1Department of Orthopedics and Spine Surgery, the First Affiliated Hospital of Anhui Medical University, Hefei.
2Laboratory of Spinal and Spinal Cord Injury Regeneration and Repair, the First Affiliated Hospital of Anhui Medical University, Hefei.
J Neurosurg Spine. 2024 May 24;41(2):199-208. doi: 10.3171/2024.2.SPINE231208. Print 2024 Aug 1.
The aim of this study was to design a novel lumbar cortical bone trajectory (CBT) penetrating the anterior, middle, and posterior vertebral area using imaging; measure the relevant parameters to find theoretical parameters and screw placement possibilities; and investigate the optimal implantation trajectory of the CBT in patients with osteoporosis.
Three types of CBTs with appropriate lengths were selected to simulate screw placement using Mimics software. These CBTs were classified as the leading tip of the trajectory pointing to the posterior quarter area (original CBT [CBT-O]) and middle (novel CBT A [CBT-A]) and anterior quarter (novel CBT B [CBT-B]) of the superior endplate. The authors then measured the maximum screw diameter (MSD) and length (MSL), cephalad (CA) and lateral (LA) angles, and bone mineral density (Hounsfield unit [HU] values) of the planned novel 3-column CBT screw placements. The differences in the parameters of the novel CBTs, the percentages of successfully planned CBT screws, and the factors that influenced the successful planning of 3-column CBT screws were analyzed.
Three-column CBT screws were successfully designed in all segments of the lumbar spine. The success rate of the 3-column CBT planned screws was 72.25% (83.25% for CBT-A and 61.25% for CBT-B). From the CBT-O type, to the CBT-A type, to the CBT-B type, the LA, CA, and MSD of the novel CBT screws decreased with increasing trajectory length. The HU values of the three types of trajectories were all significantly higher than that of the traditional pedicle screw trajectory (p < 0.001). The main factor affecting successful planning of the 3-column CBT screw was pedicle width.
Moderating adjustment of the original screw parameters by reducing LAs and CAs to penetrate the anterior, middle, and posterior columns of the vertebral body using the 3-column CBT screw is feasible, especially in the lower lumbar spine.
本研究旨在设计一种新的腰椎皮质骨轨迹（CBT），通过影像学穿透前、中、后椎体区域；测量相关参数，寻找理论参数和螺钉放置的可能性；并探讨骨质疏松患者 CBT 的最佳植入轨迹。
使用 Mimics 软件模拟三种适当长度的 CBT 进行螺钉放置。这些 CBT 分为轨迹尖端指向后四分之一区域（原始 CBT [CBT-O]）和中上四分之一（新型 CBT A [CBT-A]）和前四分之一（新型 CBT B [CBT-B]）的两种类型。作者然后测量了计划的新型 3 柱 CBT 螺钉放置的最大螺钉直径（MSD）和长度（MSL）、头侧（CA）和外侧（LA）角度以及骨矿物质密度（Hounsfield 单位 [HU] 值）。分析了新型 CBT 各参数之间的差异、新型 CBT 螺钉成功规划的百分比以及影响 3 柱 CBT 螺钉成功规划的因素。
在腰椎的所有节段均成功设计了 3 柱 CBT 螺钉。3 柱 CBT 计划螺钉的成功率为 72.25%（CBT-A 为 83.25%，CBT-B 为 61.25%）。从 CBT-O 型到 CBT-A 型再到 CBT-B 型，新型 CBT 螺钉的 LA、CA 和 MSD 随着轨迹长度的增加而减小。三种轨迹的 HU 值均明显高于传统椎弓根螺钉轨迹（p<0.001）。影响 3 柱 CBT 螺钉成功规划的主要因素是椎弓根宽度。
通过减少 LA 和 CA 来调节原始螺钉参数，使用 3 柱 CBT 螺钉穿透椎体的前、中、后柱是可行的，尤其是在腰椎下部。
