Department of Biomedical Engineering, Faculty of Electronic Information and Electronical Engineering, Dalian University of Technology, Dalian, China.
Department of Orthopedics, Affiliated Zhongshan Hospital of Dalian University, Dalian, China.
Biomaterials. 2020 Apr;238:119829. doi: 10.1016/j.biomaterials.2020.119829. Epub 2020 Jan 30.
Magnesium (Mg)-based metals can be used as next-generation fracture internal fixation devices due to their specific properties. We used vascularized bone grafting fixed by degradable pure Mg screws and obtained satisfactory results in the treatment of osteonecrosis of the femoral head. However, the mechanical properties of these screws make them weaker than those made of traditional metals. In particular, one of the main challenges of using screws made of Mg-based metals is their application in fixation at important weight-bearing sites in the human body. Femoral neck fracture is a common clinical injury. In this injury, the large bearing stress at the junction requires a fixation device with extremely high mechanical strength. Surgery and appropriate internal fixation can accelerate the healing of femoral neck fractures. Traditional internal fixation devices have some disadvantages after surgery, including stress shielding effects and the need for secondary surgery to remove screws. On the basis of previous work, we developed high-strength pure Mg screws for femoral neck fractures. In this study, we describe the first use of high-purity Mg to prepare large-size weight-bearing screws for the fixation of femoral neck fractures in goats. We then performed a 48 weeks follow-up study using in vivo transformation experiments. The results show that these biodegradable high-purity Mg weight-bearing screws had sufficient mechanical strength and a degradation rate compatible with bone repair. Furthermore, good bone formation was achieved during the degradation process and reconstruction of the bone tissue and blood supply of the femoral head and femoral neck. This study provides a basis for future research on the clinical transformation of biodegradable high-purity Mg weight-bearing screws.
镁（Mg）基金属因其特殊性能可作为下一代骨折内固定装置。我们使用可降解纯镁螺钉固定带血管骨移植，并在治疗股骨头坏死方面取得了满意的效果。然而，这些螺钉的机械性能使它们比传统金属制成的螺钉更弱。特别是，使用基于镁的金属制成的螺钉的主要挑战之一是它们在人体重要承重部位的固定应用。股骨颈骨折是一种常见的临床损伤。在这种损伤中，交界处的大承载应力需要一种具有极高机械强度的固定装置。手术和适当的内固定可以加速股骨颈骨折的愈合。传统的内固定装置在手术后存在一些缺点，包括应力遮挡效应和需要进行二次手术取出螺钉。在先前工作的基础上，我们开发了用于股骨颈骨折的高强度纯镁螺钉。在这项研究中，我们首次描述了使用高纯镁来制备用于固定山羊股骨颈骨折的大尺寸承重螺钉。然后，我们进行了 48 周的体内转化实验随访研究。结果表明，这些可生物降解的高纯镁承重螺钉具有足够的机械强度和与骨修复相匹配的降解率。此外，在降解过程中实现了良好的骨形成，并重建了股骨头和股骨颈的骨组织和血液供应。这项研究为可生物降解的高纯镁承重螺钉的临床转化研究提供了基础。
