Department of Orthopedic Surgery, The Johns Hopkins University, 601 N. Caroline St, JHOC 5223, Baltimore, MD, USA.
Department of Orthopedic Surgery, The Johns Hopkins University, 601 N. Caroline St, JHOC 5223, Baltimore, MD, USA.
Spine J. 2021 Jul;21(7):1072-1079. doi: 10.1016/j.spinee.2021.03.009. Epub 2021 Mar 13.
It is unknown whether upper instrumented vertebra (UIV) pedicle screw trajectory and UIV screw-rod angle are associated with development of proximal junctional kyphosis (PJK) and/or proximal junctional failure (PJF).
To determine whether (1) the cranial-caudal trajectory of UIV pedicle screws and (2) UIV screw-vertebra angle are associated with PJK and/or PJF after long posterior spinal fusion in patients with adult spinal deformity (ASD).
STUDY DESIGN/SETTING: Retrospective review.
We included 96 patients with ASD who underwent fusion from T9-T12 to the pelvis (>5 vertebrae fused) between 2008 and 2015.
Pedicle screw trajectory was measured as the UIV pedicle screw-vertebra angle (UIV-PVA), which is the mean of the two angles between the UIV superior endplate and both UIV pedicle screws. (Positive values indicate screws angled cranially; negative values indicate screws angled caudally.) We measured UIV rod-vertebra angle (UIV-RVA) between the rod at the point of screw attachment and the UIV superior endplate.
During ≥2-year follow-up, 38 patients developed PJK, and 28 developed PJF. Mean (± standard deviation) UIV-PVA was -0.9° ± 6.0°. Mean UIV-RVA was 87° ± 5.2°. We examined the development of PJK and PJF using a UIV-PVA/UIV-RVA cutoff of 3° identified by a receiver operating characteristic curve, while controlling for osteoporosis, age, sex, and preoperative thoracic kyphosis.
Patients with UIV-PVA ≥3° had significantly greater odds of developing PJK (odds ratio 2.7; 95% confidence interval: 1.0-7.1) and PJF (odds ratio 3.6; 95% confidence interval: 1.3-10) compared with patients with UIV-PVA <3°. UIV-RVA was not significantly associated with development of PJK or PJF.
In long thoracic fusion to the pelvis for ASD, UIV-PVA ≥3° was associated with 2.7-fold greater odds of PJK and 3.6-fold greater odds of PJF compared with UIV-PVA <3°. UIV-RVA was not associated with PJK or PJF.
III.
目前尚不清楚上节段椎弓根螺钉（UIV）轨道和 UIV 螺钉-杆角度是否与近端交界性后凸（PJK）和/或近端交界性失败（PJF）的发生有关。
确定（1）UIV 椎弓根螺钉的头尾向轨迹和（2）UIV 螺钉-椎体角度是否与成人脊柱畸形（ASD）患者长节段后路融合后 PJK 和/或 PJF 的发生有关。
研究设计/地点：回顾性研究。
我们纳入了 2008 年至 2015 年期间接受 T9-T12 至骨盆融合（>5 个椎体融合）的 96 例 ASD 患者。
椎弓根螺钉轨迹测量为 UIV 椎弓根螺钉-椎体角度（UIV-PVA），即 UIV 上终板与两个 UIV 椎弓根螺钉之间两个角度的平均值（正值表示螺钉向头侧成角；负值表示螺钉向尾侧成角）。我们测量了螺钉附着点处的杆与 UIV 上终板之间的 UIV 杆-椎体角度（UIV-RVA）。
在≥2 年的随访期间，38 例患者发生 PJK，28 例患者发生 PJF。UIV-PVA 的平均（±标准差）为-0.9°±6.0°。UIV-RVA 的平均为 87°±5.2°。我们通过受试者工作特征曲线确定 UIV-PVA/UIV-RVA 截点为 3°，同时控制骨质疏松症、年龄、性别和术前胸腰椎后凸角，以此来检测 PJK 和 PJF 的发生情况。
UIV-PVA≥3°的患者发生 PJK（优势比 2.7；95%置信区间：1.0-7.1）和 PJF（优势比 3.6；95%置信区间：1.3-10）的可能性明显高于 UIV-PVA<3°的患者。UIV-RVA 与 PJK 或 PJF 的发生无明显相关性。
在 ASD 患者长节段胸腰椎至骨盆融合中，与 UIV-PVA<3°的患者相比，UIV-PVA≥3°的患者 PJK 和 PJF 的发生风险分别增加 2.7 倍和 3.6 倍。UIV-RVA 与 PJK 或 PJF 无关。
III 级。
