Percutaneous Disc Biopsy versus Bone Biopsy for the Identification of Infectious Agents in Osteomyelitis/Discitis

Purpose To determine whether sampling of the disc or bone is more likely to yield positive tissue culture results in patients with vertebral discitis and osteomyelitis (VDO). Materials and Methods Retrospective review was performed of consecutive patients who underwent vertebral disc or vertebral body biopsy at a single institution between February 2019 and May 2023. Inclusion criteria were age ≥18 years, presumed VDO on spinal magnetic resonance (MR) imaging, absence of paraspinal abscess, and technically successful percutaneous biopsy with fluoroscopic guidance. The primary outcome was a positive biopsy culture result, and secondary outcomes included complications such as nerve injury and segmental artery injury. Results Sixty-six patients met the inclusion criteria; 36 patients (55%) underwent disc biopsy, and 30 patients (45%) underwent bone biopsy. Six patients required a repeat biopsy for an initially negative culture result. No significant demographic, laboratory, antibiotic administration, or pain medication use differences were observed between the 2 groups. Patients who underwent bone biopsy were more likely to have a history of intravenous drug use (26.7%) compared with patients who underwent disc biopsy (5.5%; P = .017). Positive tissue culture results were observed in 41% of patients who underwent disc biopsy and 15% of patients who underwent bone biopsy (P = .016). No vessel or nerve injuries were detected after procedure in either group. Conclusions Percutaneous disc biopsy is more likely to yield a positive tissue culture result than vertebral body biopsy in patients with VDO.