The Age of Definitive Fusion Surgery for Early Onset Scoliosis Has Remained Constant Over the Past 2 Decades

Treatment options for early-onset scoliosis (EOS) are confounded by the risks associated with intervention at a younger age. Spinal instrumentation must be considered carefully due to potentially adverse effects to the spine, chest wall, and lungs. Posterior spinal fusion before subsequent growth can also lead to the crankshaft phenomenon. With the recent increasing interest in delaying spinal fusion, we aim to determine trends in patient age selection at a single definitive (termed "one and done") fusion for EOS.

We identified 791 patients from 2005 to 2022 who met the inclusion criteria (age 5 y or younger, single definitive fusion, and complete data). Patients who underwent a hemivertebrae resection with limited fusion were not included. Multiple linear regression was performed with date of fusion as the independent variable and age at definitive fusion as the dependent variable. Our regression included race and sex to control for their effects as confounders. We repeated this analysis with groups separated by scoliosis etiology and sex. Coefficients with P <0.05 were considered significant.

In the entire cohort, there was no significant change in the age at definitive fusion between 2005 and 2022 (coefficient=0.042, P =0.099). The mean age at fusion was 12.1 years. Of these, 167 (21.1%) cases had congenital scoliosis, 277 (35.0%) had idiopathic scoliosis, 191 (24.1%) had neuromuscular scoliosis, and 156 (19.7%) had syndromic scoliosis. Patients with idiopathic (-0.002, P =0.962), syndromic (-0.027, P =0.671), and neuromuscular (-0.005, P =0.924) EOS showed no significant change in the age at fusion. However, children with congenital EOS (0.171, P =0.006) and females (0.082, P =0.003) demonstrated a significant increase. On the basis of our regression models, the predicted age at definitive fusion increased from 10.6 years to 12.3 years in those with congenital EOS and from 11.4 to 12.1 years in females.

Over a 17-year study period, females and congenital EOS patients demonstrated significant increases in age at the time of definite fusion. There was no significant change for children with neuromuscular, idiopathic, or syndromic EOS over the same time frame. Further study is necessary to determine the nature of these disparities.