Upasani Vidyadhar V, Farnsworth Christine L, Caffrey Jason P, Olmert Tony, Brink Ian, Cain Phoebe, Mannen Erin
Department of Orthopaedic Surgery, University of California San Diego, San Diego, California, USA.
Division of Orthopedics and Scoliosis, Rady Children's Hospital, San Diego, California, USA.
J Orthop Res. 2025 Feb;43(2):441-445. doi: 10.1002/jor.25995. Epub 2024 Oct 10.
Vertebral body tethering (VBT) uses a flexible tether affixed across the curve convexity with tension applied at each segment to treat scoliosis. Intraoperative tether tension may be achieved directly with a counter-tensioner or with an extension spring tube. The purpose of this study was to quantify the force generated with and without the extension spring tube using current FDA-approved VBT instrumentation, to understand the variation between surgeons using the same instrumentation, and to define the force range that is generated intra-operatively. Using a benchtop mechanical testing setup to simulate a spinal segment, we affixed the tether and applied tension using a tensioner and counter-tensioner alone (method T1) or by adding an extension spring tube (method T2). Eight orthopedic surgeons used T1 and T2 at six tensioner settings, and one surgeon completed three trials. A two-way ANOVA with a Tukey's HSD post hoc test (p < 0.05) compared the tensioner methods and testing levels. Inter- and intra-rater reliabilities were calculated using intraclass correlation coefficients (ICCs). Methods T1 and T2 exhibited linear tension-setting relationships, with high determination coefficients (R > 0.93). T2 consistently produced higher forces (increase of 62.1 N/setting), compared to T1 (increase of 50.6 N/setting, p < 0.05). Inter-rater reliability exhibited excellent agreement (ICC = 0.951 and 0.943 for T1 and T2, respectively), as did intra-rater reliability (ICC = 0.971).
椎体拴系术（VBT）使用一根柔性拴系物固定在脊柱侧弯的凸侧，并在每个节段施加张力来治疗脊柱侧弯。术中拴系物张力可直接通过反向张力器或延长弹簧管来实现。本研究的目的是使用目前美国食品药品监督管理局（FDA）批准的VBT器械，量化使用和不使用延长弹簧管时产生的力，了解使用相同器械的外科医生之间的差异，并确定术中产生的力的范围。我们使用台式机械测试装置模拟一个脊柱节段，单独使用张力器和反向张力器（方法T1）或添加延长弹簧管（方法T2）来固定拴系物并施加张力。八位骨科医生在六个张力器设置下使用T1和T2，一位医生完成了三次试验。采用双向方差分析和Tukey's HSD事后检验（p < 0.05）比较张力器方法和测试水平。使用组内相关系数（ICC）计算评分者间和评分者内的可靠性。方法T1和T2呈现出线性张力设置关系，决定系数较高（R > 0.93）。与T1（每个设置增加50.6 N，p < 0.05）相比，T2始终产生更高的力（每个设置增加62.1 N）。评分者间可靠性表现出极好的一致性（T1和T2的ICC分别为0.951和0.943），评分者内可靠性也是如此（ICC = 0.971）。
