Tai, Don Bambino Geno

Abstract Background Postoperative spinal implant infections (PSIIs) are a serious complication of instrumented spinal fusion. Although debridement with implant retention is standard for early infection, the optimal duration of antimicrobial therapy remains uncertain. Methods We conducted a multicenter retrospective cohort study across 10 US academic centers, including adults with early PSII (≤90 days after fusion surgery) from 2017 to 2021. We excluded patients who experienced treatment failure within 6 weeks of debridement. The primary outcome was treatment failure. Antibiotic therapy effect was analyzed as a time-varying exposure using adjusted Cox proportional hazards models. Secondary analyses included 12-week landmark and clone-censor-weighted models to compare durations ≤ 12 weeks versus >12 weeks. Results A total of 116 patients out of 499 (23.2%) experienced treatment failure during a median follow-up of 3.2 years. Among patients who remain failure-free 6 weeks from debridement, being on antibiotics was not associated with treatment failure (adjusted hazard ratio [aHR] 0.71; 95% CI .48–1.07; P = .10). In a 12-week landmark analysis limited to 359 patients who were not on indefinite suppressive antibiotic therapy, treatment durations > 12 weeks did not significantly reduce the risk of failure (aHR 1.01; 95% CI .62–1.64; P = .99). Results were consistent in the clone-censor-weight sensitivity analysis (aHR 0.85; 95% CI .62–1.16; P = .30). Conclusions Prolonged antibiotic therapy was not associated with improved outcomes in early PSII managed with debridement and implant retention. These results support shorter, individualized antibiotic courses in patients with adequate surgical source control.

Abstract Spinal implant infections are a serious complications of instrumented spinal fusion surgeries, carrying high morbidity and complex management challenges. Early postoperative infections may manifest with wound-healing issues, back pain, and fevers. Magnetic resonance imaging (MRI) is the preferred imaging modality, but can be limited by metal artifacts. For cases with stable implants, surgical debridement with implant retention combined with at least 12 weeks of antibiotics is currently considered appropriate treatment. Staphylococcal infections are ideally treated with biofilm-active antibiotics. Suppressive antibiotic therapy can be considered when surgical debridement has been delayed or is incomplete, and for those who are poor surgical candidates for another surgery. Chronic infections may present insidiously with implant failure or pseudarthrosis; implant removal or revision is generally pursued. As current guidance is heavily based on the periprosthetic joint infection literature and low-level studies on spinal implant infections, further research on optimizing diagnostic and treatment approaches is needed.

Abstract Background The first-line management strategy for acute periprosthetic joint infections (PJIs) is debridement, antibiotics, and implant retention (DAIR). Suppressive antibiotic therapy (SAT) after DAIR is proposed to improve outcomes, yet its efficacy remains under scrutiny. Methods We conducted a multicenter retrospective study in patients with acute PJI of the hip or knee who were treated with DAIR in centers from Europe and the United States. We analyzed the effect of SAT using a Cox model landmarked at 12 weeks. The primary covariate of interest was SAT, which was analyzed as a time-varying covariate. Patients who experienced treatment failure or were lost to follow-up within 12 weeks were excluded from the analysis. Results The study included 510 patients with 66 treatment failures with a median follow-up of 801 days. We did not find a statistically significant association between SAT and treatment failure (hazard ratio, 1.37; 95% CI, .79–2.39; P = .27). Subgroup analyses for joint, country cohort, and type of infection (early or late acute) did not show benefit for SAT. Secondary analysis of country cohorts showed a trend toward benefit for the US cohort (hazard ratio, 0.36; 95% CI, .11–1.15; P = .09), which also had the highest risk of treatment failure. Conclusions The utility of routine SAT as a strategy for enhancing DAIR's success in acute PJI remains uncertain. Our results suggest that SAT's benefits might be restricted to specific groups of patients, underscoring the need for randomized controlled trials. Identifying patients most likely to benefit from SAT should be a priority in future studies.

Antimicrobial therapy is an essential practice within medicine. Over the last 4 years, complex outpatient antimicrobial therapy (COpAT) with oral antimicrobials has become a rapidly developing area of practice and is non-inferior to outpatient parenteral antimicrobial therapy (OPAT) in certain infectious syndromes. Currently, the available literature does not describe the implementation of oral antimicrobials within the current outpatient antimicrobial therapy process. Throughout this article, the authors present a review of current literature, a proposed definition of COpAT and offer methods readers can utilize to implement an integrated COpAT/OPAT program with oral antimicrobial-specific monitoring within their current practice.

Abstract Background Cutibacterium acnes can cause spinal implant infections. However, little is known about the optimal medical management and outcomes of C. acnes spinal implant infections (CSII). Our study aims to describe the management of patients with CSII and evaluate the clinical outcomes. Methods We performed a retrospective cohort study of patients aged 18 years or older who underwent spinal fusion surgery with instrumentation between January 1, 2011, and December 31, 2020, and whose intraoperative cultures were positive for C. acnes. The primary outcome was treatment failure based on subsequent recurrence, infection with another organism, or unplanned surgery secondary to infection. Results There were 55 patients with a median follow-up (interquartile range) of 2 (1.2–2.0) years. Overall, there were 6 treatment failures over 85.8 total person-years, for an annual rate of 7.0% (95% CI, 2.6%–15.2%). Systemic antibiotic treatment was given to 74.5% (n = 41) of patients for a median duration of 352 days. In the subgroup treated with systemic antibiotics, there were 4 treatment failures (annual rate, 6.3%; 95% CI, 1.7%–16.2%), all of which occurred while on antibiotic therapy. Two failures occurred in the subgroup without antibiotic treatment (annual rate, 8.8%; 95% CI, 1.1%–31.8%). Conclusions Our study found that the estimated annual treatment failure rate was slightly higher among patients who did not receive antibiotics. Of the 6 failures observed, 4 had recurrence of C. acnes either on initial or subsequent treatment failures. More studies are warranted to determine the optimal duration of therapy for CSII.

Abstract Background Deep brain stimulator (DBS)–related infection is a recognized complication that may significantly alter the course of DBS therapy. We describe the Mayo Clinic Rochester experience with DBS-related infections. Methods This was a retrospective study of all adults (≥18 years old) who underwent DBS-related procedures between 2000 and 2020 at the Mayo Clinic Rochester. Results There were 1087 patients who underwent 1896 procedures. Infection occurred in 57/1112 (5%) primary DBS implantations and 16/784 (2%) revision surgeries. The median time to infection (interquartile range) was 2.1 (0.9–6.9) months. The odds of infection were higher with longer operative length (P = .002), higher body mass index (BMI; P = .006), male sex (P = .041), and diabetes mellitus (P = .002). The association between infection and higher BMI (P = .002), male sex (P = .016), and diabetes mellitus (P = .003) remained significant in a subgroup analysis of primary implantations but not revision surgeries. Infection was superficial in 17 (23%) and deep in 56 (77%) cases. Commonly identified pathogens were Staphylococcus aureus (65%), coagulase-negative staphylococci (43%), and Cutibacterium acnes (45%). Three device management approaches were identified: 39 (53%) had complete device explantation, 20 (27%) had surgical intervention with device retention, and 14 (19%) had medical management alone. Treatment failure occurred in 16 (23%) patients. Time-to-event analysis showed fewer treatment failures with complete device explantation (P = .015). Only 1 individual had complications with brain abscess at failure. Conclusions Primary DBS implantations had higher rates of infection compared with revision surgeries. Complete device explantation was favored for deep infections. However, device salvage was commonly attempted and is a reasonable approach in select cases given the low rate of complications.

Abstract Background Image-guided biopsies in patients with suspected native vertebral osteomyelitis (NVO) are recommended to establish the microbiological diagnosis and guide antibiotic therapy. Despite recent advances, the microbiological yield of this procedure remains between 48% and 52%. A better understanding of factors associated with this low yield may lead to improved microbiological diagnosis. Methods We retrospectively identified patients with suspected NVO undergoing image-guided biopsies from January 2011 to June 2021 at our institution. Two hundred nine patients undergoing 248 percutaneous biopsies were included. Demographic data, biopsy and microbiologic techniques, clinical characteristics, and antibiotic use were collected. Multivariable logistic regression analysis was conducted to determine factors associated with microbiological yield. Results A total of 110 of 209 (52.6%) initial image-guided biopsies revealed positive microbiological results. This number increased to 121 of 209 (57.9%) when repeat image-guided biopsies were included. In multivariable analysis, aspiration of fluid was associated with a 3-fold increased odds of yielding a positive result (odds ratio [OR], 3.13; 95% confidence interval [CI], 1.39–7.04; P = .006), whereas prior antibiotic use was associated with a 3-fold decreased yield (OR, 0.32; 95% CI, .16–.65; P = .002). A univariate subgroup analysis revealed a significant association between the length of the antibiotic-free period and microbiological yield, with the lowest rates of pathogen detection at 0–3 days and higher rates as duration increased (P = .017). Conclusions Prior antibiotic use in patients with suspected NVO was associated with a decrease in the microbiological yield of image-guided biopsies. An antibiotic-free period of at least 4 days is suggested to maximize yield. Successful fluid aspiration during the procedure also increases microbiological yield.

Abstract Background The optimal duration of antibiotic therapy after debridement and implant retention (DAIR) for periprosthetic joint infections (PJIs) is debated. Furthermore, the best antibiotic regimens for staphylococcal PJI are also unclear. In this study, we evaluated the impact of antibiotic therapy duration on the risk of failure. We assessed the utility of rifampin-based regimens for staphylococcal PJI managed with DAIR. Methods We performed a retrospective cohort study of patients 18 years and older diagnosed with hip and knee PJI who underwent DAIR between January 1, 2008 and 31 December 31, 2018 at Mayo Clinic, USA. The outcome was failure of DAIR. For statistical analysis, joint-stratified Cox regression models adjusted for age, sinus tract, symptom duration, and primary/revision arthroplasty were performed. Results We examined 247 cases of PJI with a median follow-up of 4.4 years (interquartile range [IQR], 2.3–7) after DAIR. The estimated 5-year cumulative incidence of failure was 28.1% (n = 65). There was no association between the duration of intravenous (IV) antibiotics (median 42 days; IQR, 38–42) and treatment failure (P = .119). A shorter duration of subsequent oral antibiotic therapy was associated with a higher risk of failure (P = .005; eg, 90-day vs 1-year duration; hazard ratio [HR], 3.50; 95% confidence interval [CI], 1.48–8.25). For staphylococcal knee PJI, both the use and longer duration of a rifampin-based regimen were associated with a lower risk of failure (both P = .025). There was no significant association between fluoroquinolone (FQ) use and failure (HR, 0.62; 95% CI, .31–1.24; P = .172). Conclusions The duration of initial IV antibiotic therapy did not correlate with treatment failure in this cohort of patients. Rifampin use is recommended for staphylococcal knee PJI. There was no apparent benefit of FQ use in staphylococcal PJI.