Anterior Spinal Growth Tethering for Skeletally Immature Patients with Scoliosis

Abstract

Background: Anterior spinal growth tethering (ASGT) has been shown to alter spinal growth with the potential to correct scoliosis while maintaining spine flexibility. The purpose of this study was to report the 2 to 4-year outcomes of ASGT in skeletally immature patients with thoracic scoliosis. Methods: We conducted a retrospective review of patients with thoracic scoliosis who underwent ASGT with a minimum of 2 years of follow-up. Patient demographics, perioperative data, and radiographic outcomes are reported. A “successful” clinical outcome was defined as a residual curve of <35° and no posterior spinal fusion indicated or performed at latest follow-up. Results: Seventeen patients met the inclusion criteria. The etiology was idiopathic for 14 and syndromic for 3. The mean follow-up was 2.5 years (range, 2 to 4 years). Preoperatively, all patients were at Risser stage 0, with a mean age at surgery of 11 ± 2 years (range, 9 to 14 years). There was an average of 6.8 ± 0.5 vertebrae tethered per patient. The average thoracic curve magnitude was 52° ± 10° (range, 40° to 67°) preoperatively, 31° ± 10° immediately postoperatively, 24° ± 17° at 18 months postoperatively, and 27° ± 20° at latest follow-up (51% correction; range, 5% to 118%). Revision surgery was performed in 7 patients: 4 tether removals due to complete correction or overcorrection, 1 lumbar tether added, 1 tether replaced due to breakage, and 1 revised to a posterior spinal fusion. In 3 additional patients, posterior spinal fusion was indicated due to progression. Eight (47%) of the patients had a suspected broken tether. Ten (59%) of the 17 were considered clinically successful. Conclusions: Despite most patients having some remaining skeletal growth at the time of review, the results of the current study demonstrate that at mid-term follow-up, ASGT showed a powerful, but variable, ability to modulate spinal growth and did so with little perioperative and early postoperative risk. Fusion was avoided for 13 of the 17 patients. The overall success rate was 59%, with a 41% revision rate. Understanding the parameters leading to success or failure will be critical in advancing a reliable definitive nonfusion treatment for progressive scoliosis in the future. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Dynamic Scoliosis Correction as Alternative Treatment for Patients with Adolescent Idiopathic Scoliosis: a Non-Fusion Surgical Technique

“…Somewhat sobering results were published by the group working with Peter Newton from San Diego which calculated a high revision rate [14]. The 2-to 4-year results (average 2.5 years) of 17 patients with thoracic scoliosis revealed an average correction of 51 %, however with a very broad variance (5 % to 118 %).…”

Feasibility of Single-Staged Bilateral Anterior Scoliosis Correction in Growing Patients

“…There is a paucity of studies on DSC and VBT and, to the best of our knowledge, these studies only analyzed patients undergoing unilateral surgery. [7][8][9] This study addresses patients with double curves who may be candidates for DSC. It helps establish a baseline of data to compare with patients undergoing posterior spinal fusion.…”

Learning curve for vertebral body tethering: analysis on 90 consecutive patients

“…This technique allows for curve correction while maintaining spine mobility, which is of particular relevance in the lumbar spine. VBT has been investigated with promising results [1][2][3][4][5][6][7][8], but further research is being conducted to define the role of VBT in the treatment of AIS and to identify the ideal candidate for this intervention. VBT was developed to employ the Hüter-Volkmann principle to modulate spine growth through a unilateral block of growth plates [9][10][11].…”