• Eiichiro Iwata, Hideki Shigematsu, Yusuke Yamamoto, Masato Tanaka, Akinori Okuda, Yasuhiko Morimoto, Keisuke Masuda, Hiroshi Nakajima, Munehisa Koizumi, and Yasuhito Tanaka.
• Department of Orthopaedic Surgery, Nara Medical University, Nara, Japan.
• Spine. 2018 Sep 15; 43 (18): E1096-E1101.

Study DesignCase-control study.ObjectiveTo identify laboratory markers for surgical site infection (SSI) in posterior lumbar decompression surgery, which are not affected by operative factors, and to determine the diagnostic cutoffs of these markers.Summary Of Background DataNumerous laboratory markers are used for the early detection of SSI; however, these markers may be affected by operative factors.MethodsThe study included 182 participants. They were divided into an SSI group (patients who developed deep SSI; n = 8) and a no-SSI group (n = 174). We reviewed data on the C-reactive protein level and total white blood cell count and differential count before posterior lumbar decompression surgery and 1 and 4 days postoperatively. We determined which markers differed significantly between the groups and identified the markers that were not affected by operative factors (operative time, intraoperative blood loss, and number of operative segments) in the no-SSI group. We then determined the diagnostic cutoffs of these unaffected markers using receiver operating characteristic curves.ResultsWe identified the lymphocyte percentage at 4 days postoperatively (cutoff, <19.4%; sensitivity, 80.0%; specificity, 62.5%; area under the curve, 0.78) and lymphocyte count at 4 days postoperatively (cutoff, <1010/μL; sensitivity, 93.7%; specificity, 62.5%; area under the curve, 0.78) as reliable markers.ConclusionLymphocyte percentage and count at 4 days postoperatively are reliable markers for SSI after posterior lumbar decompression surgery. Lymphocyte count at 4 days postoperatively can be considered as a superior marker for screening because it has a high sensitivity and can be measured early.Level Of Evidence4.

29 keywords...

hide…