Safaee Michael M, Deviren Vedat, Dalle Ore Cecilia, Scheer Justin K, Lau Darryl, Osorio Joseph A, Nicholls Fred, Ames Christopher P
Departments of1Neurological Surgery and.
2Orthopedic Surgery, University of California, San Francisco, California.
J Neurosurg Spine. 2018 May;28(5):512-519. doi: 10.3171/2017.9.SPINE1710. Epub 2018 Feb 23.
OBJECTIVE Proximal junctional kyphosis (PJK) is a well-recognized, yet incompletely defined, complication of adult spinal deformity surgery. There is no standardized definition for PJK, but most studies describe PJK as an increase in the proximal junctional angle (PJA) of greater than 10°-20°. Ligament augmentation is a novel strategy for PJK reduction that provides strength to the upper instrumented vertebra (UIV) and adjacent segments while also reducing junctional stress at those levels. METHODS In this study, ligament augmentation was used in a consecutive series of adult spinal deformity patients at a single institution. Patient demographics, including age; sex; indication for surgery; revision surgery; surgical approach; and use of 3-column osteotomies, vertebroplasty, or hook fixation at the UIV, were collected. The PJA was measured preoperatively and at last follow-up using 36-inch radiographs. Data on change in PJA and need for revision surgery were collected. Univariate and multivariate analyses were performed to identify factors associated with change in PJA and proximal junctional failure (PJF), defined as PJK requiring surgical correction. RESULTS A total of 200 consecutive patients were included: 100 patients before implementation of ligament augmentation and 100 patients after implementation of this technique. The mean age of the ligament augmentation cohort was 66 years, and 67% of patients were women. Over half of these cases (51%) were revision surgeries, with 38% involving a combined anterior or lateral and posterior approach. The mean change in PJA was 6° in the ligament augmentation group compared with 14° in the control group (p < 0.001). Eighty-four patients had a change in PJA of less than 10°. In a multivariate linear regression model, age (p = 0.016), use of hook fixation at the UIV (p = 0.045), and use of ligament augmentation (p < 0.001) were associated with a change in PJA. In a separate model, only ligament augmentation (OR 0.193, p = 0.012) showed a significant association with PJF. CONCLUSIONS Ligament augmentation represents a novel technique for the prevention of PJK and PJF. Compared with a well-matched historical cohort, ligament augmentation is associated with a significant decrease in PJK and PJF. These data support the implementation of ligament augmentation in surgery for adult spinal deformity, particularly in patients with a high risk of developing PJK and PJF.
目的 近端交界性后凸（PJK）是成人脊柱畸形手术中一种已被充分认识但定义尚不完整的并发症。目前尚无PJK的标准化定义，但大多数研究将PJK描述为近端交界角（PJA）增加超过10°-20°。韧带增强是一种减少PJK的新策略，可增强上位固定椎体（UIV）及相邻节段的强度，同时也可减轻这些节段的交界性应力。方法 在本研究中，一所机构对一系列连续的成人脊柱畸形患者采用了韧带增强技术。收集了患者的人口统计学资料，包括年龄、性别、手术指征、翻修手术、手术入路以及UIV处是否使用三柱截骨术、椎体成形术或钩固定。术前及末次随访时使用36英寸X线片测量PJA。收集PJA变化及翻修手术需求的数据。进行单因素和多因素分析以确定与PJA变化及近端交界性失败（PJF，定义为需要手术矫正的PJK）相关的因素。结果 共纳入200例连续患者：100例在实施韧带增强技术之前，100例在实施该技术之后。韧带增强组患者的平均年龄为66岁，67%为女性。这些病例中超过一半（51%）为翻修手术，38%涉及前后联合或侧后联合入路。韧带增强组PJA的平均变化为6°，而对照组为14°（p<0.001）。84例患者的PJA变化小于10°。在多因素线性回归模型中，年龄（p=0.016）、UIV处使用钩固定（p=0.045）以及使用韧带增强（p<0.001）与PJA变化相关。在另一个模型中，只有韧带增强（OR 0.193，p=0.012）与PJF有显著相关性。结论 韧带增强是预防PJK和PJF的一种新技术。与匹配良好的历史队列相比，韧带增强与PJK和PJF的显著降低相关。这些数据支持在成人脊柱畸形手术中实施韧带增强技术，尤其是在发生PJK和PJF风险较高的患者中。
