Ideal Surgical Age for Distraction-Based Growth Friendly Techniques to Minimize Complications

Distraction-based growth-friendly techniques are widely used in early-onset scoliosis (EOS). However, the optimal timing of index growing rod surgery remains controversial because of the risk of complications. Our aim was to determine the relationship between age at index surgery and complication frequency and severity, and predictors of cumulative complication burden in EOS patients treated with dual growing rods.

We retrospectively reviewed 95 patients with EOS treated with traditional growing rods (TGRs) and magnetically controlled growing rods (MCGRs) between 2004 and 2023. Mean age at index surgery was 6 years 10 months, and the mean follow-up duration was 5 years 10 months. All patients underwent at least 2 lengthening procedures with a minimum follow-up of 2 years. ROC analysis was performed to determine the optimal age cutoff for complication risk, and patients were stratified into younger (≤85 mo) and older (>85 mo) groups. Kaplan-Meier analysis was used to compare complication-free survival between groups, while multivariate Poisson regression identified predictors of total complication incidence.

The complication rate was significantly higher in the younger patients than in the older ones (89% vs. 61%, P=0.007). The incidence of severe complications (modified Clavien-Dindo-Sink grade ≥3a) did not differ between the groups. The Poisson regression demonstrated that younger age at index surgery and use of TGRs were independently associated with a higher complication incidence rate. When stratified by age, TGRs were associated with a higher complication rate than MCGRs in the older group (66% vs. 25%), whereas no difference was observed in the younger patients. An unplanned return to the operating room occurred in 35% of patients, with no age-related difference.

Younger age at index growing rod surgery is associated with a higher overall complication rate but not increased complication severity or reoperation risk. Younger age at index surgery and use of traditional growing rods were identified as independent predictors of increased complication burden and should be considered during treatment planning. Delaying index surgery to 85 months of age or later may help reduce complication burden in selected patients with EOS when curve progression and cardiopulmonary status permit.

Level III-retrospective comparative series.