Age at Initiation and Deformity Magnitude Influence Complication Rates of Surgical Treatment With Traditional Growing Rods in Early-Onset Scoliosis

Abstract

Study design: Multi-center retrospective review.

Objective: The purpose of this study was to identify preoperative variables associated with postoperative complications in early-onset scoliosis (EOS) patients treated with traditional growing rods (TGR); and to develop a model to predict the incidence of postoperative complications based on preoperative variables.

Summary of background data: TGRs are commonly used to treat progressive EOS. Prior research has demonstrated a high rate of postoperative complications using this technique; however, few studies have identified preoperative factors that contribute to such complications.

Methods: A total of 110 patients who initiated TGR treatment before 10 years of age and completed final treatment were identified from a multi-center database. Overall treatment effect was calculated for major curve size, thoracic kyphosis, thoracic height, and total spine height. Univariable and multivariable logistic regression identified preoperative predictors of complications. An algorithm was developed and validated to calculate the probability of complications based on preoperative data.

Results: All patients completed TGR treatment (average follow-up 8.1 years). The overall treatment effect was a significant decrease in major curve magnitude, increase in thoracic height, increase in spine height, and no significant change in thoracic kyphosis. There were 263 total complications in 87 patients (79%) resulting in 84 unplanned surgeries. The most common complications were implant-related (49%), surgical site infection (23%), medical (19%), alignment (6%), and neurologic (3%). The significant independent preoperative predictors of complications were age at implantation and preoperative thoracic kyphosis. Multivariable regression showed that age less than 7.6 years, thoracic kyphosis greater than 38 degrees, or major curve magnitude greater than 84 degrees significantly increased the probability of complications.

Conclusions: Earlier age at implantation, greater thoracic kyphosis, and larger major curves increased the probability of complications following TGR instrumentation. These findings provide a valuable tool for predicting complications that may aid in surgical planning and shared decision making with patients and their families.

Level of evidence: IV.

Keywords: Deformity magnitude; Early-onset scoliosis; Postoperative complications; Traditional growing rods.