Malnutrition and adverse outcomes after spine surgery: a systematic review and meta-analysis.

Abstract

BACKGROUND CONTEXT: Malnutrition is linked to adverse surgical outcomes, but its impact in spine surgery remains unclear due to inconsistent findings and heterogeneous definitions, including use of serum albumin, prealbumin, lymphocyte count, the Geriatric Nutritional Risk Index, and the Prognostic Nutritional Index. We conducted a systematic review and meta-analysis to evaluate the relationship between malnutrition and postoperative outcomes in spine surgery. PURPOSE: To systematically evaluate the association between preoperative malnutrition and postoperative outcomes in patients undergoing spine surgery. STUDY DESIGN: Systematic review and meta-analysis. PATIENT SAMPLE: Patients undergoing elective or urgent spine surgery across included observational studies comparing malnourished vs well-nourished cohorts. OUTCOME MEASURES: Primary outcomes included postoperative mortality and overall surgical complications. Secondary outcomes included infectious complications (sepsis, urinary tract infection, wound complications), delirium, reoperation, 30-day and 90-day readmission, and prolonged length of hospital stay. METHODS: A systematic search of PubMed, Embase, Cochrane Library, and Web of Science was performed on April 7, 2025, following PRISMA guidelines. Studies directly comparing postoperative outcomes in malnourished vs well-nourished spine surgery patients were included. A random-effects model generated pooled odds ratios for complications. Outcomes assessed included mortality, surgical complications, infectious outcomes, readmission, reoperation, delirium, prolonged length of stay, and wound complications. RESULTS: Of 2,851 screened articles, 37 met the inclusion criteria, encompassing 16,987 malnourished patients. Malnutrition was associated with significantly increased odds of mortality (OR: 4.05, 95% CI [2.97-5.54]), delirium (OR: 3.95, 95% CI [2.49-6.27]), sepsis (OR: 2.77, 95% CI [2.31-3.33]), surgical complications (OR: 1.79, 95% CI [1.57-2.04]), urinary tract infection (OR: 1.81, 95% CI [1.59-2.06), wound complications (OR: 2.10, 95% CI [1.80-2.45]), reoperation (OR: 1.70, 95% CI [1.46-1.97]), prolonged length of hospital stay (OR: 3.46, 95% CI [2.57-4.65]), 30-day readmission (OR: 1.59, 95% CI [1.36-1.86]), and 90-day readmission (OR: 2.13, 95% CI [1.67-2.71]). CONCLUSIONS: Malnutrition was consistently associated with adverse outcomes after spine surgery. Routine nutritional assessment and targeted preoperative optimization should be considered a standard component of perioperative spine care to help reduce postoperative complications and improve recovery.