The Impact of Obesity on Fusion Rate Following Anterior Cervical Discectomy and Fusion: A Population-Based Study

Obesity is associated with various comorbidities and increased risk for postoperative complications in spinal fusion surgery. However, data on the impact of obesity specifically on fusion rates after anterior cervical discectomy and fusion (ACDF) remains limited. This study aimed to evaluate the association of obesity with pseudarthrosis and revision surgery among patients undergoing ACDF.

This retrospective cohort study is conducted using the TriNetX global research network. Adult patients undergoing single or multilevel ACDF were identified. Patients were categorized into obese (body mass index [BMI] ≥ 30 kg/m²) and non-obese (BMI < 30 kg/m²) cohorts. The incidence of pseudarthrosis and revision surgery were assessed at 6-month, 1-year, and 2-year postoperative intervals. Propensity score matching (PSM) was used to balance baseline characteristics. Odds ratios (ORs) for outcomes were calculated.

Before matching, 38,377 obese and 35,071 non-obese patients were identified. After PSM, there were 21,467 patients in each cohort. The incidence of pseudarthrosis was consistently lower in the obese group. At 6-month, pseudarthrosis occurred in 12.5% of the obese group versus 13.6% in the non-obese group (OR: 0.91, 95% CI: 0.859-0.961). This trend continued at 1 year (13.5% vs. 14.6%, OR: 0.91, 95% CI: 0.861-0.961) and 2 years (14.5% vs. 15.7%, OR: 0.90, 95% CI: 0.861-0.957). Similar findings were found in the rate of revision surgery, where the obese patients showed lower incidence.

This study suggests that obesity is not associated with an increased incidence of pseudarthrosis and revision surgery after ACDF.