Can distraction-based surgeries achieve minimum 18 cm thoracic height for patients with early onset scoliosis?

Purpose: Karol et al. introduced the concept that 18 cm thoracic height is the critical point where a patient with early onset scoliosis (EOS) can maintain adequate pulmonary function. Our purpose was to determine if distraction-based surgeries will increase thoracic spine height to at least 18 cm in patients with EOS. Methods: Patients with EOS treated with distraction-based systems (minimum 5 years follow up, minimum five lengthenings). Radiographic analysis of thoracic spine height (T1–T12) at the last lengthening procedure. Results: One hundred and fifty-three patients (67 congenital, 21 neuromuscular, 38 syndromic, 27 idiopathic) with pre-operative mean age 4.6 years, scoliosis 75°, kyphosis 47° were evaluated. Their mean age at final lengthening procedure was 11 years (6–16), average number of lengthening procedures was 10.5 (4–21), mean final scoliosis was 53°, and mean final kyphosis was 58°. Final thoracic height was > 18 cm in 65% and was > 22 cm in 31% of patients. Based on etiology, only 48% of the congenital patients reached 18 cm compared to 81% neuromuscular, 84% syndromic and 67% idiopathic. This height gain was closely related to the percentage of scoliosis correction achieved for each etiology. Comparing congenital etiology to other etiologies, there was a lower percentage of patients in the congenital group that passed the 18 cm threshold (48% vs. 78%) (p < 0.05). Conclusion: At minimum 5 years follow up, distraction-based surgeries increased thoracic height for patients with EOS to greater than 18 cm in 65% of patients; however, only 48% of congenital patients reached this thoracic height threshold. Design: Retrospective review of prospectively collected registry data. LOI III.