BACKGROUND: Nano-hydroxyapatite crystals are highly similar to human bone hydroxyapatite crystals in the shape, size, component, structure and crystallinity, and have an analogous elasticity modulus compared with human cortical bone. The application of nano-hydroxyapatite is increasingly widespread in medical field because 
of excellent osteoconduction, biocompatibility, bioactivity and high strength and toughness.
OBJECTIVE: To evaluate the primary efficacy of nano-hydroxyapatite/polyamide 66 composite bioactive artificial vertebral body for anterior column reconstruction in cervical vertebral fractures.
METHODS: A total of 78 patients with cervical vertebral fracture combined with quadriplegia admitted at the Department of Spine Surgery, the First Affiliated Hospital of Sichuan Medical University in China underwent anterior cervical corpectomy decompression, bone grafting and nano-hydroxyapatite/polyamide 66 composite bioactive artificial vertebral body fixation.
RESULTS AND CONCLUSION: The surgery was sucessful in all patients. Totally 67 patients were followed up. During the follow-up of 4-39 months, X-ray and MRI examinations showed no obvious displacement of the implants, and less loss of cervical physiological sequence and vertebral body height. The spinal function recovered to varying degrees after internal fixation. These results suggest that the application of nano-hydroxyapatite/ polyamide 66 composite bioactive artificial vertebral body in anterior cervical vertebral fractures can increase the area of bone graft fusion, decrease local intensity of pressure and prevent the loosening and sinking of the implants. The initial supporting and stability can effectively maintain cervical physiological sequence and intervertebral height. The bone graft fusion is higher after the internal fixation. It is easy for the X-ray observation, and meanwhile, there is no influence on the MRI scanning for observation of signals of the spinal cord.