Diagnostic yield of 8G versus 11G transpedicular vertebral biopsy needles in suspected tuberculous spondylitis: a prospective randomized controlled study.

AIM: To compare the diagnostic yield of 8G and 11G bone biopsy needles in tubercular spondylitis (TBS). MATERIALS AND METHODS: 50 patients (mean age-40. years; males-27), suspected of TBS based on clinical and MRI features, underwent transpedicular biopsies under fluoroscopic guidance with 8G or 11G needles after randomization. The samples were evaluated on histology (chronic inflammation, granulomas, caseous necrosis and giant cells), GeneXpert, Polymerase Chain Reaction (PCR) and liquid cultures and categorised into diagnostic, non-specific and inadequate groups. Any procedure related complications (pneumothorax, puncture site infection, hematoma or increased pain) were recorded. RESULTS: There were 25 patients in each group. One patient in the 8G group experienced procedure-related pneumothorax. Of the three microbiological tests (GeneXpert, PCR, Liquid Culture), at least one test was found to be positive in 32% (n=8) of 8G group and 24% (n=6) of the 11G group samples (p>0.05). Histopathology was suggestive of tuberculosis for TB in 40% (n=10) of 8G group and 36% (n=9) of 11G group samples (p=0.88). Overall, the samples in 8G and 11G groups were diagnostic in 13 and 12 patients, non- specific in 10 and 9 patients, and inadequate in 2 and 4 patients respectively, with no statistically significant difference between groups (p=0.62). CONCLUSION: The study showed no significant difference in complications and diagnostic yield of biopsies performed using 8G and 11G needles in patients with tuberculous spondylitis.