An Analysis of Implant Retention and Antibiotic Suppression in Instrumented Spine Infections: A Preliminary Data Set of 67 Patients

Background It is unclear whether patients can be taken off suppressive antibiotics with infected retained instrumentation. This study aimed to retrospectively analyze the perioperative course and antibiotic regimen that led to the clinical intervention of patients with infected spinal instrumentation.

Methods Consecutive adult patients with spine instrumentation who suffered surgical site infections (SSI) requiring debridement were retrospectively analyzed. The patients were grouped into 4 cohorts based on their clinical intervention: removal of instrumentation, reinstrumentation, retention of instrumentation with continued antibiotic suppression, and retention of instrumentation with no antibiotic suppression. Patient factors, infection factors, debridement, and antibiosis were compared.

Results Of the 67 patients with SSI after spine surgery and instrumentation, 19 (28%) had their instrumentation removed, 6 (9%) had their instrumentation exchanged, 25 (37%) had their instrumentation retained and were on antibiotic suppression, and 17 (25%) had their instrumentation retained without any suppression. Those who had their instrumentation removed had a later presentation of their infection averaging 85 days (range 6–280 days) postoperatively. There was an earlier presentation for those who retained their implants, with suppression averaging 19 days (range 9–39) and no suppression averaging 29 days (range 6–90 days) post operatively (P < .001).

Conclusions None of the patients with retained instrumentation without suppression had recurrence of infections after long-term follow-up. Lifelong antibiotic suppression may not be required with SSI that present early after early aggressive debridement. Patients with infections detected later are difficult to treat without removal of their original instrumentation.

Clinical Relevance This study presents the outcomes of surgical and antibiotic factors in patients with infected spinal instrumentation.