Background

Boron nitride is a biocompatible and an osteo-inductive material for orthopedic applications. The aim of this study was to evaluate the effects of two different allotrope boron nitride coated implants, cubic boron nitride and hexagonal boron nitride, on fracture healing.

Methods

In this experimental study, a total of 24 rats were divided into three groups. Group A was the control group with Kirschner wire without coating, while the wires were coated dominantly by cubic boron nitride in Group B and hexagonal boron nitride in Group C. Then a mid-third femoral fracture was created. The fracture healing was examined in terms of new bone formation with micro-CT analysis and histopathological examination, quantitative measurement of bone turnover metabolites and scintigraphic examination of osteoblastic activity on 28th day post fracture.

Results

Micro-CT measurement results revealed a statistically significant increase in bone volume/tissue volume ratio and bone surface values in group B compared to group A. Cortex diameter and osteoblast counts were statistically higher in group B compared to group A. Inflammatory response was increased in group C compared to groups A and B. Biochemical test results showed significantly increased alkaline phosphatase levels and decreased osteocalcin levels in group B compared to group A. The increase in serum phosphorus and decrease in serum calcium levels was statistically significant in group C compared to Group A.

Conclusion

Both types of boron nitride coating had superior fracture healing features compared to control group. Therefore, c-BN coating can accelerate the fracture healing and could lead to shorten of union time.

中文翻译：

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涂有立方氮化硼的髓内植入物可增强大鼠模型中的骨折愈合。

背景

氮化硼是一种生物相容的骨诱导材料，用于骨科应用。本研究的目的是评估两种不同的同素异形体氮化硼涂层植入物，立方氮化硼和六方氮化硼对骨折愈合的影响。

方法

在这项实验研究中，总共有 24 只大鼠被分为三组。A组为对照组，克氏针无涂层，B组以立方氮化硼涂层为主，C组以六方氮化硼涂层为主。然后造成股骨中段骨折。在骨折后第 28 天，通过显微 CT 分析和组织病理学检查、骨转换代谢物的定量测量和成骨细胞活性的闪烁扫描检查，检查骨折愈合情况。

结果

Micro-CT 测量结果显示，与 A 组相比，B 组的骨体积/组织体积比和骨表面值有统计学意义的增加。与 A 组相比，B 组的皮质直​​径和成骨细胞计数在统计学上更高。炎症反应增加C组与A、B组比较。生化检查结果显示B组碱性磷酸酶水平明显升高，骨钙素水平明显低于A组。C组血清磷升高，血清钙水平降低，与A组比较有统计学意义一种。

结论

与对照组相比，两种类型的氮化硼涂层都具有优越的骨折愈合特性。因此，c-BN涂层可以加速骨折愈合并缩短结合时间。