(SS#II) The Predictive Potential of Nutritional and Metabolic Burden: Development of a Novel Validated Metric Predicting Increased Post-operative Complications in Adult Spinal Deformity Surgery

Introduction: Endocrine and metabolic disease burden has been previously identified to significantly influence patient outcomes, and may play a significant role in predicting increased peri and post-operative complications. Such effects have not been well studied in adult spinal deformity (ASD) surgery.

Methods: ASD patients ≥ 18 years with baseline (BL) and two-year (2Y) data were included. An internally cross-validated weighted equation using pre-operative laboratory and comorbidity data correlating to peri-operative complications was developed via backstep logistic regression. BMI and diabetes categorization was established per USA CDC and ADA guidelines, respectively. A novel spine surgery-specific metabolic burden score was calculated via Beta-Sullivan adjustment, and CIT determined threshold for ≥1 complication. Cohorts were ranked into halves for comparison (LOW vs HIGH).

Results: 201 ASD patients were included (mean age: 58.60±15.4, sex: 48% female, BMI: 29.95±14.31, CCI: 3.75± 2.40). Significant factors were: age (+1/year), hypertension (+18), peripheral vascular disease (+37), smoking status (+21), anemia (+1), VitD (+1 per ng/mL), hemoglobin (+1 per g/dL), BMI (+13/cat), and diabetes (+4/cat) correlating to occurrence of post-operative complications (model: p < .001). CIT determined scores above 175 correlated with ≥ 1 post-op complication (p < .001). Post-operatively, HIGH patients reported worse SF-36 Physical Functioning scores by 2Y (p=.042) than their LOW counterparts. Furthermore, HIGH patients reported higher rates of post-operative cardiac complications (p=.045) and were more likely to require reoperation (p=.024) compared to LOW patients.

Conclusion : Nutritional and metabolic related factors play a tremendous impact on the peri- and post-operative course of adult spinal deformity patients undergoing corrective surgery, speaking potentially to a diminished physiology reserve and resilience. Development of a validated novel nutritional and metabolic burden score demonstrated that patients with higher scores are at greater risk of increased post-operative complications and course. As such, surgeons should consider reduction of nutritional and metabolic burden pre-operatively to enhance outcomes and reduce complications in ASD patients.