Silk Zacharia Matthew, Tishelman Jared C, Eaker Lily, Lonner Baron
Department of Neurosciences, Leeds General Infirmary, Leeds, UK.
Department of Orthopaedic Surgery, Mount Sinai Hospital, New York, NY, USA.
Global Spine J. 2024 Jan;14(1):219-224. doi: 10.1177/21925682221100444. Epub 2022 May 5.
Retrospective Cohort Study.
Mid-term Anterior Vertebral Body Tethering (AVBT) results demonstrate an acceptable degree of clinical success, yet the revision rate remains notably higher than fusion. Fulcrum-bending radiographs have previously been shown to more reliably predict radiological outcomes in Adolescent Idiopathic Scoliosis (AIS) as compared to supine-lateral bending radiographs. This study aims to discern how Fulcrum Flexibility Rate (FFR) correlates with Correction Rate (CR) and establish whether this can reliably predict residual deformity following AVBT surgery.
A review of 38 consecutive AIS patients undergoing thoracic AVBT between 2015 - 2020 was performed. Preoperative (standing and fulcrum-bending) and postoperative (first-erect) radiographs were evaluated for curve magnitude using the Cobb-method. The FFR, CR and Fulcrum Bending Correction Index (FBCI) were calculated. Patients were also percentile-ranked according to their FFR and dichotomized into flexible and rigid cohorts for comparison. Student t-test, Pearson correlation and linear stepwise regression was applied.
AVBT resulted in a significant improvement in the major Cobb angle (Preoperative: 50.9±7.5° vs Postoperative: 19.9±9.4°; < .0001) with a mean FBCI of 98.0%. Bivariate correlation revealed a moderate relationship between fulcrum-bending and first-erect Cobb angle (r = .5306, = .0006). Linear regression demonstrated a predictive relationship between fulcrum-bending and first-erect Cobb using the equation 'Postoperative Cobb = 7.5 + .65(Fulcrum-bending Cobb).'
This is the first study to demonstrate the ability of fulcrum-bending radiographs to predict early radiographic outcomes following AVBT, 'timepoint-zero' for the growth modulation process.
回顾性队列研究。
中期前路椎体拴系术（AVBT）的结果显示出可接受的临床成功率，但翻修率仍显著高于融合术。与仰卧位侧弯X线片相比，支点弯曲X线片先前已被证明能更可靠地预测青少年特发性脊柱侧凸（AIS）的影像学结果。本研究旨在探讨支点柔韧性率（FFR）与矫正率（CR）之间的相关性，并确定这是否能可靠地预测AVBT手术后的残留畸形。
对2015年至2020年间连续接受胸椎AVBT的38例AIS患者进行回顾性研究。术前（站立位和支点弯曲位）和术后（首次直立位）X线片采用Cobb法评估侧弯角度。计算FFR、CR和支点弯曲矫正指数（FBCI）。患者还根据其FFR进行百分位数排序，并分为柔韧性和僵硬性队列进行比较。应用学生t检验、Pearson相关性分析和线性逐步回归分析。
AVBT使主要Cobb角显著改善（术前：50.9±7.5°，术后：19.9±9.4°；P <.0001），平均FBCI为98.0%。双变量相关性分析显示支点弯曲位和首次直立位Cobb角之间存在中度相关性（r = 0.5306，P = 0.0006）。线性回归分析显示，采用“术后Cobb角 = 7.5 + 0.65（支点弯曲位Cobb角） ”这一方程，支点弯曲位和首次直立位Cobb角之间存在预测关系。
这是第一项证明支点弯曲X线片能够预测AVBT术后早期影像学结果的研究，这是生长调节过程的“零时间点” 。
