Associations between Body Mass and the Outcome of Surgery for Scoliosis in Chinese Adults

Background: In this study we intended to prove that being overweight has an unfavorable impact on the surgical treatment outcome of adult idiopathic scoliosis (AdIS). Methods: This is a retrospective study on the surgical treatment of seventy-one more than 30 years old (58 females and 13 males; mean age 42.9 +/- 12.2) idiopathic scoliotic patients with a minimum follow up of at least 2 years. The patients were divided into an overweight group (BMI >= 23) and a non-overweight group (BMI < 23). Preoperative, postoperative first erect and final follow-up radiographic measures, perioperative data, the Oswestry disability index (ODI), and the visual analog scale (VAS) were reviewed and compared. Findings: In the overweight group, no significant differences in radiographic measures, perioperative data, preoperative comorbidities, or postoperative complications, except for the more frequent concomitance of preoperative thoracic kyphosis 37.9 +/- 7.7 vs. 26.5 +/- 11.8 (P = 0.000) and thoracolumbar kyphosis 14.9 +/- 10.1 overweighted group vs. 6.5 +/- 9.9 non-overweighted group respectively (P = 0.002) were found. A higher morbidity of hypertension 36.8% vs. 9.6% (P = 0.004) was also observed in the overweight group. Postoperative ODI and VAS improved significantly in both groups compared to preoperative values. The postoperative ODI of the overweight group (19.6 +/- 12.4) was significantly higher than that of the non-overweight group (12.4 +/- 7.9) (P = 0.022). Conclusions: Overweight adult idiopathic scoliotic patients had more frequent concomitance of preoperative thoracic kyphosis and thoracolumbar kyphosis and more serious postoperative pain. However, BMI did not affect the outcomes of surgical correction for coronal and sagittal scoliotic deformity and their postoperative complication rates were not significantly affected.