Objective: The aim of this study was to examine the results of microbiological cultures from local bone autografts used in posterior lumbar interbody fusion (PLIF) and to identify their association with postoperative spinal infection.
Methods: The authors retrospectively evaluated cases involving 328 patients who had no previous spinal surgeries and underwent PLIF for degenerative diseases with a minimum 1-year follow-up. Local bone was obtained during laminectomy, and microbiological culture was performed immediately prior to bone grafting. The associations between culture results from local bone autografts and postoperative spinal infections were evaluated.
Results: The contamination rate of local bone was 4.3% (14 of 328 cases). Coagulase-negative Staphylococcus (29%) was the most common contaminant isolated, followed by Streptococcus species and methicillin-sensitive Staphylococcus aureus. Of 14 patients with positive culture results, 5 (35.7%) had postoperative spinal infections and were treated with intravenous antibiotics for a minimum of 4 weeks. One of these 5 patients also underwent reoperation for debridement during this 4-week period. Regardless of the microbiological culture results, the infection rate after PLIF with local bone autograft was 2.4% (8 of 328 cases), with 5 (62.5%) of 8 patients showing positive results on autograft culture.
Conclusions: The incidence of contamination of local bone autograft during PLIF was considerable, and positive culture results were significantly associated with postoperative spinal infection. Special attention focused on the preparation of local bone for autograft and its microbiological culture will be helpful for the control of postoperative spinal infection.
Keywords: CRP = C-reactive protein; ESR = erythrocyte sedimentation rate; PLIF = posterior lumbar interbody fusion; contamination; infection; local bone autograft; posterior lumbar interbody fusion.