Association of malnutrition with surgical site infections following spinal surgeries: systematic review and meta-analysis

Abstract Background Surgical site infections (SSI) following spinal surgeries is a frequent clinical problem with significant clinical and socio-economic consequences. Malnutrition has been linked with these devastating complications in various other surgical procedures. Aim To investigate whether malnutrition is a risk factor for SSI following spinal surgeries. Methods We systematically searched MEDLINE and SCOPUS through May 2019, the Cochrane Library and proceedings of major international orthopedic congresses (2015–2018). Cohort and case-control studies assessing malnutrition as a risk factor for SSI in patients undergoing spinal procedures were considered eligible. Μalnutrition was defined according to laboratory measurements or by relevant ICD-9 codes. SSI was the outcome of interest. Two reviewers independently abstracted study data and assessed each study’s risk-of-bias. Pooled effect estimates were calculated using random-effects models. Findings A total of 22 studies (20 retrospective cohort and 2 case-control) with over 175,000 participants (of whom 2.14% developed postoperative SSI) were analyzed. SSI were more likely to develop in malnourished patients (OR=2.31, 95% CI: 1.75–3.05). While preoperative malnutrition was significantly associated with SSI in patients undergoing thoracolumbar spine and sacral surgeries, no significant difference was seen in cervical spine surgeries. In subgroup analyses, similar results were observed for both hospital-based (OR=3.16, 95% CI: 1.84–5.43) and population-based studies (OR=2.00, 95% CI: 1.63–2.46). Conclusions Malnutrition is associated with increased risk of developing SSI after spinal surgery. Further high-quality research is warranted to investigate whether improvement of preoperative nutritional status can decrease SSI rates.