388. Spinal Implant Infections Treated with Debridement and Hardware Retention

Background Surgical site infections following spinal surgery affect 0. 3 to 20% of patients. The longer the infection, the greater the chance of antibiotic treatment failure due to the establishment of mature microbial biofilm on the hardware, requiring its removal for infection eradication. Methods Retrospective cohort of patients with microbiologically confirmed SII following spinal surgery treated with debridement and retention. SII was defined as the presence of clinical signs of deep surgical site infection with 2 or more positive culture results of tissue surrounding the implant taken during surgical debridement; or from CT guided biopsy. Inclusion criteria: adults with a 1º episode of microbiological confirmed SII diagnosed from 2008 to 2017 with >2 years of follow-up, treated with implant retention. Definitions Early-onset infection (EOI): infection 1 year of implant placement. Statistical analysis made in Graph Pad Prism 5. 0. Results We analyzed 19 patients with SII treated with hardware retention. Mean age was 54 (21–70) years, 63% were female. Comorbidities, clinical manifestations and motive for surgery are in Table 1 and Figure 1. Hardware material used was titanium 15(79%) and steel 4(21%). In addition to the hardware,11 patients (57. 9%) underwent bone grafting, 4 experienced treatment failure (4/11 = 36. 4%); 2 patients had nonmetallic material inserted (carbon polymer), the 2 patients experienced failure. 16 patients (84. 2%) had EOI, 2 (10. 5%) LOI, 1 (5. 3%) DOI. Failure requiring implant removal was observed in 26. 3% (n = 5), 2 of the cases were EOI, 2 LOI and 1 DOI. Bacterial characteristics of patients are shown in Table 2. 47,4% of patients required more than one debridement (Figure 2). In the lineal regression model, treatment failure was associated with bone grafting (P = 0. 04) and the use of carbon polymer materials (P = 0. 007). Conclusion Treatment of SII with debridement plus antimicrobials treatment is acceptable, with a rate failure of 26%. In LOI and DOI spinal implant retention is more prone to fail. Bone grafting and the presence of polymers seem to be associated with treatment failure of conservative strategies. Disclosures All authors: No reported disclosures.