Abstract：
OBJECTIVE: There is variability in clinical outcomes with vertebral body tethering (VBT) partly due to a limited understanding of the growth modulation (GM) response. We used the largest sample of patients with 3D spine reconstructions to characterize the vertebra and disc morphologic changes that accompany growth modulation during the first two years following VBT.
METHODS: A multicenter registry was used to identify idiopathic scoliosis patients who underwent VBT with 2 years of follow-up. Calibrated biplanar X-rays obtained at longitudinal timepoints underwent 3D reconstruction to obtain precision morphological measurements. GM was defined as change in instrumented coronal angulation from post-op to 2-years.
RESULTS: Fifty patients (mean age: 12.5 ± 1.3yrs) were analyzed over a mean of 27.7 months. GM was positively correlated with concave vertebra height growth (r = 0.57, p < 0.001), 3D spine length growth (r = 0.36, p = 0.008), and decreased convex disc height (r = - 0.42, p = 0.002). High modulators (patients experiencing GM > 10°) experienced an additional 1.6 mm (229% increase) of mean concave vertebra growth during study period compared to the Poor Modulators (GM < - 10°) group, (2.3 vs. 0.7 mm, p = 0.039), while convex vertebra height growth was similar (1.3 vs. 1.4 mm, p = 0.91).
CONCLUSIONS: When successful, VBT enables asymmetric vertebra body growth, leading to continued postoperative coronal angulation correction (GM). A strong GM response is correlated with concave vertebral body height growth and overall instrumented spine growth. A poor GM response is associated with an increase in convex disc height (suspected tether rupture). Future studies will investigate the patient and technique-specific factors that influence increased growth remodeling.
METHODS: A multicenter registry was used to identify idiopathic scoliosis patients who underwent VBT with 2 years of follow-up. Calibrated biplanar X-rays obtained at longitudinal timepoints underwent 3D reconstruction to obtain precision morphological measurements. GM was defined as change in instrumented coronal angulation from post-op to 2-years.
RESULTS: Fifty patients (mean age: 12.5 ± 1.3yrs) were analyzed over a mean of 27.7 months. GM was positively correlated with concave vertebra height growth (r = 0.57, p < 0.001), 3D spine length growth (r = 0.36, p = 0.008), and decreased convex disc height (r = - 0.42, p = 0.002). High modulators (patients experiencing GM > 10°) experienced an additional 1.6 mm (229% increase) of mean concave vertebra growth during study period compared to the Poor Modulators (GM < - 10°) group, (2.3 vs. 0.7 mm, p = 0.039), while convex vertebra height growth was similar (1.3 vs. 1.4 mm, p = 0.91).
CONCLUSIONS: When successful, VBT enables asymmetric vertebra body growth, leading to continued postoperative coronal angulation correction (GM). A strong GM response is correlated with concave vertebral body height growth and overall instrumented spine growth. A poor GM response is associated with an increase in convex disc height (suspected tether rupture). Future studies will investigate the patient and technique-specific factors that influence increased growth remodeling.
摘要：
目的：椎体束缚（VBT）的临床结局存在差异，部分原因是对生长调节（GM）反应的理解有限。我们使用了最大的3D脊柱重建患者样本来表征VBT后头两年中伴随生长调节的椎骨和椎间盘形态变化。
方法：使用多中心注册来确定特发性脊柱侧凸患者接受VBT并随访2年。在纵向时间点获得的校准双平面X射线进行3D重建以获得精确的形态学测量。GM被定义为从术后到2年仪器化冠状角度的变化。
结果：对50名患者（平均年龄：12.5±1.3岁）进行了平均27.7个月的分析。GM与凹椎体高度生长呈正相关(r=0.57,p<0.001),3D脊柱长度增长（r=0.36，p=0.008），凸盘高度降低（r=-0.42，p=0.002）。与不良调节剂（GM<-10°）组相比，高调节剂（GM>10°的患者）在研究期间平均凹椎骨生长额外增加了1.6mm（增加229%）。（2.3vs.0.7mm,p=0.039),而凸椎骨高度生长相似(1.3与1.4mm,p=0.91）。
结论：当成功时，VBT使不对称的椎体生长，导致持续的术后冠状角度校正（GM）。强烈的GM反应与凹椎体高度增长和整体器械脊柱增长相关。不良的GM反应与凸盘高度增加（怀疑系绳破裂）有关。未来的研究将调查影响生长重塑增加的患者和技术特异性因素。
方法：使用多中心注册来确定特发性脊柱侧凸患者接受VBT并随访2年。在纵向时间点获得的校准双平面X射线进行3D重建以获得精确的形态学测量。GM被定义为从术后到2年仪器化冠状角度的变化。
结果：对50名患者（平均年龄：12.5±1.3岁）进行了平均27.7个月的分析。GM与凹椎体高度生长呈正相关(r=0.57,p<0.001),3D脊柱长度增长（r=0.36，p=0.008），凸盘高度降低（r=-0.42，p=0.002）。与不良调节剂（GM<-10°）组相比，高调节剂（GM>10°的患者）在研究期间平均凹椎骨生长额外增加了1.6mm（增加229%）。（2.3vs.0.7mm,p=0.039),而凸椎骨高度生长相似(1.3与1.4mm,p=0.91）。
结论：当成功时，VBT使不对称的椎体生长，导致持续的术后冠状角度校正（GM）。强烈的GM反应与凹椎体高度增长和整体器械脊柱增长相关。不良的GM反应与凸盘高度增加（怀疑系绳破裂）有关。未来的研究将调查影响生长重塑增加的患者和技术特异性因素。
