Lalande Viviane, Villemure Isabelle, Parent Stefan, Aubin Carl-Éric
Polytechnique Montréal, Montreal, Canada.
CHU Sainte-Justine, Montreal, Canada.
Spine Deform. 2020 Aug;8(4):585-589. doi: 10.1007/s43390-020-00070-z. Epub 2020 Feb 24.
Experimental biomechanical study of pressures exerted on the epiphyseal growth plates (GP) in tethered porcine cadaveric spines.
To experimentally measure the pressure exerted on the vertebral end plates of a tethered porcine spine model. Flexible spine tethering is a novel fusionless surgical technique that aims to correct scoliotic deformities based on growth modulation due to the pressure exerted on vertebral body epiphyseal GP. The applied pressure resulting from spine tethering remains not well documented.
The ligamentous thoracic segment (T1-T14) of four 3-months old Duroc Landrace pigs (female; 22 kg, range: 18-27 kg) was positioned in lateral decubitus in a custom-made stand. Vertebra T14 was clamped but the remaining spine was free to slide horizontally. For every specimen, six configurations were tested: three or five instrumented motion segments (T5-T10 or T7-T10) with applied compression of 22, 44 or 66 N. The pressure generated on the GPs in the tethered side was measured with a thin force sensor slid either at the proximal, apex or distal levels. The data were analyzed with an ANOVA.
The pressure was significantly different between three and five instrumented motion segments (averages of 0.76 MPa ± 0.03 and 0.60 MPa ± 0.03, respectively; p < 0.05), but the pressure exerted on each GP along the instrumented spine was not significantly different for a given number of instrumented levels. The pressure was linearly correlated to the tether tension.
Non segmental anterior spine tethering induced similar pressures on every instrumented level regardless of the number of instrumented levels, with 21% lesser pressures with 5 motion segments.
Level IV.
对固定的猪尸体脊柱骨骺生长板（GP）上施加的压力进行实验性生物力学研究。
通过实验测量固定的猪脊柱模型椎体终板上施加的压力。柔性脊柱固定是一种新型的非融合手术技术，旨在基于对椎体骨骺生长板施加的压力进行生长调节来矫正脊柱侧弯畸形。脊柱固定所施加的压力情况仍缺乏充分记录。
选取4只3月龄杜洛克长白猪（雌性；体重22千克，范围：18 - 27千克），将其胸段韧带（T1 - T14）置于定制支架的侧卧位。T14椎体被固定，但其余脊柱可自由水平滑动。对于每个标本，测试六种配置：三个或五个植入仪器的运动节段（T5 - T10或T7 - T10），施加22、44或66牛的压缩力。通过在近端、顶点或远端水平滑动的薄力传感器测量固定侧生长板上产生的压力。数据采用方差分析进行分析。
三个和五个植入仪器的运动节段之间压力有显著差异（分别平均为0.76兆帕±0.03和0.60兆帕±0.03；p < 0.05），但对于给定数量的植入仪器节段，沿植入仪器脊柱的每个生长板上施加的压力无显著差异。压力与固定张力呈线性相关。
非节段性前路脊柱固定在每个植入仪器的水平上产生相似的压力，与植入仪器节段的数量无关，五个运动节段时压力降低21%。
IV级。
