Tobert, Daniel G

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

Study Design Narrative Review. Objectives To summarize the scientific contributions generated from the AO Spine Knowledge Forum Tumor (AOSKFT) databases, focusing on primary spine tumors, and highlight key findings, research trends, and future directions. Methods Data from the Primary Tumor Retrospective (PT-Retro) and Primary Tumor Research Outcome Network (PTRON) registries were analyzed. The nineteen studies included were peer-reviewed manuscripts focused on primary spine tumors, excluding abstracts, book chapters, systematic reviews, and metastatic studies. Results The PT-Retro registry compiled data from 1495 patients across 18 primary tumor histologies, offering insights into recurrence, survival, and treatment paradigms. Key findings emphasize the importance of Enneking-appropriate (EA) resection in improving survival and reducing recurrence in tumors such as chordoma, chondrosarcoma, and osteosarcoma. Genetic markers, including hTERT promoter mutations and rs2305089 SNP, were linked to prognosis in specific histologies. Benign tumors, such as giant cell tumors and aneurysmal bone cysts, demonstrated variable outcomes with different surgical approaches and selective arterial embolization. Conclusions The AOSKFT registries have significantly advanced knowledge in primary spine tumor management, emphasizing preoperative staging, surgical margins, and multidisciplinary approaches. International, multicentric registries are essential for studying rare diseases like primary spine tumors, enabling robust data collection, improved statistical power, and broader applicability of findings across diverse clinical settings. Ongoing prospective data collection through PTRON will further refine evidence-based care for these rare and challenging conditions.

Abstract Background To determine if dose escalation improves outcomes for chondrosarcomas (CHS) of the base of the skull (BOS) and the cervical spine (CS). Methods A prospective, randomized, dose-escalation trial was designed for patients with CHS of the BOS and CS. Patients were randomly assigned to 70 Gy (RBE) or 76 Gy (RBE). The primary endpoint was local failure (LF). Secondary endpoints included overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS), and treatment-related toxicities. Results Between 1987 and 2007, 105 patients were randomized, median follow-up was 29.2 years (IQR, 26.7-32.4). Forty-six patients were assigned to 70 Gy (RBE) and 59 were assigned to 76 Gy (RBE). LF at 5-, 10-, and 20 years were 7%, 9%, and 11% for 70 Gy (RBE), and 10%, 15%, and 19% for 76 Gy (RBE) (P = .16). Like LF rates, there was no benefit in dose escalation for OS (P = .28) and CSS (P = .22). Progression-free survival at 5-, 10-, and 20 years was 93%, 89%, and 77% for the low-dose group and 83%, 71%, and 59% for the high-dose group (P = .069). Late RT injury ≥ grade 3 was reported in a total of 19 (18%) patients across both dose levels, with 11% in the low-dose group and 24% in the high-dose group (P = .13). Conclusions This is the first and largest trial of patients with grade I/II BOS and CS CHS evaluating dose escalation for tumor control. Proton-based RT is effective and safe for these tumors, but there is no apparent benefit in dose escalation. Clinical Trial Information NCT00592748.