Is Obesity in Adolescent Idiopathic Scoliosis Associated With Larger Curves and Worse Surgical Outcomes?

STUDY DESIGN: A multicenter retrospective study of preoperative characteristics and surgical outcomes in adolescent idiopathic scoliosis (AIS). OBJECTIVE: To determine the effect of obesity on (i) curve magnitude at first presentation to an orthopedic surgeon, and (ii) surgical outcomes. SUMMARY OF BACKGROUND DATA: Clinical findings for scoliosis may be less apparent in overweight adolescents. The effect of obesity on curve magnitude at presentation to an orthopedic surgeon has not been studied. It is unclear whether obesity is associated with worse surgical outcomes in AIS. METHODS: Demographic, radiographic, perioperative, and complications data were collected on AIS patients who had undergone posterior spinal fusion (PSF). Descriptive and inferential analyses were conducted to compare healthy-weight (HW) [body mass index percentile for age (BMI%) ≤ 84], overweight (OW; BMI% ≥ 85), and obese (OB; BMI% ≥ 95) adolescents. RESULTS: We analyzed 588 patients (454 HW, 134 OW, and 71 OB). In comparison with the HW adolescents, major curve magnitude at presentation to orthopedics was larger in the OW adolescents (49.3° vs. 43.9°) (P < 0.0001) and OB adolescents (50.4° vs. 43.9°) (P = 0.001). The OW and OB groups had increased preoperative major curve magnitude [(59.1° vs. 55.4°) (P = 0.001); (59.9° vs. 55.4°) (P = 0.001)], preoperative minor curve magnitude [(42.2° vs. 37.2°) (P < 0.0001); (43.0° vs. 37.2°) (P = 0.001)], preoperative thoracic kyphosis [(30.8° vs. 25.7°) (P < 0.0001); (33.7° vs. 25.7°) (P < 0.0001)], and surgical time [(307 vs. 276 mins) (P = 0.009); (320 vs. 276 mins) (P = 0.005)] than the HW group.Subgroup analysis of the patients with a minimum 2-year follow-up (n = 245) showed a trend towards a higher complication rate in the OB group (47.8% vs. 28.3%) (P = 0.054). The OB group had significantly more superficial infections than the HW group (13.0% vs. 1.6%) (P = 0.001). CONCLUSION: OW patients with AIS have a larger curve magnitude at presentation to an orthopedic surgeon. OW patients who undergo PSF for AIS have increased surgical times. OB patients may be at higher risk of postoperative complications. LEVEL OF EVIDENCE: 3.