Chronic Infections of the Spine: A Systematic Review of Microbial Etiologies, Diagnostic Approaches, and Treatment Outcomes.

BACKGROUND: Chronic spinal infections are uncommon but potentially devastating conditions, frequently associated with delayed diagnosis, heterogeneous microbiology, and complex management. Existing evidence remains fragmented, and a comprehensive synthesis of microbial etiologies, diagnostic approaches, and treatment outcomes is needed.

METHODS: A systematic review was conducted in accordance with PRISMA guidelines. PubMed, Scopus, Web of Science, and Embase were searched for studies published between October 2015 and September 2025 involving adult patients with chronic spinal infections. Data were extracted on causative pathogens, diagnostic modalities, medical and surgical interventions, and clinical outcomes. Risk of bias was assessed using standardized methodological criteria.

RESULTS: Fifty-five studies comprising 3,036 patients were included. Mycobacterium tuberculosis was the most frequently identified pathogen, followed by Brucella species and pyogenic bacteria. Metagenomic next-generation sequencing (mNGS) demonstrated the highest diagnostic yield, with reported sensitivities ranging from 82% to 92%, and showed particular utility in detecting mixed or atypical infections. Biomarker-based and RNA-derived assays demonstrated promising performance in differentiating tuberculous spondylitis from other spinal conditions. Surgical interventions, including minimally invasive and combined approaches, were associated with high fusion and neurological recovery rates.

CONCLUSIONS: Chronic spinal infections show marked microbiological heterogeneity. Integrating molecular diagnostics with tailored surgical and antimicrobial strategies may improve diagnostic accuracy and clinical outcomes.