Diagnostic value of percutaneous paramedian small-angle lateral intervertebral foramen Kambin's triangle approach for lumbar puncture biopsy combined with tNGS-based multimodal etiological diagnosis in early spinal infection: a multicenter retrospective diagnostic yield study

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• Picked for Pathology and Forensic Medicine (paper of the day, 31 July 2026).

Abstract

OBJECTIVE: To validate the safety and multicenter technical feasibility of an innovatively designed percutaneous paramedian small-angle lateral intervertebral foramen Kambin's triangle approach for lumbar puncture biopsy in early spinal infection (SI), and to evaluate the diagnostic yield and etiological identification rate of the tNGS-based multimodal etiological detection protocol using specimens obtained via this approach. METHODS: This was a multicenter retrospective cohort study that enrolled 94 consecutive patients with SI who underwent the aforementioned puncture biopsy at 3 medical centers between January 2024 and January 2026. We systematically evaluated the procedure-related indicators and perioperative complications of this puncture approach. All puncture specimens were synchronously subjected to histopathological examination, routine bacterial culture, Xpert MTB/RIF assay, and tNGS detection. With the final comprehensive clinical diagnosis as the reference standard, we compared and analyzed the diagnostic performance of each detection method. RESULTS: All 94 patients successfully completed biopsy via this modified puncture approach, with an overall puncture-related complication rate of only 7.45%. All adverse events were mild, and no severe complications occurred, and the approach was feasible and appeared safe in this retrospective cohort, though prospective validation across multiple operators is warranted before widespread clinical adoption. For etiological detection, the overall positive rate of tNGS reached 87.23%, which was significantly higher than that of routine bacterial culture (25.53%), specific histopathological diagnosis (17.02%), and Xpert MTB/RIF assay (17.02%) (all P < 0.0001). Meanwhile, tNGS maintained a stable and high detection rate across all major SI subtypes. The tNGS-centered multimodal combined detection achieved an overall positive rate of 91.49%. Notably, in early-stage cases where histopathology only indicated non-specific inflammatory cell infiltration, the combined detection achieved an etiology confirmation rate of 95.65%, effectively compensating for the deficiency of detection methods in early diagnosis. CONCLUSIONS: The puncture approach designed in this study addresses the core bottleneck of specimen acquisition in early SI. The tNGS-based multimodal detection system using this approach has excellent diagnostic performance in early-stage infection, and can provide critical evidence-based support for the early accurate diagnosis and treatment as well as targeted antimicrobial therapy of SI.

Abstract as published, via PubMed.