I appreciate the comments on our article "Local vancomycin therapy to reduce surgical site infection in adult spine surgery: a randomized prospective study"[1]. I would like to clarify and add some comments.

The purpose of this RCT is to investigate the effect of local vancomycin on postoperative infection. Our intention in this study was not to determine the risk factors or check them in the cases, and as it is specified in table 1, the risk factors mentioned in the literature (such as diabetes, IHD, COPD, smoking, and dural tear) [2, 3] were determined in the cases so that their distribution in the two groups does not differ and does not affect the results.

In our study, spine surgery was performed in one center by two experienced neurosurgeons. Based on statistical analysis, there was no significant difference in the number of vancomycin and control cases in two groups.

Dural tear can be a risk factor for postoperative infection [4]. In our study as shown in table 1, distribution of CSF leak cases (traumatic or iatrogenic) has no statistically significant difference in the vancomycin and control groups. In this study, 23 cases of CSF leak were reported, of which 6 cases were traumatic and 17 cases were iatrogenic, and all cases were repaired as far as possible during the operation. Among the cases of CSF leak, there was one case of superficial infection and one case of deep infection, the latter of which underwent reoperation.

There is doubt about the effect of negative suction drainage after spinal surgery [5]. We kept the negative suction drain for 24 h after the surgery, and if the drainage was high, the drain was kept under vacuum conditions for a maximum of 48 h, except for 8 cases of CSF leak that there was CSF in drain, in which the drain was kept for the second 24 h without vacuum.

In our study, there were ten cases of infection in the instrument group, and the average level in them was 3.4.

In the present study, all elective patients had a bath and trauma cases did not have a bath due to the possibility of spinal instability, accompanying injuries and short time before the surgery.