Lightning Podiums: Cervical Degenerative - Room 802A

Presented by: E. Hoffman

Author(s):

A. Bandutia(1), L. Bivona(1), A. Nash(1), I. Bussey(1), K. Banagan(1), E. Koh(1), D. Gelb(1), S. Ludwig(1), E. Hoffman(1)

(1) University of Maryland, Baltimore, MD, United States

Abstract

Introduction: Recent literature has suggested that low virulence microorganisms may contribute to the progressive destruction of intervertebral discs, resulting in nerve impingement and mechanical pain. The topic remains controversial, however, with others claiming that the high rates of culture positive disc space infection are due to contamination. This study was undertaken to measure the rate of positive cultures from disc tissue harvested from patients undergoing routine anterior cervical decompression and fusion.

Material and Methods: After IRB approval, a series of consecutive patients undergoing elective anterior cervical discectomy and fusion (ACDF) for degenerative disc disease were enrolled in the study. During anterior exposure and prior to discectomy, a sample of the longus colli was obtained, as a control, with an unused, sterile instrument, and sent for culture. Using fresh instruments, disc tissue samples were also sent for culture. Each patient received prophylactic antibiotics prior to the procedure. Each tissue sample was homogenized, gram stained, and cultured using sterile technique. Aerobic and anaerobic cultures were obtained and were kept for 5 and 14 days, respectively.

Results: 37 patients (mean age 52.62 years, 38% male) were enrolled in the study. Overall, 51.4% (19 of 37, 28 disc specimens) had at least one positive disc culture, Propionibacterium acnes (P. acnes) accounting for 84.2% of the positive samples (16/19 pts, 28/65 discs). Other bacteria identified in positive cultures included Staphylococcus (6/37, 16.2%) and Streptococcus (3/37, 8.1%). Tissue from the longus colli was positive in 17/37 patients (46.0%), 14 of these had at least one positive disc culture (82.4%). P. acnes was culture positive in 9/17 positive controls (52.9%). Fisher's exact test of independence between patient's with a positive disc culture and patients with a positive control revealed a p value of 0.0081, indicating a correlative relationship between these factors. In addition, we were unable to find any significant correlation between positive disc cultures and age, gender, BMI, and previous cervical spine surgery.

Conclusion: Although there was a high rate of culture positive disc samples, based on the associated high rate of culture positivity in our control group, it appears that culture positive discs may be due to contamination.