Clinical utility of metagenomic next-generation sequencing in diagnosing spinal infections: a systematic review and meta-analysis

Spinal infection (SI) presents a major diagnostic challenge due to nonspecific clinical features and the limitations of conventional culturing techniques. Metagenomic next-generation sequencing (mNGS) has recently emerged as a valuable tool that enables broad, unbiased pathogen detection. This meta-analysis evaluated the diagnostic performance of mNGS for SI diagnosis, comparing it with conventional culturing techniques, with a particular focus on its role in spinal tuberculosis (TB) diagnosis. A thorough literature search was conducted in PubMed, Web of Science, the Cochrane Library, and Scopus databases to retrieve potentially relevant articles. Data on diagnostic performance, including pathogen detection rate (PDR), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were extracted and analyzed. To assess the risk of bias of the included studies, the quality assessment of diagnostic accuracy studies 2 (QUADAS-2) tool was used. Subgroup analyses were used to evaluate the performance of mNGS in spinal TB. Meta-regression analysis was performed to account for covariate effects on diagnostic performance. A total of 17 Chinese studies with 1788 patients were included. In SI diagnosis, mNGS showed a significantly greater PDR than conventional culturing techniques (RR: 2.43; 95% CI: 1.73–3.43; p = 0.0001; I² = 88.6%). mNGS exhibited higher sensitivity (81% vs. 33%) and NPV (60% vs. 36%) indicating higher reliability in excluding infection, while conventional culturing techniques exhibited higher specificity (82% vs. 76%) and PPV (90% vs. 85%). In spinal TB, mNGS showed higher sensitivity (75% vs. 41%) and NPV (87% vs. 74%) while maintaining comparable specificity (99% vs. 100%) and PPV (94% vs. 100%). This meta-analysis confirms that mNGS provides superior sensitivity, broader pathogen coverage, and faster diagnostic capability than conventional culturing techniques, particularly in spinal TB, where early detection is critical. Nevertheless, these findings should be interpreted cautiously, as the included studies were limited by retrospective designs, geographic bias, and inconsistent diagnostic reference standards. While mNGS represents a valuable adjunct to standard diagnostics, further prospective multicenter studies, cost reduction, and standardized protocols are required to optimize its integration into clinical practice.