Spinal fusion cages are commonly used to treat spinal diseases caused by degenerative changes, deformities, and trauma. At present, most of the main clinical spinal fusion cage products are non-degradable and still cause some undesirable side effects, such as the stress shielding phenomenon, interference with postoperative medical imaging, and obvious foreign body sensation in patients. Degradable spinal fusion cages have promising potential with extensive perspectives. The purpose of this study was to fabricate a degradable spinal fusion cage from both polycaprolactone (PCL) and high-proportion beta-tricalcium phosphate (β-TCP), using the highly personalised, accurate, and rapid fused deposition modelling 3 D printing technology. PCL and β-TCP were mixed in three different ratios (60:40, 55:45, and 50:50). Both in vitro degradation and cell experiments proved that all cages with the different PCL:β-TCP ratios met the mechanical properties of human cancellous bone while maintaining their structural integrity. The biological activity of the cages improved with higher amounts of the β-TCP content. This study also showed that a spinal fusion cage with high β-TCP content and suitable mechanical properties can be manufactured using extruding rods and appropriate models, providing a new solution for the design of degradable spinal fusion cages.

脊柱融合器通常用于治疗由退行性变化、畸形和外伤引起的脊柱疾病。目前，临床上主要的脊柱融合器产品大多是不可降解的，仍然存在一些不良副作用，如应力屏蔽现象、对术后医学影像的干扰、患者有明显的异物感等。可降解脊柱融合器具有广阔的前景。本研究的目的是使用高度个性化、准确和快速的融合沉积建模 3D 打印技术，用聚己内酯 (PCL) 和高比例 β-磷酸三钙 (β-TCP) 制造可降解脊柱融合器。PCL 和 β-TCP 以三种不同的比例（60:40、55:45 和 50:50）混合。体外降解和细胞实验都证明，具有不同 PCL:β-TCP 比例的所有保持架均符合人体松质骨的力学性能，同时保持其结构完整性。笼子的生物活性随着β-TCP含量的增加而提高。该研究还表明，使用挤压棒和合适的模型可以制造出具有高β-TCP含量和合适力学性能的脊柱融合器，为可降解脊柱融合器的设计提供了新的解决方案。