions, resulting in a projected number of 4.2 million admissions for 2023. Approximately 25% will require emergency surgical intervention, half will sustain a postoperative complication, and 15% will have a readmission within the first 30 days of surgery. In the face of this growing public health burden and to better meet the needs of these acutely ill patients, it was recognized that a formal quality improvement program, including standardization of data collection and the development of systems of care specifically for EGS have been lacking. Establishing standardized processes for quality improvement, including a national databank, and maintaining adherence to these processes as ensured by a robust verification process has improved outcomes research and patient care in the field of trauma, another time-sensitive specialty. In response to this perceived deficit, the "Optimal Resources for Emergency General Surgery" was developed. An extension of the current National Surgical Quality Improvement Program platform, specifically for operative and non-operative EGS cases, was developed and implemented. A robust set of standards were outlined to verify EGS programs/services. Defining the elements of an effective EGS program and developing hospital and practice standards consolidated EGS as an integral component of Acute Care Surgery. The verification program addresses a societal need and allows hospitals to better organize EGS care delivery and benchmark their results nationally.

The interaction between geriatric and neighborhood vulnerability: Delineating prehospital risk among older adult emergency general surgery patients.

BACKGROUND: When presenting for emergency general surgery (EGS) care, older adults frequently experience increased risk of adverse outcomes owing to factors related to age ("geriatric vulnerability") and the social determinants of health unique to the places in which they live ("neighborhood vulnerability"). Little is known about how such factors collectively influence adverse outcomes. We sought to explore how the interaction between geriatric and neighborhood vulnerability influences EGS outcomes among older adults. METHODS: Older adults, 65 years or older, hospitalized with an AAST-defined EGS condition were identified in the 2016 to 2019, 2021 Florida State Inpatient Database. Latent variable models combined the influence of patient age, multimorbidity, and Hospital Frailty Risk Score into a single metric of "geriatric vulnerability." Variations in geriatric vulnerability were then compared across differences in "neighborhood vulnerability" as measured by variations in Area Deprivation Index, Social Vulnerability Index, and their corresponding subthemes (e.g., access to transportation). RESULTS: A total of 448,968 older adults were included. For patients living in the least vulnerable neighborhoods, increasing geriatric vulnerability resulted in up to six times greater risk of death (30-day risk-adjusted hazards ratio [HR], 6.32; 95% confidence interval [CI], 4.49-8.89). The effect was more than doubled among patients living in the most vulnerable neighborhoods, where increasing geriatric vulnerability resulted in up to 15 times greater risk of death (30-day risk-adjusted HR, 15.12; 95% CI, 12.57-18.19). When restricted to racial/ethnic minority patients, the multiplicative effect was four-times as high, resulting in corresponding 30-day HRs for mortality of 11.53 (95% CI, 4.51-29.44) versus 40.67 (95% CI, 22.73-72.78). Similar patterns were seen for death within 365 days. CONCLUSION: Both geriatric and neighborhood vulnerability have been shown to affect prehospital risk among older patients. The results of this study build on that work, presenting the first in-depth look at the powerful multiplicative interaction between these two factors. The results show that where a patient resides can fundamentally alter expected outcomes for EGS care such that otherwise less vulnerable patients become functionally equivalent to those who are, at baseline, more aged, more frail, and more sick. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level III.

Effects of gender on work-life balance satisfaction among trauma surgeons: A survey study.

BACKGROUND: Physician burnout rates are rising. Because dissatisfaction with work-life balance (WLB) is associated with burnout, improving this balance is a key solution. This cross-sectional survey study aims to evaluate factors associated with WLB in trauma surgeons, stratified by gender. METHODS: This is a secondary analysis, studying gender, of a AAST survey evaluating predictors of WLB in trauma surgeons. Survey topics include demographics, clinical practice, family, lifestyle, and emotional support. Subgroups were analyzed independently; primary outcome was WLB satisfaction. RESULTS: 292 AAST members completed the survey. Responses were stratified by gender (29% females, 71% males). Independent predictors of WLB satisfaction are: Females: more awake hours at home, having a job well-suited for them, better about meeting deadlines. Males: comfortable declining new tasks, fair compensation, healthy diet, workplace emotional support. CONCLUSION: Factors associated with WLB satisfaction in trauma surgeons are different based on gender. This information may help trauma surgeons mitigate burnout.

Estradiol Mediates Greater Germinal Center Responses to Influenza Vaccination in Female than Male Mice.

Adult females of reproductive ages develop greater antibody responses to inactivated influenza vaccine (IIV) than males. How sex, age, and sex steroid changes impact B cells and durability of IIV-induced immunity and protection over 4-months post-vaccination (mpv) was analyzed. Vaccinated adult females had greater germinal center (GC) B cell and plasmablast frequencies in lymphoid tissues, higher neutralizing antibody responses 1-4 mpv, and better protection against live H1N1 challenge than adult males. Aged mice, regardless of sex, had reduced B cell frequencies, less durable antibody responses, and inferior protection after challenge than adult mice, which correlated with diminished estradiol among aged females. To confirm that greater IIV-induced immunity was caused by sex hormones, four core genotype (FCG) mice were used, in which the testes determining gene, Sry, was deleted from ChrY and transferred to Chr3, to separate gonadal sex (i.e., ovaries or testes) from sex chromosome complement (i.e., XX or XY complement). Vaccinated, gonadal female FCG mice (XXF and XYF) had greater numbers of B cells, higher antiviral antibody titers, and reduced pulmonary virus titers following live H1N1 challenge than gonadal FCG males (XYM and XXM). To establish that lower estradiol concentrations cause diminished immunity, adult and aged females received either a placebo or estradiol replacement therapy prior to IIV. Estradiol replacement significantly increased IIV-induced antibody responses and reduced morbidity after the H1N1 challenge among aged females. These data highlight that estradiol is a targetable mechanism mediating greater humoral immunity following vaccination among adult females.

Bacterial heterogeneity and antibiotic persistence: bacterial mechanisms utilized in the host environment.

SUMMARYAntibiotic persistence, or the ability of small subsets of bacteria to survive prolonged antibiotic treatment, is an underappreciated cause of antibiotic treatment failure. Over the past decade, researchers have discovered multiple different stress responses and mechanisms that can promote antibiotic persistence. However, many of these studies have been completed in culture-based systems that fail to truly replicate the complexities of the host environment, and it is unclear whether the mechanisms defined in in vitro studies are applicable during host infection. In this review, we focus our discussion on recent studies that utilize a mixture of ex vivo culture systems and animal models to understand what stressors in the host environment are important for inducing antibiotic persistence. Different host stressors are involved depending on the anatomical niche the bacteria reside in and whether the host immune system is primed to generate a more robust response against bacteria, which can result in differing downstream effects on antibiotic susceptibility. Bacterial pathogens can also utilize specific strategies to reprogram their metabolism, which is vital for transitioning into an antibiotic-persistent state within host tissues. Importantly, we highlight that more attention is needed to establish guidelines for in vivo work on antibiotic persistence, particularly when identifying antibiotic-persistent subpopulations and distinguishing these phenotypes from antibiotic tolerance. Studying antibiotic persistence in the context of the host environment will be crucial for developing tools and strategies to target antibiotic-persistent bacteria and increase the efficacy of antibiotic treatment.

Changes in Older Adult Trauma Quality When Evaluated Using Longer-Term Outcomes vs In-Hospital Mortality.

Importance: Lack of knowledge about longer-term outcomes remains a critical blind spot for trauma systems. Recent efforts have expanded trauma quality evaluation to include a broader array of postdischarge quality metrics. It remains unknown how such quality metrics should be used. Objective: To examine the utility of implementing recommended postdischarge quality metrics as a composite score and ascertain how composite score performance compares with that of in-hospital mortality for evaluating associations with hospital-level factors. Design, Setting, and Participants: This national hospital-level quality assessment evaluated hospital-level care quality using 100% Medicare fee-for-service claims of older adults (aged ≥65 years) hospitalized with primary diagnoses of trauma, hip fracture, and severe traumatic brain injury (TBI) between January 1, 2014, and December 31, 2015. Hospitals with annual volumes encompassing 10 or more of each diagnosis were included. The data analysis was performed between January 1, 2021, and December 31, 2022. Exposures: Reliability-adjusted quality metrics used to calculate composite scores included hospital-specific performance on mortality, readmission, and patients' average number of healthy days at home (HDAH) within 30, 90, and 365 days among older adults hospitalized with all forms of trauma, hip fracture, and severe TBI. Main Outcomes and Measures: Associations with hospital-level factors were compared using volume-weighted multivariable logistic regression. Results: A total of 573 554 older adults (mean [SD] age, 83.1 [8.3] years; 64.8% female; 35.2% male) from 1234 hospitals were included. All 27 reliability-adjusted postdischarge quality metrics significantly contributed to the composite score. The most important drivers were 30- and 90-day readmission, patients' average number of HDAH within 365 days, and 365-day mortality among all trauma patients. Associations with hospital-level factors revealed predominantly anticipated trends when older adult trauma quality was evaluated using composite scores (eg, worst performance was associated with decreased older adult trauma volume [odds ratio, 0.89; 95% CI, 0.88-0.90]). Results for in-hospital mortality showed inverted associations for each considered hospital-level factor and suggested that compared with nontrauma centers, level 1 trauma centers had a 17 times higher risk-adjusted odds of worst (highest quantile) vs best (lowest quintile) performance (odds ratio, 17.08; 95% CI, 16.17-18.05). Conclusions and Relevance: The study results challenge historical notions about the adequacy of in-hospital mortality as the single measure of older adult trauma quality and suggest that, when it comes to older adults, decisions about how quality is evaluated can profoundly alter understandings of what constitutes best practices for care. Composite scores appear to offer a promising means by which postdischarge quality metrics could be used.

mSphere of Influence: If virulence is energetically costly, how can it be maintained?

Kimberly Davis works in the field of bacterial pathogenesis and studies heterogeneity in bacterial populations within host tissues. In this mSphere of Influence article, she reflects on how the paper "Stabilization of cooperative virulence by the expression of an avirulent phenotype" by M. Diard et al. (M. Diard et al., Nature 494:353-6, 2013, DOI: 10.1038/nature11913) impacted the way she thinks about bacterial population dynamics and the costs and benefits of producing virulence factors during infection.

An interprofessional geriatrics faculty development program: exploration of the barriers and facilitators of capstone projects.

Faculty development programs (FDPs) are an effective, evidence-based method of promoting knowledge, skills and self-efficacy of faculty. However, implementation and sustainability of curricular capstone projects developed by faculty as part of these programs are rarely reported. Challenges to sustaining programmatic implementation of interprofessional FDP curricular content into academic and clinical settings over time were not found in peer-reviewed literature. To better understand the sustained impact of our geriatrics-focused FDP, we explored barriers and facilitators to implementation and sustainability of capstone projects designed by faculty Scholars in our FDP. Thematic analysis of virtual interviews with 17 Scholars revealed several key factors that impacted the implementation and Dynamic sustainability of curricular projects. Three major themes and sub-themes were identified: Project Implementation (Supportive Factors, Hindering Factors and Filling in Gaps in the Field); Pedagogical Development (Enhancement of Skills and Culture Change); and Sustainability Impact (Project Sustainability, Career Development and Passing the Torch). Results suggest it is important to ensure logistical support, dedicated time, and organizational or institutional support. Implementation of geriatrics-focused FDPs provides an evidence-based approach to sustainability. Further study of the ongoing barriers and facilitators to sustainability is encouraged.

Routine post-operative labs and healthcare system burden in acute appendicitis.

BACKGROUND: Data from the National Health Expenditure Accounts have shown a steady increase in healthcare cost paralleled by availability of laboratory tests. Resource utilization is a top priority for reducing health care costs. We hypothesized that routine post-operative laboratory utilization unnecessarily increases costs and healthcare system burden in acute appendicitis (AA) management. METHODS: A retrospective cohort of patients with uncomplicated AA 2016-2020 were identified. Clinical variables, demographics, lab usage, interventions, and costs were collected. RESULTS: A total of 3711 patients with uncomplicated AA were identified. Total costs of labs ($289,505, 99.56%) and repletions ($1287.63, 0.44%) were $290,792.63. Increased LOS was associated with lab utilization in multivariable modeling, increasing costs by $837,602 or 472.12 per patient. CONCLUSIONS: In our patient population, post-operative labs resulted in increased costs without discernible impact on clinical course. Routine post-operative laboratory testing should be re-evaluated in patients with minimal comorbidities as this likely increases cost without adding value.

Alcohol withdrawal syndrome in trauma patients: a study using the Trauma Quality Program Participant User File.

Objective: To identify the rates and possible predictors of alcohol withdrawal syndrome (AWS) among adult trauma patients. Methods: This is a retrospective review of all adult patients (18 years or older) included in the 2017 and 2018 American College of Surgeons Trauma Quality Program Participant User File (PUF). The main outcomes were rates and predictors of AWS. Results: 1 677 351 adult patients were included in the analysis. AWS was reported in 11 056 (0.7%). The rate increased to 0.9% in patients admitted for more than 2 days and 1.1% in those admitted for more than 3 days. Patients with AWS were more likely to be male (82.7% vs. 60.7%, p<0.001), have a history of alcohol use disorder (AUD) (70.3% vs. 5.6%, p<0.001) and have a positive blood alcohol concentration (BAC) on admission (68.2% vs. 28.6%, p<0.001). In a multivariable logistic regression, history of AUD (OR 12.9, 95% CI 12.1 to 13.7), cirrhosis (OR 2.1, 95% CI 1.9 to 2.3), positive toxicology screen for barbiturates (OR 2.1, 95% CI 1.6 to 2.7), tricyclic antidepressants (OR 2.2, 95% CI 1.5 to 3.1) or alcohol (OR 2.5, 95% CI 2.4 to 2.7), and Abbreviated Injury Scale head score of ≥3 (OR 1.7, 95% CI 1.6 to 1.8) were the strongest predictors for AWS. Conversely, only 2.7% of patients with a positive BAC on admission, 7.6% with a history of AUD and 4.9% with cirrhosis developed AWS. Conclusion: AWS after trauma was an uncommon occurrence in the patients in the PUF, even in higher-risk patient populations. Level of evidence: IV: retrospective study with more than one negative criterion.

A novel rodent model of chronic spinal implant-associated infection.

BACKGROUND CONTEXT: Bacterial infection of spinal instrumentation is a significant challenge in spinal fusion surgery. Although the intraoperative local application of powdered vancomycin is common practice for mitigating infection, the antimicrobial effects of this route of administration are short-lived. Therefore, novel antibiotic-loaded bone grafts as well as a reliable animal model to permit the testing of such therapies are needed to improve the efficacy of infection reduction practices in spinal fusion surgery. PURPOSE: This study aims to establish a clinically relevant rat model of spinal implant-associated infection to permit the evaluation of antimicrobial bone graft materials used in spinal fusion. STUDY DESIGN: Rodent study of chronic spinal implant-associated infection. METHODS: Instrumentation anchored in and spanning the vertebral bodies of L4 and L5 was inoculated with bioluminescent methicillin-resistant Staphylococcus aureus bacteria (MRSA). Infection was monitored using an in vivo imaging system (IVIS) for 8 weeks. Spines were harvested and evaluated histologically, and colony-forming units (CFUs) were quantified in harvested implants and spinal tissue. RESULTS: Postsurgical analysis of bacterial infection in vivo demonstrated stratification between MRSA and phosphate-buffered saline (PBS) control groups during the first 4 weeks of the 8-week infection period, indicating the successful establishment of acute infection. Over the 8-week chronic infection period, groups inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU demonstrated significantly higher bioluminescence than groups inoculated with PBS control (p = 0.009 and p = 0.041 respectively). Histological examination at 8 weeks postimplantation revealed the presence of abscesses localized to implant placement in all MRSA inoculation groups, with the most pervasive abscess formation in samples inoculated with 1 × 105 MRSA CFU and 1 × 106 MRSA CFU. Quantification of CFU plated from harvested spinal tissue at 8 weeks post-implantation revealed the 1 × 105 MRSA CFU inoculation group as the only group with a significantly greater average CFU count compared to PBS control (p = 0.017). Further, CFU quantification from harvested spinal tissue was greater than CFU quantification from harvested implants across all inoculation groups. CONCLUSION: Our model demonstrated that the inoculation dosage of 1 × 105 MRSA CFU exhibited the most robust chronic infection within instrumented vertebral bodies. This dosage had the greatest difference in bioluminescence signal from control (p < 0.01), the lowest mortality (0% compared to 50% for samples inoculated with 1 × 106 MRSA CFU), and a significantly higher amount of CFUs from harvested spine samples than CFUs from control harvested spine samples. Further, histological analysis confirmed the reliability of this novel rodent model of implanted-associated infection to establish infection and biofilm formation of MRSA for all inoculation groups. CLINICAL SIGNIFICANCE: This model is intended to simulate the infection of instrumentation used in spinal fusion surgeries concerning implant locality and material. This model may evaluate potential antimicrobial and osteogenic biomaterials and investigate the relationship between implant-associated infection and failed fusion.