Vertebral Body Tethering in 49 Adolescent Patients after Peak Height Velocity for the Treatment of Idiopathic Scoliosis: 2–5 Year Follow-Up

Vertebral Body Tethering (VBT) is a non-fusion surgical treatment for Adolescent Idiopathic Scoliosis (AIS) that elicits correction via growth modulation in skeletally immature patients. VBT after peak height velocity is controversial and is the subject of this study. A retrospective review of Risser 3–5 AIS patients treated with VBT, and min. 2-year FU was performed. Pre to post-op changes in clinical outcomes were compared using Student’s t-test or the Mann-Whitney test. A total of 49 patients met criteria, age 15.0 ± 1.9 years, FU 32.5 ± 9.1 months. For thoracic (T) major curvatures, T curvature improved from 51.1 ± 6.9^◦ to 27.2^◦ ± 8.1^◦ (p < 0.01) and TL from 37.2^◦ ± 10.7^◦ to 19.2^◦ ± 6.8^◦ (p < 0.01). For thoracolumbar (TL) major curvatures, T improved from 37.2^◦ ± 10.7^◦ to 18.8^◦ ± 9.4^◦ (p < 0.01) and TL from 49.0^◦ ± 6.4^◦ to 20.1^◦ ± 8.5^◦ (p < 0.01). Major curve inclinometer measurements and SRS-22 domains, except activity, improved significantly (p ≤ 0.05). At the latest FU, one (2%) patient required fusion of the T curve and revision of the TL tether due to curve progression in the previously uninstrumented T curve and tether breakage (TB) in the TL. Twenty (41%) patients experienced TB. VBT in AIS patients with limited remaining skeletal growth resulted in satisfactory clinical outcomes at the latest FU.