Adjunct pelvic fixation in short-to-medium segment degenerative fusion constructs independently predicts readmission and morbidity

CONTEXT: Despite increasing utilization of fusion to treat degenerative pathology, few studies have evaluated outcomes with pelvic fixation (PF). This is the first large-scale database study to compare multilevel fusion with and without PF for degenerative lumbar disease. AIM: The aim of this study was to compare the 30-day outcomes of multilevel lumbar fusion with and without PF. SETTINGS AND DESIGN: This was a retrospective cohort study. SUBJECTS AND METHODS: Lumbar fusion patients were identified using the National Surgical Quality Improvement Program database. Regression was utilized to analyze readmission, reoperation, morbidity, and specific complications and to evaluate for predictors thereof. STATISTICAL ANALYSIS USED: Student's t-test was used for continuous variables and Chi-squared or Fisher's exact test was used for categorical variables. Variables significant in the univariate analyses (P < 0.05) and PF were then evaluated for significance as independent predictors and control variables in a series of multivariate logistic regression analyses of primary outcomes. RESULTS: We identified 38,413 patients. PF predicted 30-day readmission and morbidity. PF was associated with greater reoperation in univariate analysis, but not in multivariate analyses. PF predicted deep wound infections, organ-space infections, pulmonary complications, urinary tract infection, transfusion, deep venous thrombosis, and sepsis. PF was also associated with a longer hospital stay. Age, obesity, steroids, and American Society of Anesthesiologists (ASA) class ≥ 3 predicted readmission. Obesity, steroids, bleeding disorder, preoperative transfusion, ASA class ≥3, and levels fused predicted reoperation. Age, African American race, decreased hematocrit, obesity, hypertension, dyspnea, steroids, bleeding disorder, ASA class ≥3, levels fused, and interbody levels fused predicted morbidity. Male gender and inclusion of anterior lumbar interbody fusion (ALIF) were protective of reoperation. Hispanic ethnicity, ALIF, and computer-assisted surgery (CAS) were protective of morbidity. CONCLUSIONS: Adjunctive PF was associated with a 1.5-times and 2.7-times increased odds of readmission and morbidity, respectively. ASA class and specific comorbidities predicted poorer outcomes, while ALIF and CAS were protective. These findings can guide surgical solutions given specific patient factors.