Outcomes and Complications of Vertebral Body Tethering in Skeletally Immature Patients with Idiopathic Scoliosis

Background: Vertebral body tethering (VBT) aims to gradually correct scoliosis using patients’ growth while preserving spinal motion. We report 5 to 8-year outcomes and complications in skeletally immature patients. Methods: This prospective single-center cohort study included 74 patients who had idiopathic scoliosis and a ≥5-year follow-up. Preoperative, first postoperative visit, 1-year, 2-year, and ≥5-year radiographs were analyzed. A ≥5° increase in the interscrew angle suggested tether breakage. Results: All 74 patients (5 male and 69 female) were skeletally immature at surgery. The mean age at surgery was 11.8 ± 1.3 years, and the mean follow-up time was 63.4 ± 8.4 months. Of the 74 patients, 68 patients were White, 4 were Black, and 2 were Middle Eastern or North African. VBT was performed on a mean of 7.4 vertebral levels. The maximum Cobb angle was 47.9° ± 9.4° preoperatively, whereas the instrumented Cobb angle measured 17.2° ± 12.3° at 2 years and 25.7° ± 14.0° at ≥5 years postoperatively. An unplanned return to the operating room occurred in 16 patients (21.6%). Forty-nine patients (66%) had a suspected broken tether at the final follow-up. The mean time of the first tether breakage was 38.1 ± 15 months. Forty-nine patients (66%) also had a curve of <40° without an unplanned return to the operating room at a minimum of 5 years postoperatively. Conclusions: In our cohort, 66% (49 patients) had a radiographically suspected tether breakage after 5 years and 13.5% (10 patients) required posterior spinal fusion to date. VBT yielded significant correction in the coronal plane (p < 0.001) and transverse plane (p = 0.006) postoperatively, with a reoperation rate of 21.6%. Level of Evidence: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.