C-arm-guided percutaneous biopsy combined with mNGS: a dual-modality strategy for optimizing diagnosis and targeted management of spinal infections

Spinal infections pose diagnostic dilemmas owing to nonspecific early symptoms (e.g., back pain and fever) overlapping with degenerative, neoplastic, or inflammatory conditions, resulting in high misdiagnosis rates. Metagenomic next-generation sequencing (mNGS) offers rapid culture-independent pathogen detection, and its clinical utility in spinal infections when integrated with C-arm-guided percutaneous biopsy remains inadequately characterized. To evaluate the diagnostic value of integrating C-arm-guided percutaneous biopsy with mNGS and conventional microbial culture for spinal infections. A retrospective, single-center study was conducted on 34 suspected cases of spinal infections. Specimens obtained via C-arm-guided percutaneous biopsy were subjected to mNGS, microbial culture, and clinical correlation analysis to establish a definitive diagnosis. The diagnostic performance metrics of mNGS and microbial culture were compared. mNGS demonstrated a significantly higher overall detection rate (91.18%) than microbial culture (55.88%) (p < 0.001). Subgroup analysis based on needle trajectories (parapedicular vs. transpedicular approaches) revealed no statistically significant difference in pathogen detection rates between the two methods (p > 0.05), indicating that the needle trajectory did not affect diagnostic outcomes. Both approaches achieved comparable efficacies under C-arm guidance. mNGS combined with C-arm-guided percutaneous biopsy significantly improves pathogen detection rates over traditional cultures, offering high diagnostic accuracy for complex spinal infections regardless of the biopsy approach. The clinical integration of imaging and laboratory data is essential for optimizing interpretation and avoiding diagnostic pitfalls. While mNGS costs approximately 4500 RMB per test versus 150 RMB for culture at our institution, early targeted therapy reduced the average hospitalization by 4–6 days, yielding net cost savings of 2000 RMB per case based on local hospitalization fees (1300 RMB/day).