Abstract: Objective To explore the application value of modified percutaneous intervertebral foraminal biopsy under C-arm guidance combined with metagenomics next-generation sequencing(mNGS)in the early diagnosis of lumbar disc infection. Methods A retrospective analysis was conducted on the clinical data of 179 patients suspected of having lumbar disc infection admitted to the Second Department of Orthopedics(Bone Infection), Shandong Public Health Clinical Center Affiliated to Shandong University from October 2020 to November 2023. All patients underwent puncture under C-arm guidance, with 90 cases employed the conventional percutaneous kyphoplasty puncture system(conventional group)and 89 cases utilized the improved percutaneous transforaminal biopsy system(improved group). Cultures for aerobic and anaerobic bacteria, acid-fast bacilli, and fungi, as well as routine drug susceptibility testing, mNGS, and histopathological examination were performed for each patient. The diagnostic sensitivity of puncture biopsy, operative time, fluoroscopy frequency, and incidence of immediate complications were compared between the two biopsy systems. Results There were no statistically significant differences between the two groups in baseline clinical characteristics such as gender, age, body mass index(BMI), proportion of patients with hypertension and diabetes, and preoperative C-reactive protein(CRP)and erythrocyte sedimentation rate(ESR)(P>0.05), indicating good comparability. However, there was a significant difference in the distribution of surgical segments(P=0.027). Regarding the main efficacy indicators, there were no statistically significant differences in the diagnostic sensitivity of puncture biopsy between the two groups(P>0.05), suggesting that the modified biopsy technique was comparable to the traditional technique in terms of pathogen detection efficacy. Safety analysis showed no statistically significant differences in the incidence of complications and operation time between the two groups(P>0.05); however, in terms of procedural characteristics, the modified group(8.04±0.94)overall, had slightly more fluoroscopy sessions than the traditional group(7.53±0.75)(P<0.001). Overall, the modified biopsy technique could achieve a level of efficacy comparable to the traditional method in early etiological diagnosis. Conclusion The improved percutaneous transforaminal biopsy combined with mNGS is a minimally invasive method for diagnosing early lumbar disc infection, characterized by high safety and a high diagnostic yield. It provides a robust and reliable optimized diagnostic pathway for clinical practice and holds significant clinical application value. Its effectiveness warrants further validation through studies with larger sample sizes and longer follow-up periods.

Key words: Intervertebral disc infection, Percutaneous puncture, Spinal biopsy, Spine, Pathology, Metagenomics next-generation sequencing