Impact of Spinal Instrumentation on Early Postoperative Inflammatory Markers: A Comparative Analysis in the Same Patient Cohort with or without Instrumentation.

Backgrounds: Postoperative inflammatory parameters are important markers of surgical site infection. Some authors have reported that spine surgery with instrumentation elevates CRP levels more than that without instrumentation does. However, those studies compared early postoperative inflammatory markers with or without instrumentation in different patients, although CRP levels vary widely among patients. Therefore, we investigated the impact of early postoperative inflammatory reaction with or without instrumentation in the same patients.

Methods: Data were examined for 72 patients who had undergone lumbar surgery twice, once with instrumentation and once without instrumentation. CRP level, white blood cell (WBC) count, and neutrophil count (NC) were measured before surgery and at 1, 3, 7, and 14 days after surgery. All surgery with instrumentation were PLIF and all without instrumentation were laminotomy.

Results: Comparison of peak CRP between procedures with instrumentation and those without instrumentation showed a consistent peak on day 3 for all patients across both types of surgical procedures. After PLIF, there was a significantly elevated CRP, WBC, and NC in comparison to these for laminotomy. There were significant interactions between time and PLIF in relation to CRP, WBC, and NC levels. There were significant interactions between time and number of levels (N-level) in relation to CRP and NC. Age, gender, blood loss, and duration of surgery did not influence the observed elevations of all markers.

Conclusions: Early postoperative trends were significantly higher after PLIF than after laminotomy for all three indices, with a significant interaction between time and N-level for CRP and NC.