Nano-hydroxyapatite coated biphasic calcium phosphate for posterolateral lumbar fusion: combined magnetic field plays an auxiliary role

doi:10.3969/j.issn.2095-4344.2016.34.012

Abstract

Abstract:

BACKGROUND: Autologous bone is considered the main material for spinal fusion, while synthetic materials overcome the shortcomings caused by the autologous bone (complications and limited source) and become the most promising bone graft substitute materials.
OBJECTIVE: To investigate the effects of nano-hydroxyapatite (nano-HA) coating and combined magnetic field (CMF) on the biphasic calcium phosphate (BCP) transplantation for rabbit posterolateral lumbar fusion.
METHODS: Forty-eight rabbits underwent bilateral intertransverse processes fusion at the level of L5-6, and were then randomly divided into six groups: rabbits in group G1 received autologous iliac bone graft and CMF treatment; group G2 was given nano-HA/BCP and CMF treatment; group G3 received BCP and CMF treatment; group G4 received autologous iliac bone graft and placebo; group G5 underwent nano-HA/BCP and placebo; group G6 received BCP and placebo. CMF treatment was performed 30 minutes each day for 8 consecutive weeks beginning at 1 week after surgery. These rabbits were euthanized at 9 weeks after surgery to evaluate spinal fusion effects through palpation, X-ray examination, CT examination, histological analysis (decalcified and undecalcified sections) and biomechanical assessment.
RESULTS AND CONCLUSION: The palpation, X-ray and histological examinations showed that there was significant difference in the fusion rate between groups G2 and G6, the highest in the group G2, and the lowest in the group G6 (P < 0.05). The bone ingrowth rate in the group G2 was significantly higher than those in the groups G3, G4 and G6 (P < 0.05). The normalized optical density index of fusion mass and bending stiffness in the group G2 were significantly higher than those in the other groups (P < 0.05). CT and histological observations found that new bone trabecula grew into the biological scaffold, exhibiting osseointegration. Factorial analysis showed that CMF and nano-HA coating could significantly improve the spinal fusion rate, fusion score, bone ingrowth rate and bending stiffness (P < 0.05). In conclusion, CMF combined with nano-HA/BCP for rabbit posterolateral lumbar fusion can significantly ameliorate the fusion rate, which is analogous to the single autologous bone; therefore, it can be used as a new spinal fusion method.

中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

Key words: Lumbar Vertebrae, Spinal Fusion, Nanocomposites, Hydroxyapatites, Electromagnetic Fields, Tissue Engineering

CLC Number:

R318

Zhuo Xiang-long, Lv Hong-bin, Hu Jian-zhong, Li Bing, Liu Yong, Wu Zu-tong. Nano-hydroxyapatite coated biphasic calcium phosphate for posterolateral lumbar fusion: combined magnetic field plays an auxiliary role[J]. Chinese Journal of Tissue Engineering Research, 2016, 20(34): 5089-5097.

Figures/Tables 11

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