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 Background Spinal implant infections (SII) are serious complications following instrumented spinal fusion. Debridement with implant retention requires antibiotic therapy, yet the optimal duration remains unclear. We assessed whether longer antibiotic duration is associated with reduced risk of treatment failure. Methods We conducted a multicenter retrospective cohort study of adult patients diagnosed with acute postoperative SII (≤90 days from index surgery) between January 1, 2017, and December 31, 2022. All patients underwent debridement with implant retention. Treatment failure was defined as unplanned reoperation, clinical recurrence, or infection-related death. A Cox proportional hazards model assessed whether being on antibiotics was protective, treating antibiotic use as a time-dependent covariate, adjusting for relevant clinical variables, and including death not attributable to infection as a competing event. A second Cox model evaluated whether shorter antibiotic duration was associated with increased risk of failure with landmark analysis at six weeks. Results There were 531 patients included in the study. Patient demographics are described in Table 1. During a median follow-up of 1,168 days (IQR 576-1,817), 151 patients experienced treatment failure. There was a non-significant trend toward decreased hazard of failure while on antibiotics (HR 0.70; 95% CI 0.46–1.05; p=0.087). Among 363 patients without early failure, 60 (16.5%) received ≤6 weeks of antibiotics and 303 (83.5%) received >6 weeks. Longer antibiotic duration was not associated with a differential risk of failure (HR 0.75, 95% CI 0.43–1.33; p=0.34). Conclusion Continuing antibiotic therapy after debridement and implant retention may help reduce the risk of treatment failure in SII. However, it remains unclear whether extending antibiotic treatment beyond a certain duration continues to offer additional benefits. Prospective studies are needed to better define the optimal duration and approach to antibiotic therapy in these scenarios. Disclosures Sandra B. Nelson, MD, UpToDate Wolters Kluwer Health: Author, Editor

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 There are anatomical, pharmacokinetic, and joint biomechanical differences between males and females. Whether these differences result in differing presentation, treatment tolerability and outcomes in periprosthetic joint infection (PJI) has not been widely evaluated. Methods We undertook a retrospective case matched study of patients with staphylococcal PJI managed with two-stage exchange arthroplasty. In order to control for differences other than sex which may influence outcome or presentation, males and females were case-matched for age, causative organism (Coagulase-negative staphylococci vs Staphylococcus aureus) and joint involved. The two matched groups were analyzed for differences in duration of symptoms, inflammatory markers, duration of hospital stay, antimicrobial side effects, post-operative complications and recurrence rate. Recurrence of infection was defined as per Musculoskeletal Infection Society criteria for PJI and included both relapse with original microorganism or with an additional organism. Results 78 pairs of males and females with staphylococcal PJI were successfully matched. There were no significant baseline differences by sex, except for greater use of chronic immunosuppression among females (16.7% vs. 4.1%; p=0.012). Clinical characteristics and outcomes of the patients are summarized in table 1. We did not detect a statistically significant between the outcomes of the two groups. Overall, 16 recurrent infections occurred during a median follow-up time of 2.9 (IQR: 1.5 - 5.3) years. The 3-year cumulative incidence of treatment failure depicted in figure 1 was 16.1% for females, compared with 8.8% for males (p=0.434). Conclusion Success rates for PJI treated with two-stage exchange arthroplasty are high consistent with previously reported literature. A larger cohort of patients may be required to detect differences in relapse rates. This study included only staphylococcal PJI and was thus unable to evaluate the differences in microbiology of PJI between males and females, which could also impact outcomes. This retrospective case-matched study did not detect any significant differences in outcomes between males and females with staphylococcal PJI who underwent two stage exchange arthroplasty. Disclosures Gina A. Suh, M.D., Adaptive Phage Therapeutics (APT): Grant/Research Support|Adaptive Phage Therapeutics (APT): Dr. Suh received grants and has an equity and royalty-bearing know-how agreement with Adaptive Phage Therapeutics but is unrelated to project Aaron J. Tande, M.D., Uptodate: Dr Tande has received an honorarium from Uptodate for medical writing unrelated to this project.