Department of Orthopaedics, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, No. 3, Qingchun Rd East, Hangzhou 310016, China.
Department of Orthopaedics, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, No. 3, Qingchun Rd East, Hangzhou 310016, China.
Spine J. 2018 Mar;18(3):472-481. doi: 10.1016/j.spinee.2017.08.237. Epub 2017 Aug 18.
The basivertebral foramen (BF), located in the middle posterior wall of the vertebral body, may induce local weakness and contribute to the formation of a retropulsed bone fragment (RBF) in thoracolumbar burst fracture (TLBF). We hypothesize that the mechanism of TLBF is related to the BF.
This study aimed to clarify the relationship between RBFs and the BF in TLBFs, and to explain the results using biomechanical experiments and micro-computed tomography (micro-CT).
A comprehensive research involving clinical radiology, micro-CT, and biomechanical experiments on cadaveric spines was carried out.
A total of 162 consecutive patients diagnosed with TLBF with RBFs, drawn from 256 patients who had reported accidents or injuries to their thoracolumbar spine, comprised the patient sample.
Dimensions and location of the RBFs in relation to the BF were the outcome measures.
Computed tomography reconstruction imaging was used to measure the dimensions and location of RBFs in 162 patients (length, height, width of RBF and vertebral body). Furthermore, micro-CT scans were obtained of 10 cadaveric spines. Each vertebral body was divided into three layers (superior, middle, and inferior), and each layer was divided further into nine regions (R1-R9). Microarchitecture parameters were calculated from micro-CT scans, including bone volume fraction (BV/TV), connectivity (Conn.D), trabecular number (Tb.N), trabecular thickness (Tb.Th), and bone mineral density (BMD). Differences were analyzed between regions and layers. Burst fractures were simulated on cadaveric spines to explore the fracture line location and test the relationship between RBFs and BF.
Retropulsed bone fragment width was usually one-third of the width of the vertebral body, whereas RBF length and height were approximately half of the corresponding vertebral body dimensions. Measures of trabecular bone quality were generally lowest in those central and superior regions of the vertebral body which are adjacent to the BF and which are most affected by burst fracture. In simulated TLBFs, the fracture line went across the vertex or upper surface of the BF.
The most vulnerable regions in the vertebral body lie within or just superior to the BF. The central MR2 region in particular is at risk of fracture and RBF formation.
椎弓根下切迹（BF）位于椎体的中后壁，可能导致局部薄弱，并有助于形成胸腰椎爆裂骨折（TLBF）的逆行骨碎片（RBF）。我们假设 TLBF 的机制与 BF 有关。
本研究旨在阐明 TLBF 中 RBF 与 BF 的关系，并通过生物力学实验和微计算机断层扫描（micro-CT）来解释结果。
对 162 例连续诊断为 TLBF 伴 RBF 的患者进行了包括临床放射学、微 CT 和尸体脊柱生物力学实验的综合研究。
从报告胸腰椎脊柱外伤或损伤的 256 例患者中抽取了 162 例连续诊断为 TLBF 伴 RBF 的患者作为患者样本。
RBF 与 BF 的关系的测量指标为 RBF 的尺寸和位置。
使用计算机断层扫描重建成像测量 162 例患者（RBF 的长度、高度、宽度和椎体）的 RBF 尺寸和位置。此外，对 10 具尸体脊柱进行了 micro-CT 扫描。每个椎体分为三层（上、中、下），每一层又分为九个区域（R1-R9）。从 micro-CT 扫描中计算出微结构参数，包括骨体积分数（BV/TV）、连通性（Conn.D）、骨小梁数量（Tb.N）、骨小梁厚度（Tb.Th）和骨密度（BMD）。分析了区域和层之间的差异。在尸体脊柱上模拟爆裂骨折，以探讨骨折线的位置，并检验 RBF 与 BF 的关系。
RBF 的宽度通常为椎体宽度的三分之一，而 RBF 的长度和高度约为相应椎体尺寸的一半。靠近 BF 且受爆裂骨折影响最大的椎体中央和上部区域的小梁骨质量测量值通常最低。在模拟 TLBF 中，骨折线穿过 BF 的顶点或上表面。
椎体中最脆弱的区域位于 BF 内或刚好在 BF 上方。特别是中央 MR2 区域易发生骨折和 RBF 形成。
