Association between sciatica and microbial infection: true infection or culture contamination?

STUDY DESIGN: Discs were cultured during discectomy from patients with back pain, sciatica, and radiologic evidence of disc herniation causing nerve root compression. OBJECTIVE: To investigate the claim of culpability of bacteria in causing the local inflammatory process seen in patients with disc herniation and radiculopathy. SUMMARY OF BACKGROUND DATA: Bacteria have been cultured from intervertebral discs of patients with sciatica. An infectious etiology for sciatica could have a dramatic effect on treatment options for this common problem. METHODS: To minimize the risk of contamination, the surgeon performed processing and culturing procedures intraoperatively under stringent sterile conditions. Immediately following disc excision, the specimens were divided into 4 pieces, and cultured in various aerobic and anaerobic culture mediums that were incubated for 2 weeks. RESULTS: The 120 specimens from 30 patients underwent bacterial culture growth: 116 were sterile, an 4 aerobic cultures (2 patients) grew coagulase-negative staphylococci, suggestive of contamination. CONCLUSIONS: These results refute the hypothesis that microbial infection plays a role in the pathogenesis of sciatica. It is possible that bacterial growth from discs reported in previous studies was at least partly related to contamination, which we painstakingly avoided by application of rigorous aseptic techniques.