Background: While obesity is on the rise in the pediatric population, there is a paucity of literature concerning the effect
obesity may have on post-operative outcomes. Posterior spinal fusion for the treatment of Adolescent Idiopathic Scoliosis is one
of the most common spinal procedures in the pediatric population. However, the role obesity may play on outcomes following this
extensive surgery is poorly understood.
Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database for
children was queried to identify pediatric patients who underwent spinal deformity correction surgery. Patients who had undergone
an anterior surgical approach were excluded from the analysis. Children were categorized as Obese if their BMI exceeded 95th
percentile for their age group in months. They were then stratified into cohorts based on their obesity status (Obese vs. Non-Obese)
and compared in regard to demographics, pre-operative comorbidities, intra-operative, and post-operative outcomes. Propensity
score matching was then performed to limit confounders between the two cohorts. Statistical analysis was performed utilizing
independent t-tests for continuous variables and chi-square analysis for categorical data. Statistical significance was set at <0.05.
Results: A total of 1702 patients met the inclusion criteria for the study, 851 obese and 851 non-obese. Pre-operatively, the
mean age of both the non-obese and obese patients was 14 years (p=0.481). The mean weight was 48.62 kg for non-obese patients,
and 83.06 for obese patients (p<0.001), while BMI was 20.46 in the non-obese group and 36.99 in the obese group (p<0.001).
Both cohorts had a majority of female patients (non-obese: 75.3% vs. obese: 74.6%, p=0.780). The most common ASA score in
both groups was 2 (non-obese: 71.0% vs. obese: 70.2%, p=0.899). White patients underwent fusion more often in the non-obese
and obese groups (71.7% vs. 70.9%, p=0.820). Intra-operative findings demonstrated obese patients spent a significantly longer
time in the operating room (272.75 minutes vs. 293.10 minutes, p<0.001). Non-obese patients had a significantly longer LOS than
obese patients (5.75 days vs. 4.59 days, p<0.001). There was a significantly higher incidence of superficial SSI in obese patients
(0.2% vs. 1.2%, p=0.038). Non-obese patients had significantly more bleeding needing transfusions than obese patients (67.0% vs.
61.6%, p=0.023), and had more total blood transfused (335.94 mL vs. 222.02 mL, p<0.001). Obese patients had a higher 30-day
readmission rate (2.6% vs. 5.2%, p=0.008). No other differences were observed in demographics, medical conditions, or postoperative
Conclusion: Obesity significantly increases the risk for early complications in pediatric patients undergoing spinal deformity
surgery. Obese patients are at increased risk for longer operative time, postoperative superficial infection and 30-day readmission.
As such, spine surgeons should be cognizant of these potential adverse outcomes and should consider the benefits of prophylactic
Abbreviations: AIS: Adolescent idiopathic scoliosis; BMI: Body Mass Index; SSI: Surgical Site Infection; ASA: American Society of
Anesthesiology; SSI: Surgical Site Infection; LOS: Length of Stay; UTI: Urinary Tract Infection; DVT: Deep Vein Thrombosis;