LAUSR

OBJECTIVE The effect of malnutrition on outcomes following posterior lumbar fusion (PLF) remains understudied. This study analyzes the effect of malnutrition across a comprehensive range of BMI on complications following PLF. METHODS The Pearldiver Mariner database was queried between 2010-2020 using ICD-9 and ICD-10 codes for malnutrition and CPT codes for PLF. Patients were identified with preoperative BMI diagnosis codes and partitioned into one of the following BMI cohorts: underweight (BMI <20), normal BMI (19-30), obese (BMI 30-40), and morbidly obese (BMI>40). An additional all-BMI cohort was created using patients with any BMI code. All cohorts were matched 1:3 to control patients within the same BMI group without malnutrition based on age, gender, and Charlson Comorbidity Index (CCI). Complication rates were calculated using the Pearson Chi-square method with statistical significance set to p < 0.05. RESULTS The number of patients in each cohort were: 1,106 (all-BMI), 227 (underweight), 808 (normal), 667 (obese), and 449 (morbidly obese). Statistical analysis showed the all-BMI cohort had greater odds of complications related to instrumentation (Odds Ratio [OR]; 2.28; p < 0.001), need for revision (OR: 2.04; p < 0.001), pulmonary (OR: 1.45; p < 0.001), sepsis (OR: 2.89; p < 0.001), surgical site (OR: 1.87; p < 0.001), and urinary (OR: 1.41; p < 0.001) (figure 1). No difference was noted between the BMI-specific cohorts for complication risk (figure 2). CONCLUSION Our analysis indicates that malnutrition may independently increase PLF complication risk. Surgeons may consider preoperative optimization for malnutrition patients to reduce complication risk.