Medical Student Carle Illinois College of Medicine, Minnesota, United States
Introduction: We aim to investigate the effects of body mass index (BMI) on postsurgical cervical spine surgery outcomes and identify a potential substratification of obesity with worse outcomes.
Methods: The cervical spine Quality Outcomes Database (QOD) was queried for a total of 10,381 patients who underwent single-stage cervical surgery. Patients were substratified into six groups including underweight, (BMI less than 18), normal (BMI 20-25), overweight (BMI 25-30), class I Obesity (BMI 30-35), class II Obesity (BMI 35-40), and class III Obesity (BMI>40). Patient-reported outcomes for each cohort included mJOA, NRS-AP, NRS-NP, NDI, and EQ-5D. Univariate analysis was performed for 3- and 12-month follow-ups after surgical intervention.
Results: Obese patients requiring spine surgery were statistically younger than nonobese patients and had higher rates of diabetes compared to normal BMI patients. Class III obese patients had longer hospitalizations (p=0.02), greater blood loss, and longer surgical timing (p < 0.001). Surgical length was found to be longer for overweight and all obese patients (p < 0.01). Class III obese patients had higher odds of postoperative complications. Underweight patients had a higher rate of readmission at 3 months. Baseline PROs for patients with class II and III obesity were significantly worse than normal BMI patients (p < 0.05). Patients with class II and III obesity had lower odds at achieving optimal mJOA at 3-months (OR = 0.8 (0.67-0.94), p< 0.01, OR = 0.68 (0.56-0.82), p< 0.001, respectively) and 12-months (OR = 0.82 (0.68-0.98), p=0.03, OR = 0.79 (0.64-0.98), p=0.03, respectively). At 3-month follow-up, class III obese patients had lower odds of achieving MCID (OR = 0.75 (0.60-0.93), p = 0.01).
Conclusion : This study investigates the relationship between substratified BMI and postoperative outcomes of cervical spine surgery. Class II and III obese patients have substantially greater risk factors and poor outcomes postoperatively. Additionally, low BMI also presents unique challenges for patients.
