title: Do Thoracolumbar/lumbar Curves Respond Differently to Growing Rod Surgery Compared With Thoracic Curves?
abstract: METHODS
  Retrospective study.
  
  
  OBJECTIVE
  To compare radiographic outcomes between primary thoracic and primary thoracolumbar/lumbar curves in patients with early-onset scoliosis (EOS) after growing rod (GR) surgery.
  
  
  BACKGROUND
  Previous studies have shown the efficacy of GR surgery for progressive EOS. However, there is no information on the behavior of different curve patterns in EOS after GR surgery.
  
  
  METHODS
  A multicenter international EOS database query identified 175 patients who met the following inclusion criteria: non-congenital etiology, GR surgery, ≤ 10 years of age at index surgery, minimum 2-year follow-up, and at least 3 lengthenings. Patients were categorized into 2 groups based on the Scoliosis Research Society definition of the anatomical location of primary curves: group 1 included thoracic apices (T2 to T11/12 disc) and group 2 included thoracolumbar (T12 to L1) and lumbar (L1/2 disc to L4) apices. Radiographic measurements were performed before and after index surgery and at latest follow-up.
  
  
  RESULTS
  A total of 139 patients (79%) had primary thoracic (group 1) and 36 (21%) had primary thoracolumbar or lumbar curves (group 2). Mean number of levels instrumented was statistically greater in group 2 (15.0) versus group 1 (13.6) (p < .05). Group 2 had statistically better mean curve correction than group 1 after the index GR surgery (51% and 44%, respectively; p < .05). However, there was no significant difference in mean percent curve correction at latest follow-up (46% and 39%, respectively; p > .05). Implant complication rate was 45% and 47% for groups 1 and 2, respectively. Preoperative curve flexibility was greater in group 2 (45%) compared with group 1 (40%) (p > .05).
  
  
  CONCLUSIONS
  Overall, thoracolumbar/lumbar and thoracic curves achieve similar major curve correction and have a similar complication profile.
authors.affiliation: San Diego Center for Spinal Disorders, 4130 La Jolla Village Drive, Suite 300, La Jolla, CA 92037, USA.
authors.forename: Navid R
authors.initials: NR
authors.lastname: Arandi
authors.affiliation: San Diego Center for Spinal Disorders, 4130 La Jolla Village Drive, Suite 300, La Jolla, CA 92037, USA.
authors.forename: Jeff B
authors.initials: JB
authors.lastname: Pawelek
authors.affiliation: San Diego Center for Spinal Disorders, 4130 La Jolla Village Drive, Suite 300, La Jolla, CA 92037, USA.
authors.forename: Nima
authors.initials: N
authors.lastname: Kabirian
authors.affiliation: Department of Orthopaedics, University Hospitals, Rainbow Babies and Children's Hospital, 11100 Euclid Ave, Cleveland, OH, 44106 USA.
authors.forename: George H
authors.initials: GH
authors.lastname: Thompson
authors.affiliation: Boston Children's Hospital, 300 Longwood Avenue, Boston, MA, 02115 USA.
authors.forename: John B
authors.initials: JB
authors.lastname: Emans
authors.affiliation: Children's Hospital of Philadelphia, 3400 Civic Center Blvd, Philadelphia, PA, 19104 USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Flynn
authors.affiliation: Children's Hospital of Philadelphia, 3400 Civic Center Blvd, Philadelphia, PA, 19104 USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Dormans
authors.affiliation: San Diego Center for Spinal Disorders, 4130 La Jolla Village Drive, Suite 300, La Jolla, CA 92037, USA; Department of Orthopedic Surgery, University of California, San Diego, CA, USA. Electronic address: akbarnia@ucsd.edu.
authors.forename: Behrooz A
authors.initials: BA
authors.lastname: Akbarnia
keywords: Early-onset scoliosis; Growing rods; Growth-friendly treatment; Pediatric spinal deformity