Objective To evaluate the interbody fusion efficacy and biocompatibility of a graft-free cage made of polyetheretherketone/calcium silicate composite/porous tantalum (PEEK/CS/pTa cage) compared with a PEEK/CS cage with an autogenous bone graft in a goat model. Methods PEEK/CS/pTa and PEEK/CS cages were prepared through an injection-moulding method. The PEEK/CS composites and porous tantalum were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) mapping. Then, adult goats were chosen for C2/C3 and C3/C4 discectomy via the anterior cervical approach and randomly implanted with PEEK/CS/pTa and PEEK/CS/cages with autogenous bone grafts. The fusion performance and osseointegration of the cages were evaluated by X-ray imaging, magnetic resonance imaging (MRI) scanning, and bone histomorphometry analysis. Moreover, the concentrations of Ca and Si in urine, serum, tissue around the fusion segments and major organs of the goats were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). Histological observation of major organs of the goats was used to evaluate the biosafety of PEEK/CS/pTa and PEEK/CS cages. Results X-ray and MRI imaging suggested that both PEEK/CS/pTa cages and PEEK/CS cages maintained similar average intervertebral space heights. The tissue volumes in the fusion area were comparable between the two groups of cages at 26 weeks after surgery. Histological morphometric data showed that PEEK/CS/pTa cages and PEEK/CS cages with autogenous bone grafts had similar bone contact and osseointegration at 12 and 26 weeks. Element determination of serum, urine, spinal cord, dura matter, bone and organs showed that the CS/PEEK cages did not cause abnormal systemic metabolism or accumulation of calcium and silicon in local tissues and major organs of goats after implantation. No obvious pathological changes were found in the heart, liver, spleen, liver or kidney tissues. Conclusion Overall, these results suggested that the graft-free PEEK/CS/pTa cage showed similar bony fusion performance to the PEEK/CS cages with autogenous bone grafts. The cages releasing calcium and silicon had good biological safety in vivo.The translational potential of this article: This study provided a new graft-free interbody fusion solution to patients with degenerative disc diseases, which could avert potential donor-site complications. This study also provided a detailed assessment of element excretion and accumulation of Ca and Si in vivo, which validated the biosafety of this new type of bioactive interbody fusion cage.

中文翻译：

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在山羊模型中评估聚醚醚酮/硅酸钙/多孔钽笼的体间融合功效和生物相容性。

目的在山羊模型中比较聚醚醚酮/硅酸钙复合材料/多孔钽（PEEK/CS/pTa 笼）与PEEK/CS 笼与自体骨移植物的椎体间融合效果和生物相容性。方法 PEEK/CS/pTa 和 PEEK/CS 保持架采用注塑成型方法制备。采用傅里叶变换红外光谱 (FTIR)、X 射线光电子能谱 (XPS)、X 射线衍射 (XRD)、扫描电子显微镜 (SEM) 和能量色散光谱 (EDS) 对 PEEK/CS 复合材料和多孔钽进行了表征) 映射。然后，通过颈前路入路选择成年山羊进行 C2/C3 和 C3/C4 椎间盘切除术，并随机植入 PEEK/CS/pTa 和 PEEK/CS/自体骨移植物笼。通过 X 射线成像、磁共振成像 (MRI) 扫描和骨组织形态学分析评估了融合器的融合性能和骨整合。此外，通过电感耦合等离子体发射光谱法（ICP-OES）测定了山羊尿液、血清、融合节段周围组织和主要器官中Ca和Si的浓度。山羊主要器官的组织学观察用于评估PEEK/CS/pTa和PEEK/CS笼子的生物安全性。结果 X 射线和 MRI 成像表明 PEEK/CS/pTa 笼和 PEEK/CS 笼均保持相似的平均椎间隙高度。术后 26 周，两组融合器的融合区组织体积具有可比性。组织学形态学​​数据显示，PEEK/CS/pTa 笼和带有自体骨移植物的 PEEK/CS 笼在 12 周和 26 周时具有相似的骨接触和骨整合。血清、尿液、脊髓、硬脑膜物质、骨骼和器官的元素测定表明，CS/PEEK笼子在植入后没有引起山羊局部组织和主要器官中钙和硅的异常全身代谢或积聚。心、肝、脾、肝、肾组织未见明显病理改变。结论 总体而言，这些结果表明，无移植物 PEEK/CS/pTa 融合器显示出与具有自体骨移植物的 PEEK/CS 融合器相似的骨融合性能。释放钙和硅的笼子在体内具有良好的生物安全性。本文的转化潜力：这项研究为退行性椎间盘疾病患者提供了一种新的无移植物椎间融合解决方案，可以避免潜在的供体部位并发症。本研究还对体内元素排泄和钙、硅的积累进行了详细评估，验证了这种新型生物活性椎体间融合笼的生物安全性。