Advancements in Nanotechnology for Spinal Surgery: Innovations in Spinal Fixation Devices for Enhanced Biomechanical Performance and Osteointegration.

Spinal injuries have a major impact on patients' quality of life due to the implacable consequences they bring, such as reduced mobility and loss of flexibility, in most cases requiring surgery to restore spinal stability and functionality. In this respect, spinal fixation devices represent an important strategy to stabilize the spine after severe injuries or degenerative conditions, providing structural support and preserving spinal function. However, at the moment, the materials used to manufacture spinal implants present numerous disadvantages (e.g., Young's modulus larger than cortical bone, which can produce bone resorption and implant enlargement) that can lead to implant failure. In this context, nanotechnology can offer promising solutions, bringing improved properties (e.g., biocompatibility, osseointegration, and increased mechanical performance) that increase the potential for obtaining devices customized to patients' needs. Thus, the present work aims to present an overview of the types of nanocoating surface modification, the impact of rough and porous implant surfaces, and the integration of bioactive nanoparticles that reduce the risk of infection and implant rejection. In addition, incorporating 3D printing technology and the use of biodegradable materials into the discussion provides a valuable perspective for future studies in this field. Although the emerging results are encouraging, further studies to assess the long-term safety of implant coatings are needed.