Timing of Antibiotic Prophylaxis for Preventing Surgical Site Infections in Foot and Ankle Surgery.

BACKGROUND: Surgical site infections (SSIs) are one of the most troublesome complications after foot and ankle surgery. Previous literature has emphasized the significance of appropriate timing of antibiotic prophylaxis. However, the optimal timing of antibiotic prophylaxis for SSI prevention is still inconclusive. Our study aimed to investigate the optimal timing of antibiotic administration and to elucidate the risk factors for SSIs in foot and ankle surgery.

METHODS: A retrospective review of 1933 foot and ankle procedures in 1632 patients from January 1, 2011, through August 31, 2015, was performed. Demographic data; type, amount, and timing of antibiotic administration; incision; and closure time were recorded. Subsequent wound infection and incision and drainage procedure (I&D) within 30 days and 90 days were documented. Outcomes and demographic variables were compared between procedures in which antibiotics were administered less than 15 minutes and between 15 to 60 minutes prior to incision. A total of 1569 procedures met inclusion criteria.

RESULTS: There were 17 cases (1.1%) of subsequent wound infection, of which 6 required a subsequent I&D within 30 days. There were 63 additional cases (4%) of wound complications, which did not meet SSI criteria. When comparing SSI and non-SSI groups, the only significant independent predictors were longer surgeries and nonambulatory surgeries (both P < .05). Stepwise multivariate logistic regression analysis demonstrated that 91.8% of the risk of an SSI could be predicted by ASA score and length of surgery alone.

CONCLUSION: In foot and ankle surgeries, the timing of intravenous antibiotic prophylaxis did not appear to play a significant role in the risk of SSI. Host factors and duration of surgery appear to have played a much larger role in SSI than the timing of antibiotic prophylaxis.

LEVEL OF EVIDENCE: Level III, retrospective comparative study.