Does an increased preoperative body mass index (BMI) affect adolescent idiopathic scoliosis surgery outcomes and complications? A meta-analysis.

OBJECTIVE

Adolescent idiopathic scoliosis (AIS) is the most common form of scoliosis. With obesity reaching unprecedented levels in adolescents, we aimed to perform a meta-analysis examining the impact of increased Body Mass Index (BMI) on AIS corrective surgery.

METHODS

Cochrane, PubMed, and Google Scholar (pages 1-20) were searched up to July 2024. The inclusion criteria consisted of studies comparing increased BMI patients with patients having a normal BMI (BMI < 25 OR < 85th percentile) in the setting of corrective surgery for AIS. Investigations consisting of non-comparative studies, or studies with non-relevant outcomes were excluded.

RESULTS

Twelve retrospective studies met inclusion criteria and were included in this meta-analysis. There were significantly fewer complications (OR = 0.44, p = 0.002), readmissions (OR = 0.39, p = 0.05), and wound-related complications (OR = 0.32, p = 0.005) in patients with normal BMI. In addition, the patients with normal BMI had a shorter operative time (MD = - 15.43, p = 0.005) as well as a smaller pre- and post-operative major curve (MD = - 1.54; p = 0.01, MD = - 2.45; p = 0.002) and thoracic kyphosis (MD = - 4.87; p < .001, MD = - 2.67; p < .001).

CONCLUSION

Patients undergoing AIS surgery with an increased preoperative BMI may be associated with less favorable outcomes. Although the elevated BMI alone may be the cause of the increased complications in some patients, obese patients also presented with larger curves and more kyphosis, thus potentially explaining an additional contributor to the increased complication rate. Curves may be less noticeable in obese patients as compared to normal weight patients, thus delayed diagnosis may be occurring. Optimized scoliosis screening in obese patients, and also studies assessing the benefits of preoperative weight management in AIS surgery are needed.