STUDY DESIGN: Retrospective analysis. OBJECTIVE: The objective of this study was to evaluate the efficacy of a surgical site infection (SSI) prevention protocol instituted in the Orthopaedic Spine Department at our institution. SUMMARY OF BACKGROUND DATA: SSI is an undesired complication of orthopedic spine surgical procedures. It poses a significant risk to the patient, as well as a financial toll on the health care system. A wide range of prophylactic measures have been used to attempt to reduce SSI rates. METHODS: A protocol consisting of a combination of 0.3% Betadine wound irrigation and 1 g of intrawound Vancomycin powder application was developed at our institution. Multiple data sources were consolidated for thorough evaluation of changes in SSI rates, patient risk factors, and changes in bacteriology. Identification of risk factors that predispose patients to SSI was performed using mixed-effects logistic regression in a univariate fashion. Risk factors with P values of 0.05 or less in univariate analysis were included together in a multivariate mixed-effects logistic regression model. RESULTS: SSI rates were reduced by 50% after the intervention; χ analysis comparing the SSI rates between the pre- and postintervention periods yielded a P value of 0.042. Rates of methicillin-resistant Staphylococcus aureus dropped from 30% to 7% and the rates of multibacterial infections dropped from 37% to 27%. The risk factors that were statistically significant in multivariate analysis were the following: age (odds ratio [OR] = 0.93), anemia (OR = 30.73), prior operation (OR = 27.45), and vertebral fracture (OR = 22.22). CONCLUSION: The combination of Betadine wound irrigation and intrawound vancomycin powder application led to both a clinically and statistically significant decrease in SSI rates by 50%. Bacteriology analysis and risk factor assessment proved to be valuable tools in assessing the efficacy of a new prophylactic measure and in the planning of future protocols. LEVEL OF EVIDENCE: 4.

Background

Surgical site infection is a morbid, devastating complication after spinal procedures. Studies have investigated the effect of wound lavage with 3.5% Povidone-iodine solution or the use of intrawound Vancomycin powder. We examined the effect of Povidone-iodine irrigation, intrawound Vancomycin powder, or a combination of both agents in a tertiary care Pediatric Hospital.

Methods

We queried our health system database for patients undergoing spinal surgery over an eight-year span between January 2008 and June 2016 and identified patient cohorts who received no intervention, intrawound Vancomycin alone, Povidone-iodine irrigation alone, or a combination of both agents. Infection rates were determined. The effect of treatment on outcome was analyzed using a logistic regression model.

Results

475 patients were identified who met study inclusion criteria. 88 non-neuromuscular patients received no intra-operative agent. The surgical site infection (SSI) rate in this group of patients was 10%. For the 194 non-neuromuscular scoliosis patients who received Povidone-iodine and Vancomycin powder, the infection rate was reduced to 0.7%. The SSI rate in the 180 non-neuromuscular patients who were treated with Vancomycin powder alone was 1.4%. 13 patients were treated with Povidone-iodine lavage only, with a small sample size precluding statistical comparison. Infection rate in the 132 neuromuscular disease patients decreased from 14 to 7% overall during this time span: while the odds ratio of infection was reduced in all neuromuscular treatment groups receiving intra-operative measures, statistical significance was not reached in any neuromuscular group studied.

Conclusions

A protocol using combined 3.5% weight/volume Povidone-iodine and Vancomycin powder was associated with the lowest infection rate in our non-neuromuscular patient population and should be considered as a low cost intervention in pediatric patients undergoing spinal deformity procedures.

Level of evidence

Level II.