University of Miami Miller School of Medicine, Department of Neurological Surgery, Miami, FL, USA.
University of Miami Miller School of Medicine, Department of Neurological Surgery, Miami, FL, USA.
J Clin Neurosci. 2021 Jun;88:150-156. doi: 10.1016/j.jocn.2021.03.031. Epub 2021 Apr 7.
Proximal junctional kyphosis is a kyphotic deformity following spine instrumentation, predominantly seen in scoliosis patients. There have been previous attempts to develop classification schema of PJK. We analyzed the factors contributing to PJK based upon our own clinical experience with the goal of developing a clinical guidance tool which took into account both etiology and mechanism of failure.
We performed a retrospective analysis of all re-operation thoracolumbar surgeries at a single institution over a 14-year period. Patients with PJK were identified and categorized based upon the etiology, mechanism of failure, and an indication of revision. Next, we conducted a systematic review on articles emphasizing a classification system for PJK.
Fourteen PJK patients were identified out of 121 patients who required revision spine surgery. The average age was 64.9 ± 10.2 years, with 10 males (71%) and 4 females (29%). Three primary etiologies were identified: 6/14 (47%) overcorrection, 6/14 (47%) osteopenia, and 2/14 (14%) ligamentous disruption. The mechanism of failure was likewise divided into three categories: 9/14 (64%) compression fracture, 1/14 (7%) hardware failure, and 4/14 (29%) disc degeneration. The relationship between osteopenia and the development of a compression fracture leading to PJK was statistically significant (p = 0.031).
There are multiple current classification systems for PJK. Our study findings were in line with previously published literature and suggest the need for a future classification system combining both etiology, mechanism of failure, and severity of disease.
近端交界性后凸是脊柱器械固定后出现的后凸畸形，主要见于脊柱侧凸患者。此前已经有过开发 PJK 分类方案的尝试。我们根据自己的临床经验分析了导致 PJK 的因素，旨在开发一种临床指导工具，该工具同时考虑了病因和失败机制。
我们对一家机构在 14 年内进行的所有返修胸腰椎手术进行了回顾性分析。根据病因、失败机制和翻修指征，确定并分类 PJK 患者。然后，我们对强调 PJK 分类系统的文章进行了系统综述。
在需要进行脊柱翻修手术的 121 名患者中，发现了 14 名 PJK 患者。平均年龄为 64.9 ± 10.2 岁，男性 10 名（71%），女性 4 名（29%）。确定了三个主要病因：14 例中的 6 例（47%）为过度矫正，6 例（47%）为骨质疏松，2 例（14%）为韧带断裂。失败的机制也分为三类：14 例中的 9 例（64%）为压缩性骨折，1 例（7%）为器械故障，4 例（29%）为椎间盘退变。骨质疏松症与导致 PJK 的压缩性骨折的发生之间存在统计学显著相关性（p = 0.031）。
目前有多种 PJK 分类系统。我们的研究结果与之前发表的文献一致，表明需要开发一种新的分类系统，该系统结合病因、失败机制和疾病严重程度。
