Daentzer Dorothea, Willbold Elmar, Kalla Katharina, Bartsch Ivonne, Masalha Waseem, Hallbaum Maximiliane, Hurschler Christof, Kauth Theresa, Kaltbeitzel Daniel, Hopmann Christian, Welke Bastian
*Department of Orthopedics, Spine Section, Hannover Medical School, Diakoniekrankenhaus Annastift gGmbH, Hannover, Germany †Laboratory for Biomechanics and Biomaterials, Hannover Medical School, Hannover, Germany ‡Neurosurgical Clinic, University Freiburg, Freiburg, Germany; and §Institute of Plastics Processing at RWTH Aachen, Aachen, Germany.
Spine (Phila Pa 1976). 2014 Sep 15;39(20):E1220-7. doi: 10.1097/BRS.0000000000000507.
An experimental study using a sheep cervical spine interbody fusion model.
First, to compare anterior cervical discectomy and fusion of an experimental bioabsorbable cage consisting of a magnesium alloy and a polymer (poly-ε-caprolactone, PCL) with an autologous tricortical iliac crest bone graft. Second, to determine the degradation kinetics of the cage, assess the 2 fusion devices for biomechanical stability, and determine their histological characteristics.
Bioabsorbable cages are not routinely used in spine surgery at present, due to some undesirable effects such as cracks and foreign body reactions. This study involved the manufacture of a bioabsorbable cage from a magnesium alloy and the polymer PCL, which was then used as a device for anterior cervical discectomy and fusion in a sheep cervical spine fusion model.
Twenty-four sheep had anterior cervical discectomy and fusion of C3-C4 and C5-C6 with an experimental bioabsorbable cage consisting of the magnesium alloy AZ31, which was infiltrated and covered with PCL at 1 level and with an autologous tricortical iliac crest bone graft at a second level. The sheep were divided into 4 groups. After 3, 6, 12, or 24 weeks postimplantation, the animals were killed and the cervical spines were harvested. The intervertebral spaces with the cage were investigated using μ-computed tomographic images to calculate degradation kinetics. Stiffness of all monosegments was determined through biomechanical testing. Histological analysis was performed to evaluate fusion status and to detect any foreign body reactions. The results from both implants were compared.
The magnesium-PCL cage showed nonlinear degradation over time. Both implants demonstrated time-dependent increases in stability, with a significantly greater stiffness of the bone graft after 24 weeks in all directions of motion. Histologically, the cage showed no signs of fusion with progressive encapsulation over time.
In comparison with the bone graft, the bioabsorbable cage showed inferior stiffness and fusion properties. Thus, further component modifications are necessary.
N/A.
一项使用绵羊颈椎椎间融合模型的实验研究。
第一，比较使用由镁合金和聚合物（聚ε-己内酯，PCL）组成的实验性生物可吸收椎间融合器进行颈椎前路椎间盘切除融合术与自体三面皮质髂嵴骨移植的效果。第二，确定椎间融合器的降解动力学，评估两种融合装置的生物力学稳定性，并确定其组织学特征。
由于存在诸如裂缝和异物反应等不良影响，生物可吸收椎间融合器目前在脊柱手术中并非常规使用。本研究涉及用镁合金和聚合物PCL制造一种生物可吸收椎间融合器，然后将其用作绵羊颈椎融合模型中颈椎前路椎间盘切除融合术的装置。
24只绵羊在C3 - C4和C5 - C6节段进行颈椎前路椎间盘切除融合术，其中1个节段使用由AZ31镁合金制成并渗透和覆盖PCL的实验性生物可吸收椎间融合器，另1个节段使用自体三面皮质髂嵴骨移植。绵羊被分为4组。植入后3、6、12或24周，处死动物并取出颈椎。使用μ-计算机断层扫描图像研究植入椎间融合器的椎间隙以计算降解动力学。通过生物力学测试确定所有单节段的刚度。进行组织学分析以评估融合状态并检测任何异物反应。比较两种植入物的结果。
镁 - PCL椎间融合器随时间呈非线性降解。两种植入物的稳定性均随时间增加，在24周后，骨移植在所有运动方向上的刚度明显更大。组织学上，椎间融合器未显示融合迹象，且随时间逐渐被包裹。
与骨移植相比，生物可吸收椎间融合器的刚度和融合性能较差。因此，需要进一步对部件进行改进。
无。
