Abstract：
BACKGROUND: The addition of the L4 \"AR\" and \"AL\" lumbar modifier for Lenke 1A idiopathic scoliosis (IS) has been shown to direct treatment in posterior spinal fusion; however, its utility in vertebral body tethering (VBT) has yet to be evaluated.
METHODS: A review of a prospective, multicenter database for VBT in IS was performed for patients with Lenke 1A deformities and a minimum of 2 years follow-up. Patients were categorized by their lumbar modifier (AR vs AL). Less optimal VBT outcome (LOVO) was defined as a final coronal curve > 35°, lumbar adding-on, or revision surgery for deformity progression or adding-on.
RESULTS: Ninety-nine patients met inclusion criteria (81% female, mean 12.6 years), with 55.6% being AL curves. Overall, there were 23 instances of tether breakage (23.3%) and 20 instances of LOVO (20.2%). There was a higher rate of LOVO in AR curves (31.8% vs 10.9%, P = 0.01). Patients with LOVO had greater preoperative deformity, greater apical translation, larger coronal deformity on first erect radiographs, and less coronal deformity correction. Failure to correct the deformity < 30° on first erect was associated with LOVO, as was LIV selection short of the last touch vertebra (TV). Independent risk factors for LOVO included AR curves (OR 3.4; P = 0.04) and first erect curve magnitudes > 30 degrees (OR 6.0; P = 0.002).
CONCLUSIONS: There is a 20.2% rate of less optimal VBT following VBT for Lenke 1A curves. AR curves are independently predictive of less optimal outcomes following VBT and require close attention to LIV selection. Surgeons should consider achieving an initial coronal correction < 30 degrees and extending the LIV to at least the TV to minimize the risk of LOVO.
METHODS: A review of a prospective, multicenter database for VBT in IS was performed for patients with Lenke 1A deformities and a minimum of 2 years follow-up. Patients were categorized by their lumbar modifier (AR vs AL). Less optimal VBT outcome (LOVO) was defined as a final coronal curve > 35°, lumbar adding-on, or revision surgery for deformity progression or adding-on.
RESULTS: Ninety-nine patients met inclusion criteria (81% female, mean 12.6 years), with 55.6% being AL curves. Overall, there were 23 instances of tether breakage (23.3%) and 20 instances of LOVO (20.2%). There was a higher rate of LOVO in AR curves (31.8% vs 10.9%, P = 0.01). Patients with LOVO had greater preoperative deformity, greater apical translation, larger coronal deformity on first erect radiographs, and less coronal deformity correction. Failure to correct the deformity < 30° on first erect was associated with LOVO, as was LIV selection short of the last touch vertebra (TV). Independent risk factors for LOVO included AR curves (OR 3.4; P = 0.04) and first erect curve magnitudes > 30 degrees (OR 6.0; P = 0.002).
CONCLUSIONS: There is a 20.2% rate of less optimal VBT following VBT for Lenke 1A curves. AR curves are independently predictive of less optimal outcomes following VBT and require close attention to LIV selection. Surgeons should consider achieving an initial coronal correction < 30 degrees and extending the LIV to at least the TV to minimize the risk of LOVO.
摘要：
背景：Lenke1A特发性脊柱侧凸（IS）的L4\“AR\”和\“AL\”腰椎调节器的添加已被证明可以直接治疗后路脊柱融合术；但是，其在椎体束缚（VBT）中的实用性尚待评估。
方法：对前瞻性，对Lenke1A畸形患者进行了IS中VBT的多中心数据库，并至少进行了2年的随访。患者按腰椎调节器（ARvsAL）进行分类。不太理想的VBT结果（LOVO）被定义为最终的冠状曲线>35°，腰部加装,或畸形进展或附加的翻修手术。
结果：99例患者符合纳入标准（81%为女性，平均12.6年)，55.6%为AL曲线。总的来说,有23例(23.3%)的系绳断裂和20例(20.2%)的LOVO。AR曲线中LOVO的发生率较高（31.8%vs10.9%，P=0.01）。LOVO患者术前畸形较大，更大的顶端翻译，第一次直立射线照片上的冠状畸形较大，冠状畸形矫正较少。第一次直立时未能纠正<30°的畸形与LOVO有关，LIV选择的最后一个接触椎骨（电视）。LOVO的独立危险因素包括AR曲线（OR3.4;P=0.04）和第一直立曲线幅度>30度（OR6.0;P=0.002）。
结论:对于Lenke1A曲线,在VBT之后存在20.2%的较不理想的VBT。AR曲线可独立预测VBT后较差的结果，需要密切关注LIV选择。外科医生应考虑实现<30度的初始冠状校正，并将LIV至少扩展到电视，以最大程度地减少LOVO的风险。
方法：对前瞻性，对Lenke1A畸形患者进行了IS中VBT的多中心数据库，并至少进行了2年的随访。患者按腰椎调节器（ARvsAL）进行分类。不太理想的VBT结果（LOVO）被定义为最终的冠状曲线>35°，腰部加装,或畸形进展或附加的翻修手术。
结果：99例患者符合纳入标准（81%为女性，平均12.6年)，55.6%为AL曲线。总的来说,有23例(23.3%)的系绳断裂和20例(20.2%)的LOVO。AR曲线中LOVO的发生率较高（31.8%vs10.9%，P=0.01）。LOVO患者术前畸形较大，更大的顶端翻译，第一次直立射线照片上的冠状畸形较大，冠状畸形矫正较少。第一次直立时未能纠正<30°的畸形与LOVO有关，LIV选择的最后一个接触椎骨（电视）。LOVO的独立危险因素包括AR曲线（OR3.4;P=0.04）和第一直立曲线幅度>30度（OR6.0;P=0.002）。
结论:对于Lenke1A曲线,在VBT之后存在20.2%的较不理想的VBT。AR曲线可独立预测VBT后较差的结果，需要密切关注LIV选择。外科医生应考虑实现<30度的初始冠状校正，并将LIV至少扩展到电视，以最大程度地减少LOVO的风险。
