Bohl Michael A, McBryan Sarah, Newcomb Anna G U S, Lehrman Jennifer N, Kelly Brian P, Nakaji Peter, Chang Steve W, Uribe Juan S, Turner Jay D, Kakarla U Kumar
Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA.
Global Spine J. 2020 Jun;10(4):419-424. doi: 10.1177/2192568219858981. Epub 2019 Jun 23.
Biomechanical model study.
The Barrow Biomimetic Spine (BBS) project is a resident-driven effort to manufacture a synthetic spine model with high biomechanical fidelity to human tissue. The purpose of this study was to investigate the performance of the current generation of BBS models on biomechanical testing of range of motion (ROM) and axial compression and to compare the performance of these models to historical cadaveric data acquired using the same testing protocol.
Six synthetic spine models comprising L3-5 segments were manufactured with variable soft-tissue densities and print orientations. Models underwent torque loading to a maximum of 7.5 N m. Torques were applied to the models in flexion-extension, lateral bending, axial rotation, and axial compression. Results were compared with historic cadaveric control data.
Each model demonstrated steadily decreasing ROM on flexion-extension testing with increasing density of the intervertebral discs and surrounding ligamentous structures. Vertically printed models demonstrated markedly less ROM than equivalent models printed horizontally at both L3-4 (5.0° vs 14.0°) and L4-5 (3.9° vs 15.2°). Models D and E demonstrated ROM values that bracketed the cadaveric controls at equivalent torque loads (7.5 N m).
This study identified relevant variables that affect synthetic spine model ROM and compressibility, confirmed that the models perform predictably with changes in these print variables, and identified a set of model parameters that result in a synthetic model with overall ROM that approximates that of a cadaveric model. Future studies can be undertaken to refine model performance and determine intermodel variability.
生物力学模型研究。
巴罗仿生脊柱（BBS）项目是一项由住院医师推动的工作，旨在制造一种对人体组织具有高生物力学保真度的合成脊柱模型。本研究的目的是研究当前一代BBS模型在运动范围（ROM）和轴向压缩的生物力学测试中的性能，并将这些模型的性能与使用相同测试方案获取的历史尸体数据进行比较。
制造了六个包含L3 - 5节段的合成脊柱模型，其软组织密度和打印方向各不相同。对模型施加最大7.5 N·m的扭矩加载。在屈伸、侧弯、轴向旋转和轴向压缩时对模型施加扭矩。将结果与历史尸体对照数据进行比较。
在屈伸测试中，随着椎间盘和周围韧带结构密度的增加，每个模型的ROM均呈稳步下降趋势。垂直打印的模型在L3 - 4（5.0°对14.0°）和L4 - 5（3.9°对15.2°）处的ROM明显低于水平打印的等效模型。模型D和E在等效扭矩载荷（7.5 N·m）下的ROM值介于尸体对照之间。
本研究确定了影响合成脊柱模型ROM和可压缩性的相关变量，证实了这些模型在这些打印变量变化时表现出可预测性，并确定了一组模型参数，这些参数可使合成模型的整体ROM接近尸体模型ROM。未来可开展研究以优化模型性能并确定模型间的变异性。
