Adler Daniel, Akbar Michael, Spicher Anna, Goerke Stephanie-Alice, Schmoelz Werner
Spine Center, Department of Orthopaedic Surgery, Trauma Surgery and Division of Spinal Cord Injury, Ruprecht-Karls-University Heidelberg, Schlierbacher Landstraße 200A, 69118 Heidelberg, Germany.
Department of Trauma Surgery, Medical University of Innsbruck, Innrain 52, 6020 Innsbruck, Austria.
Materials (Basel). 2019 Aug 26;12(17):2732. doi: 10.3390/ma12172732.
Vertebral body replacement is well-established to stabilize vertebral injuries due to trauma or cancer. Spinal implants are mainly manufactured by metallic alloys; which leads to artifacts in radiological diagnostics; as well as in radiotherapy. The purpose of this study was to evaluate the biomechanical data of a novel carbon fiber reinforced polyetheretherketone (CF/PEEK) vertebral body replacement (VBR). Six thoracolumbar specimens were tested in a six degrees of freedom spine tester. In all tested specimens CF/PEEK pedicle screws were used. Two different rods (CF/PEEK versus titanium) with/without cross connectors and two different VBRs (CF/PEEK prototype versus titanium) were tested. In lateral bending and flexion/extension; range of motion (ROM) was significantly reduced in all instrumented states. In axial rotation; the CF/PEEK combination (rods and VBR) resulted in the highest ROM; whereas titanium rods with titanium VBR resulted in the lowest ROM. Two cross connectors reduced ROM in axial rotation for all instrumentations independently of VBR or rod material. All instrumented states in all planes of motion showed a significantly reduced ROM. No significant differences were detected between the VBR materials in all planes of motion. Less rigid CF/PEEK rods in combination with the CF/PEEK VBR without cross connectors showed the smallest reduction in ROM. Independently of VBR and rod material; two cross connectors significantly reduced ROM in axial rotation. Compared to titanium rods; the use of CF/PEEK rods results in higher ROM. The stiffness of rod material has more influence on the ROM than the stiffness of VBR material.
椎体置换术已被广泛应用于稳定因创伤或癌症导致的椎体损伤。脊柱植入物主要由金属合金制造；这会在放射诊断以及放射治疗中产生伪影。本研究的目的是评估一种新型碳纤维增强聚醚醚酮（CF/PEEK）椎体置换物（VBR）的生物力学数据。六个胸腰椎标本在六自由度脊柱测试仪上进行测试。所有测试标本均使用CF/PEEK椎弓根螺钉。测试了两种不同的杆（CF/PEEK与钛合金），有无横向连接，以及两种不同的VBR（CF/PEEK原型与钛合金）。在侧弯和屈伸运动中，所有植入状态下的活动范围（ROM）均显著减小。在轴向旋转中，CF/PEEK组合（杆和VBR）导致的ROM最高，而钛合金杆与钛合金VBR导致的ROM最低。两个横向连接独立于VBR或杆材料，在所有植入物的轴向旋转中均减小了ROM。所有运动平面中的所有植入状态均显示ROM显著减小。在所有运动平面中，未检测到VBR材料之间存在显著差异。刚性较小的CF/PEEK杆与无横向连接的CF/PEEK VBR组合显示ROM减小最小。独立于VBR和杆材料，两个横向连接在轴向旋转中显著减小了ROM。与钛合金杆相比，使用CF/PEEK杆会导致更高的ROM。杆材料的刚度对ROM的影响比VBR材料的刚度更大。
