BACKGROUND CONTEXT

Platelet-rich plasma (PRP) can accelerate bone union in spinal fusion surgery with an autogenous bone graft. However, it is unclear whether bone union can be obtained by using artificial bone and PRP together in spinal interbody fusion surgery.

PURPOSE

This study aimed to determine whether interbody fusion can be achieved by transplanting porous hydroxyapatite/collagen(HAp/Col) which is an artificial bone material frequently used in spinal fusion surgery, together with PRP in the intervertebral disc space in rats.

STUDY DESIGN AND SETTING

A controlled laboratory study.

METHODS

A total of fourty 10-week old Sprague-Dawley rats were used in this study and assigned to three groups as follow: disc curettage only (control group, n=10), disc curettage + HAp/Col transplant (H group, n=10), and disc curettage + HAp/Col + PRP transplant (H+P group, n=10). The other 10 rats were sacrificed as blood donors for acquisition of PRP. Microcomputed tomography (μCT) examinations were performed to evaluate bone union, bone volume (BV), and bone mineral density (BMD) at 4, 8, and 12 weeks following surgery. Twelve weeks postoperatively, each group of three of L4–L5 spines was harvested to perform histological examination (hematoxylin & eosin stain) and the others were subjected to biomechanical testing (compression properties).

RESULTS

The platelet count in PRP was approximately 4.1 times greater than that in whole blood (260.6±26.2 × 10⁴ mg/dL and 64.3±2.9 × 10⁴ mg/dL in PRP and whole blood, respectively). All the L4–L5 lumbar discs were fused in the H+P group, whereas only one case was fused in the H group and none in the control group at 12 weeks after surgery. BV was significantly higher in the H+P group than in the H group or control groups (both p<.01), although BMD was not significantly different among the three groups. Upon histological analysis, mature bone formation was observed at the transplanted space in all cases in the H+P group, whereas fibrous tissue was observed at the location in the H and control groups. Regarding biomechanical properties, the ultimate load to failure was significantly higher in the H+P group than in the H group or control group (p=.021 and .013, respectively), although stiffness was not significantly different between the three groups.

CONCLUSION

The combination of porous HAp/Col and PRP at an appropriate concentration can promote bone union in the intervertebral disc space without using an autologous bone graft in the rat model. Bone tissue formation was histologically confirmed, and it was mechanically strong.

CLINICAL SIGNIFICANCE

This preclinical study showed that porous HAp/Col, when combined with PRP at an appropriate concentration, can induce bone union without autologous bone grafts. The results may eliminate the need for autologous bone collection for spinal fusion surgery in the future.

中文翻译：

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多孔羟基磷灰石/胶原蛋白结合富血小板血浆改善 ALIF 大鼠模型的椎间骨愈合

背景语境

富含血小板的血浆 (PRP) 可以加速自体骨移植脊柱融合手术中的骨愈合。然而，在脊柱椎体间融合手术中，人工骨与PRP一起使用是否能实现骨愈合尚不清楚。

目的

本研究旨在确定是否可以通过将多孔羟基磷灰石/胶原蛋白 (HAp/Col)（一种经常用于脊柱融合手术的人造骨材料）与 PRP 一起移植到大鼠的椎间盘间隙中来实现椎间融合。

研究设计和设置

一项受控实验室研究。

方法

本研究共使用 40 只 10 周龄的 Sprague-Dawley 大鼠，分为以下三组：仅椎间盘刮除术（对照组，n=10）、椎间盘刮除术 + HAp/Col 移植（H 组，n= 10)，以及椎间盘刮除术 + HAp/Col + PRP 移植（H+P 组，n=10）。另外 10 只大鼠作为献血者被处死以获得 PRP。在手术后 4、8 和 12 周进行显微计算机断层扫描 (μCT) 检查以评估骨愈合、骨体积 (BV) 和骨矿物质密度 (BMD)。术后 12 周，收获每组三根 L4-L5 脊柱进行组织学检查（苏木精和伊红染色），其他则进行生物力学测试（压缩特性）。

结果

PRP 中的血小板计数大约是全血中的 4.1 倍（260.6±26.2 × 10 ⁴ mg/dL 和 64.3±2.9 × 10 ⁴mg/dL，分别在 PRP 和全血中）。术后12周H+P组L4~L5腰椎间盘全部融合，H组仅1例融合，对照组无融合。H+P 组的 BV 显着高于 H 组或对照组（均 p <.01），尽管 BMD 在三组之间没有显着差异。组织学分析显示，在 H+P 组的所有病例中，在移植空间均观察到成熟骨形成，而在 H 组和对照组的位置观察到纤维组织。关于生物力学特性，H+P 组的极限失效载荷明显高于 H 组或对照组（分别为 p=.021 和 .013），尽管三组之间的刚度没有显着差异。

结论

适当浓度的多孔 HAp/Col 和 PRP 的组合可以促进椎间盘间隙中的骨愈合，而无需在大鼠模型中使用自体骨移植物。骨组织形成在组织学上得到证实，并且机械强度高。

临床意义

这项临床前研究表明，当多孔 HAp/Col 与适当浓度的 PRP 结合使用时，无需自体骨移植即可诱导骨愈合。结果可能会消除未来脊柱融合手术对自体骨采集的需求。