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上颈椎畸形伴寰枢关节脱位或不稳常导致脊髓压迫,严重影响病人的生活质量。目前脊柱外科治疗这种颅颈交界区疾病的标准术式是后路枕颈融合术,但传统枕颈融合的内植物存在置钉困难、缺乏良好解剖形态匹配、无孔隙结构等缺陷,无法直接骨长入,只能进行植骨融合,存在融合失败的风险[1]。有学者发现多孔结构对骨长入有积极的促进作用,并利用3D打印技术设计制造多孔植入物来解决骨长入问题[2-3]。我院脊柱外科团队利用3D打印等数字医学技术,研制出一款集固定、置钉、融合为一体的3D打印个体化枕颈融合器(专利号:ZL201721220260.5),并将其骨接触面设计为仿骨小梁的多孔结构。但这种多孔结构与颅骨、颈椎后弓表面皮质骨能否像3D打印多孔髋臼杯一样获得良好骨长入,尚未见相关报道。为此,我们利用兔长骨皮质骨模拟颅骨与颈椎后弓皮质骨进行实验,旨在探讨3D打印多孔钛板能否与处理后的皮质骨表面形成有效骨长入从而获得融合,并确定适宜骨长入的孔隙率,为3D打印枕颈融合器在骨性融合方面提供理论支持。现作报道。
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各标本植入的多孔钛板均固定在位,未见明显移位现象。术后4周,各组标本钛板周围及与骨面间可见纤维组织,未见明显骨痂形成。术后16周,各组标本钛板和骨面之间有新生骨组织形成连接,钛板周围有较多的骨痂形成,个别钛板被骨痂包裹(见图 3)。
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X线片观察显示,各组钛板均固定在位。术后4周多孔钛板与骨质之间无明显骨痂形成,部分钛板与骨面之间存在有一定间隙。术后16周钛板周围均有不同程度的骨痂形成,部分钛板被骨痂包绕,钛板与骨面结合紧密,未见明显间隙(见图 4)。
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术后16周,A组实验兔钛板边缘可见骨组织长入,但由于孔隙率过低,各孔隙之间空间较小,孔隙内部骨长入欠佳;B组可见一定量的新骨生成并长入孔隙之中,但骨组织与钛板之间存在一定缝隙,骨-植入物界面骨结合不良,易发生微动影响远期稳定性;C组钛板孔隙间空间适宜,各孔隙互有联通,新生骨组织长入孔隙内部,长入密度较高,且与钛板结合紧密(见图 5)。3组新生骨形成率间差异有统计学意义(P<0.01),其中C组均明显高于A组和B组(P<0.01),B组亦明显高于A组(P<0.01)(见表 1)。
分组 新生骨形成率/% F P MS组内 A组 13.69±1.86 B组 22.87±2.99** 79.40 <0.01 10.383 C组 36.96±4.33**## q检验:与A组比较**P<0.01;与B组比较##P<0.01 表 1 3组实验兔术后16周新生骨形成率比较(x±s)
3D打印多孔钛金属植入物不同孔隙率对骨长入影响的实验研究
Study on the effect of different porosity of 3D printing porous titanium implants on bone ingrowth
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摘要:
目的通过动物实验探讨3D打印多孔钛金属植入物不同孔隙率对骨长入的影响。 方法18只健康新西兰兔随机分为A、B、C组,各6只。利用3D打印技术制备3种孔隙率的多孔钛板:A组35%,B组55%,C组75%,分别将多孔钛板植入兔股骨干置板区域。于术后第4、16周取股骨干标本进行X线片、大体观察和组织学观察,比较3组新生骨形成率。 结果术后4周,各组钛板周围及与骨面间可见纤维组织,未见明显骨痂形成,X线片见部分钛板与骨面有间隙;术后16周,各组钛板周围及与骨面之间有新骨形成连接,个别钛板被骨痂包裹,X线片见钛板与骨面贴合紧密。组织学观察:A组钛板边缘有新骨生成,但中间孔隙内仅有少量骨组织长入;B组钛板孔隙内部分骨组织长入,但与钛板之间存在一定缝隙;C组钛板孔隙间新骨长入密度较高,且与钛板结合紧密。3组新生骨形成率差异有统计学意义(P < 0.01),A组均明显低于B、C组(P < 0.01),B组亦明显低于C组(P < 0.01)。 结论3D打印多孔钛板的孔隙结构,可以允许新生骨长入;不同孔隙率影响3D打印钛金属植入物的新生骨长入效果,75%孔隙率较35%、55%更有利于骨长入,可与经适当处理的皮质骨表面实现良好的骨性融合。 Abstract:ObjectiveTo investigate the effects of different porosity of 3D printing porous titanium implants on bone ingrowth through animal experiments. MethodsEighteen healthy New Zealand rabbits were randomly divided into A, B and C groups.Three kinds of porosity porous titanium plates in A, B and C groups prepared by 3D printing technology were 35%, 55% and 75%, respectively.The titanium plate was implanted into the femoral shaft plate area of rabbits.After 4 weeks and 16 weeks of operation, the femoral shaft specimens were examined using X-ray, and the gross and histological observation in bone tissue section were implemented.The rates of new bone formation in three groups were compared. ResultsAfter 4 weeks of operation, the fibrous tissue was found around the titanium plate and between titanium plate and bone surface, and no obvious callus formation was observed in each group.The results of X-ray films showed that some gaps were identified between titanium plate and the bone surface.After 16 weeks of operation, there were new bone connections around titanium plate and between titanium plate and bone surface in each group, a few titanium plates were wrapped by bone scabs, and the results of X-ray films showed that the titanium plate was closely attached to the bone surface.The results of histological observation showed that some new bone formation could be seen at the edge of titanium plate, but only a small amount of bone tissue grew into the middle pore in group A; In group B, some bone tissue grew into the pores, but there was a certain gap between pores and titanium plate; In group C, the density of new bone between pores of titanium plate was higher, and it was closely bound to titanium plate.The differences of the rates of new bone formation among three groups were statistically significant(P < 0.01), the rate of new bone formation in group A was significantly lower that in B and C groups(P < 0.01), and the rate of new bone formation in group B was significantly lower that in group C(P < 0.01). ConclusionsThe pore structure of 3D printing porous titanium plate can allow new bone to grow in.Different porosities affect the effect of new bone ingrowth of 3D printed titanium implants The 75% porosity is more beneficial to bone ingrowth compared with 35% and 55% porosity.The printing porous titanium plates can achieve good bone fusion with proper treating cortical bone surface. -
Key words:
- 3D printing /
- porous titanium implant /
- porosity /
- bone ingrowth
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表 1 3组实验兔术后16周新生骨形成率比较(x±s)
分组 新生骨形成率/% F P MS组内 A组 13.69±1.86 B组 22.87±2.99** 79.40 <0.01 10.383 C组 36.96±4.33**## q检验:与A组比较**P<0.01;与B组比较##P<0.01 -
[1] 臧全金, 历强, 梁辉, 等.寰枢椎脱位手术后翻修的原因及策略[J].中国脊柱脊髓杂志, 2017, 27(3):220. doi: 10.3969/j.issn.1004-406X.2017.03.05 [2] BANERJEE S, ISSA K, KAPADIA BH, et al.Systematic review on outcomes of acetabular revisions with highly-porous metals[J].Int Orthop, 2014, 38(4):689. doi: 10.1007/s00264-013-2145-5 [3] XU N, WEI F, LIU X, et al.Reconstruction of the upper cervical spine using a personalized 3D-printed vertebral body in an adolescent with ewing sarcoma[J].Spine(Phila Pa 1976), 2016, 41(1):E50. doi: 10.1097/BRS.0000000000001179 [4] 刘永庆, 李琪佳, 崔逸爽, 等.多孔金属骨科内植物的研究进展[J].中国老年学杂志, 2017, 37(12):3080. doi: 10.3969/j.issn.1005-9202.2017.12.102 [5] SUR S, NEWCOMB CJ, WEBBER MJ, et al.Tuning supramolecular mechanics to guide neuron development[J].Biomaterials, 2013, 34(20):4749. doi: 10.1016/j.biomaterials.2013.03.025 [6] ARABNEJAD S, BURNETT JR, PURA JA, et al.High-strength porous biomaterials for bone replacement:A strategy to assess the interplay between cell morphology, mechanical properties, bone ingrowth and manufacturing constraints[J].Acta Biomater, 2016, 30(8):345. [7] WANG X, XU S, ZHOU S, et al.Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants:A review[J].Biomaterials, 2016, 83(3):127. [8] CHIKARAKARA E, FITZPATRICK P, MOORE E, et al.In vitro fibroblast and pre-osteoblastic cellular responses on laser surface modified Ti-6Al-4V[J].Biomed Mater, 2014, 10(1):015007. doi: 10.1088/1748-6041/10/1/015007 [9] YANG J, CAI H, LV J, et al.In vivo study of a self-stabilizing artificial vertebral body fabricated by electron beam melting[J].Spine(Phila Pa 1976), 2014, 39(8):E486. doi: 10.1097/BRS.0000000000000211 [10] ARANDA JL, JIMéNEZ MF, RODRíGUEZ M, et al.Tridimensional titanium-printed custom-made prosthesis for sternocostal reconstruction[J].Eur J Cardiothorac Surg, 2015, 48(4):e92. doi: 10.1093/ejcts/ezv265 [11] PULEO DA, NANCI A.Understanding and controlling the bone-implant interface[J].Biomaterials, 1999, 20(23/24):2311. [12] DOIK, OUE H, MORITA K, et al.Development of implant/interconnected porous hydroxyapatite complex as new concept graft material[J].PLoS One, 2012, 7(11):e49051. doi: 10.1371/journal.pone.0049051 [13] CHENG A, HUMAYUN A, COHEN DJ, et al.Additively manufactured 3D porous Ti-6Al-4V constructs mimic trabecular bone structure and regulate osteoblast proliferation, differentiation and local factor production in a porosity and surface roughness dependent manner[J].Biofabrication, 2014, 6(4):045007. doi: 10.1088/1758-5082/6/4/045007 [14] 王雷, 李强.不同孔隙率多孔钛铌合金的生物力学强度及细胞生物相容性[J].中国组织工程研究, 2016, 20(38):5709. doi: 10.3969/j.issn.2095-4344.2016.38.013 [15] COOK SD, BARRACK RL, THOMAS KA, et al.Quantitative analysis of tissue growth into human porous total hip components[J].J Arthroplasty, 1988, 3(3):249. doi: 10.1016/S0883-5403(88)80023-8 [16] LV J, JIA Z, LI J, et al.Electron beam melting fabrication of porous Ti6A14Vscaffolds:cytocompatibility and osteogenesis[J].Adv Eng Mater, 2015, 17(9):1391. doi: 10.1002/adem.v17.9 [17] 周鹏, 赵辉, 吴宇黎, 等.钛合金假体表面涂层微孔孔径和孔隙率对骨整合的影响[J].山东医药, 2017, 57(16):12. doi: 10.3969/j.issn.1002-266X.2017.16.004 [18] KUJALA S, RYHÄNEN J, DANILOV A, et al.Effect of porosity on the osteointegration and bone ingrowth of a weight-bearing nickel-titanium bone graft substitute[J].Biomaterials, 2003, 24(25):4691. doi: 10.1016/S0142-9612(03)00359-4