SRS232 - The biopsy dilemma in spinal infections: timing of antibiotics and diagnostic yield

Abstract Introduction Spinal infections such as spondylodiscitis cause severe morbidity if diagnosis or treatment is delayed. Microbiological confirmation is essential for guiding therapy, but culture yields vary by biopsy technique and prior antibiotic exposure. The impact of antibiotics on diagnostic yield, particularly between CT-guided and open biopsy, remains unclear. Materials and Methods A systematic review was conducted per PRISMA guidelines, searching MEDLINE, EMBASE, Web of Science, Cochrane Library, and Scopus through June 2025. Eligible studies included adults or children with suspected spinal infection undergoing CT-, fluoroscopy-, or open biopsy, with or without prior antibiotics. The primary outcome was culture positivity. Risk of bias was assessed using ROBINS-I, and pooled risk ratios (RR) with 95% confidence intervals (c.i.) were calculated with fixed- or random-effects models. Results Thirty-eight studies (>2000 patients) met inclusion. Nine comparative studies (n = 796) showed prior antibiotics significantly reduced culture yield (59.6% versus 39.2%; RR = 0.74, 95% c.i.: 0.63–0.86, P = 0.0001; I² = 0%), particularly within 72 h of initiation. Open biopsy achieved the highest yield (76.1%) compared with CT-guided (50.0%) and fluoroscopy-guided biopsy (28.6%). Pooled analysis confirmed superiority of open over CT-guided biopsy (RR = 0.66, 95% c.i.: 0.57–0.76, P < 0.00001), while CT and fluoroscopy showed no significant difference. Conclusions Antibiotics reduce microbiological yield in spinal infections, especially in the first 72 h. Open biopsy consistently outperforms percutaneous techniques, even after exposure. A biopsy-first approach should be prioritized in stable patients, with early surgical biopsy considered when antibiotics cannot be delayed. Standardized protocols and prospective studies are needed to refine diagnostic pathways.