The utility of image-guided percutaneous needle aspiration biopsy for the diagnosis of spontaneous vertebral osteomyelitis: A systematic review and meta-analysis

Background context Spontaneous vertebral osteomyelitis (SVOM) is mostly acquired via hematogenous seeding. Diagnosis of SVOM is often delayed because of the insidious nature and rarity of this disease. The microbiological yield of image-guided needle biopsy varies between 36% and 91%. The utility and accuracy of this procedure have not been systematically reviewed.

Purpose To systematically review and assess the diagnostic accuracy of image-guided spinal biopsy for SVOM in adults when compared with combined reference standards.

Study design A systematic review and meta-analysis.

Sample Seven retrospective studies involving 482 patients with clinical and/or radiologic suspicion of SVOM who underwent image-guided spinal biopsy were included.

Outcome measures The primary outcome measure was diagnostic odds ratio (DOR). Other outcomes included likelihood ratio of a positive test (LRP), likelihood ratio of a negative test (LRN), sensitivity, and specificity.

Methods We searched in six medical databases through September 1, 2013 for studies evaluating the performance of image-guided spinal biopsy for SVOM with no limits on language or publication date. Combined reference standards, which included histopathologic findings consistent with vertebral osteomyelitis, identifications of pathogens from open surgery and/or blood cultures, and/or evidence of clinical and radiologic improvement after empiric antimicrobial therapy, were used for comparison. The random-effect model was used for meta-analysis. Two reviewers independently selected the studies.

Results Three hundred fifty-eight potentially relevant studies were identified. Seven studies were included in our analysis. Two studies that used only single reference standard were excluded in the sensitivity analysis, and five studies involving 352 patients were pooled. Image-guided spinal biopsy had a DOR of 45.50 (95% confidence interval [CI], 13.66-151.56), an LRP of 16.76 (95% CI, 5.51-50.95), an LRN of 0.39 (95% CI, 0.24-0.64), a sensitivity of 52.2% (95% CI, 45.8-58.5), and a specificity of 99.9% (95% CI, 94.5-100). This is based on the assumption that combined reference standards are a valid standard for comparison.

Conclusions Image-guided spinal biopsy is highly specific and performs well in predicting SVOM, but has a moderate accuracy for ruling out this diagnosis. This procedure should be considered in the diagnostic work-up of adults suspected with SVOM.