Effect of Obesity on Radiographic Alignment and Short-Term Complications After Surgical Treatment of Adult Cervical Deformity

Objective: We investigated the 30-day complication incidence and 1-year radiographic correction in obese patients undergoing surgical treatment of cervical deformity. Methods: The patients were stratified according to World Health Organization's definition for obesity: obese, patients with a body mass index of ≥30 kg/m²; and nonobese, patients with a body mass index of <30 kg/m². The patients had undergone surgery for the treatment of cervical deformity. The patient baseline demographic, comorbidity, and radiographic data were compared between the 2 groups at baseline and 1 year postoperatively. The 30-day complication incidence was stratified according to complication severity (any, major, or minor), and type (cardiopulmonary, dysphagia, infection, neurological, and operative). Binary logistic regression models were used to assess the effect of obesity on developing those complications, with adjustment for patient age and levels fused. Results: A total of 124 patients were included, 53 obese and 71 nonobese patients. The 2 groups had a similar T1 slope minus cervical lordosis (obese, 37.2° vs. nonobese, 36.9°; P = 0.932) and a similar C2–C7 (−5.9° vs. −7.3°; P = 0.718) and C2–C7 (50.1 mm vs. 44.1 mm; P = 0.184) sagittal vertical axis. At the 1-year follow-up examination, the T1 pelvic angle (1.0° vs. −3.1°; P = 0.021) and C2–S1 sagittal vertical axis (−5.9 mm vs. −35.0 mm; P = 0.036) were different, and the T1 spinopelvic inclination (−1.0° vs. −2.9°; P = 0.123) was similar. The obese patients had a greater risk of overall short-term complications (odds ratio, 2.5; 95% confidence interval, 1.1–6.1) and infectious complications (odds ratio, 5.0; 95% confidence interval, 1.0–25.6). Conclusions: Obese patients had a 5 times greater odds of developing infections after surgery for adult cervical deformity. Obese patients also showed significantly greater pelvic anteversion after cervical correction.