Association between preoperative hypoalbuminemia and postoperative complications in spinal fusion surgery: an approach- and spinal level-stratified meta-analysis

While hypoalbuminemia is recognized as a risk factor for adverse postoperative outcomes in various surgeries, its specific impact on spinal fusion outcomes has not been systematically synthesized. This meta-analysis aimed to evaluate the association between preoperative hypoalbuminemia and postoperative complications in spinal fusion surgery, and to assess whether this effect differs across surgical approach and spinal region subgroups. A comprehensive search of PubMed, Embase, Web of Science, and Scopus was conducted, identifying 14 studies. Odds ratios (ORs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes were calculated as effect sizes using random-effects models. Subgroup analyses by spinal level and surgical approach were performed. The certainty of evidence for each outcome was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework adapted for prognostic-factor research. Hypoalbuminemia was significantly associated with an increased risk of wound complications (OR = 2.67, 95% CI 1.94–3.68), mortality (OR = 7.31, 95% CI 3.23–16.53), readmission (OR = 2.16, 95% CI 1.60–2.92), pulmonary complications (OR = 3.36, 95% CI 2.31–4.89), sepsis (OR = 4.46, 95% CI 2.46–8.12), blood transfusion (OR = 2.20, 95% CI 1.39–3.49), urinary tract infections (OR = 2.71, 95% CI 2.18–3.39), deep vein thrombosis (OR = 2.91, 95% CI 1.27–6.67), venous thromboembolism (OR = 2.46, 95% CI 1.30–4.66), and reoperation (OR = 1.89, 95% CI 1.10–3.22). No significant associations were found with renal, gastrointestinal, central nervous system, cardiac complications, or length of stay. The certainty of evidence for the primary outcomes, including mortality and wound complications, was moderate. Exploratory subgroup analyses suggested stronger associations for cardiac complications and blood transfusion in cervical fusion procedures, with statistically significant between-subgroup differences. Lumbar fusion showed numerically higher estimates for wound complications, although the subgroup difference was not statistically significant. These findings should be interpreted cautiously because most between-subgroup comparisons did not reach statistical significance and subgroup analyses were based on a limited number of studies. Preoperative hypoalbuminemia was significantly associated with an increased risk of postoperative complications following spinal fusion surgery. The strength of these associations may vary by spinal region, suggesting the potential value of region-specific risk stratification. Trial registration : This systematic review and meta-analysis was registered in PROSPERO with registration number CRD420261300508.