3D打印技术在骨科关节中的应用进展

【摘要】随着新材料技术的不断发展,3D打印技术在骨科关节领域中的应用越来越广泛。本文综述了3D打印技术在骨科关节中的研究进展,分别介绍了3D打印在解剖学教育、医生和患者及其家属的术前沟通、临床治疗方案设计的应用,并对关节置换和骨关节软骨修复在组织工程领域的进展进行了阐述。最后,对3D打印技术在该领域未来的机遇和挑战进行了预测。     

基于快速成型技术制造生物骨方法的研究

快速成型制造技术以它自由生成固体形状的特点成为骨组织工程中的研究热点之一.本文综述和分析了快速成型技术中的几种主要的制造方法,重点讨论当前国内外热点研究的应用立体光造型(stereo-lithography,SL)、选择性激光烧结(selective laser sintering,SLS)、熔化沉积制造(fusion deposition modeling,FDM)和三维印制(three-dimensional plotting/printing,3DP)等快速成型方法制造生物仿生骨的情况,并且归纳国内外最新的研究方向和成果.     

光辅助X射线体表定位在骨科植入物内固定中的应用

背景：以往骨科内固定常使用C臂机进行体表定位,但固定中的反复透视会加大对人体的损伤及延长固定时间。 目的：探寻一种简便实用、更有利于骨科内固定的光辅助X射线体表定位技术。 方法：使用自制的简易装置将雷达状的红色激光投射在体表来辅助C臂机进行体表定位。使用SD大鼠和新西兰大白兔设计动物实验,模拟软组织内异物定位、骨折髓内钉远端锁钉置入、脊柱椎弓根螺钉进针点定位3种骨科内固定方法。分别使用传统C臂机和光辅助X射线体表定位技术各进行 30次定位。分析2种方法对操作的影响,并分析深度和活体因素对光辅助X射线体表定位技术的影响。 结果与结论：与传统C臂机定位相比,光辅助X射线体表定位技术在实验过程中能够更快的进行体表定位(P < 0.05),但定位的深度和活体因素会影响光辅助X射线体表定位技术的准确度(P < 0.05)。说明光辅助X射线体表定位技术具有简便、快速、动态化的优点,可方便骨科内固定的进行,但在固定过程中需考虑各种因素对定位准确性的影响,减小或消除这些影响因素将更好的发挥光辅助X射线体表定位技术的优势。     

3D打印技术在骨科的应用研究

3D打印呈现井喷式的发展,该技术在骨科的应用是一个热门的研究方向。本文阐述了3D打印技术在骨科方面的应用近况,主要对该技术在术前规划、术中导航、临床教学、医患沟通、康复支具、骨科内植物、生物打印等多个方面的应用进行综述,归纳了3D打印技术运用于骨科的优势,总结了目前存在的一些技术难点,并对3D打印技术在大块骨缺损的修复、假肢等方面的应用进行了展望。     

颈椎单开门椎管扩大成形：植入物与植骨及并发症

背景：颈椎单开门椎管扩大成形技术应用于临床治疗颈椎病已取得确切疗效。目的：从颈椎单开门椎管扩大成形技术的术式演变、各术式的优缺点及临床常见并发症3个方面对此术式治疗颈椎病的疗效做一简要阐述。方法：以“单开门,椎管扩大成形术,适应证,术后并发症”,“unilateral open-door,expansive laminoplasty,indications,postoperative complications”为检索词,应用计算机检索维普期刊全文数据库及Pubmed数据库,保留65篇文献做进一步分析。结果与结论：颈椎单开门椎管扩大成形技术应用于多节段脊髓型颈椎病、颈椎后纵韧带骨化症、无骨折脱位型脊髓损伤伴颈椎椎管狭窄等疾病疗效肯定,临床医师应该慎重地选择术式和有意识预防并发症的发生。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

快速成型技术在人工骨制造过程中的应用研究

通过对快速成型技术原理的介绍和对国内外 RP 技术在人工骨制造过程中的研究现状及实际应用的描述。探讨快速成型技术(RP)在人工骨制造领域的应用价值。提出了此研究领域存在的问题和发展方向。证明快速成型技术在人工骨制造领域具有很好发展前景。     

快速成型技术在骨科的应用研究进展

快速成型技术是20世纪80年代中期发展起来的,它是在计算机控制下,根据物体的CAD模型或CT等数据,不借助其他设备,通过材料的精确堆积,制造原型的一种基于离散、堆积成型原理的新的数字化成型技术;近年来通过与螺旋CT或核磁共振等检测手段的三维图像重建功能相结合,在骨科领域显示出良好的应用前景。综述了该技术在骨科领域内的器官模型制备和手术策划、个体化假体制备、骨组织工程多孔支架制备等主要应用方向的研究进展。     

快速成型技术在正颌外科中的应用

目的利用螺旋CT扫描、三维重建和快速成型技术制作三维头颅模型,并探讨其在口腔颌面部治疗中应用的可行性与准确性。方法对1例颅骨和口腔颌面部不对称严重畸形的第一、二鳃弓综合症患者使用螺旋CT连续薄层容积扫描,CT数据传至工作站后行三维重建并转换成STL文件格式。将处理后的数据输入快速成型机制造三维头颅模型,在此模型上直接进行测量,并利用患者健侧下颌骨镜像复制出其患侧下颌。结果根据CT数据制作的三维模型能立体、精确地显示颅面三维解剖结构及其相互关系。模型与真实个体之间总体误差可以控制在0．02～0．53mm。通过镜像复制出患侧下颌骨模型。为准确了解畸形情况、制定合理的手术治疗计划提供了极为重要的依据。结论快速成型技术制作颅骨镜像实体模型可行。     

快速成型技术在医学中的应用

快速成型是 2 0世纪 80年代末发展起来的新技术 ,它在医学上已得到广泛应用。本文对快速成型进行了简单介绍 ,主要综述了在手术计划、假体制造和生物工程中的应用 ;对某些领域中的不足也进行了讨论 ,主要是相对于工业快速成型技术可达到的精度 ,医学 CT扫描的层距显得过厚。     

3D打印技术在创伤骨科中的应用进展

随着3D打印技术的不断发展,其在创伤骨科领域中的应用越来越广泛,几乎涵盖了人体所有的解剖区域。3D打印技术也被称为"增材制造技术"和"快速成形技术",被认为是"第二次工业革命"。3D打印技术不仅可以打印出患者特异性的解剖实体模型,便于医师对患者复杂的解剖结构及疾病有更好的理解,同时有助于医学教育和手术培训,而且对于一些特殊患者可以制造定制的植入导板及假体,匹配患者的解剖结构,有效解决临床治疗难题。本文就3D打印技术在创伤骨科中的应用进展进行综述。     

快速成型技术原理及其医学应用

随着社会需要和科学技术的发展,产品更新的周期越来越短,因而要求设计者不但能根据市场的要求很快地设计新产品,而且能在尽可能短的时间内制造出产品,进行必要的性能测试,征求用户的意见,并进行修改,最后形成能投放市场的定型产品.     

In vitro dermal and epidermal cellular response to titanium alloy implants fabricated with electron beam melting

Transdermal osseointegrated prostheses (TOPs) are emerging as an alternative to socket prostheses. Electron beam melting (EBM) is a promising additive manufacturing technology for manufacture of custom, freeform titanium alloy (Ti6Al4V) implants. Skin ongrowth for infection resistance and mechanical stability are critically important to the success of TOP, which can be influenced by material composition and surface characteristics.We assessed viability and proliferation of normal human epidermal keratinocytes (NHEK) and normal human dermal fibroblasts (NHDF) on several Ti6Al4V surfaces: solid polished commercial, solid polished EBM, solid unpolished EBM and porous unpolished EBM. Cell proliferation was evaluated at days 2 and 7 using alamarBlue^® and cell viability was analyzed with a fluorescence-based live–dead assay after 1 week.NHDF and NHEK were viable and proliferated on all Ti6Al4V surfaces. NHDF proliferation was highest on commercial and EBM polished surfaces. NHEK was highest on commercial polished surfaces.All EBM Ti6Al4V discs exhibited an acceptable biocompatibility profile compared to solid Ti6Al4V discs from a commercial source for dermal and epidermal cells. EBM may be considered as an option for fabrication of custom transdermal implants.     

Bone growth in rapid prototyped porous titanium implants

Two porous titanium implants with a pore size diameter of 800 and 1200 microm (Ti800 and Ti1200) and an interconnected network were manufactured using rapid prototyping. Their dimensions and structure matched those of the computer assisted design. The porosity of the implants was around 60%. Their compressive strength and Young's modulus were around 80 MPa and 2.7 GPa, respectively. These values are comparable to those of cortical bone. The implants were implanted bilaterally in the femoral epiphysis of 15 New Zealand White rabbits. After 3 and 8 weeks, abundant bone formation was found inside the rapid prototyped porous titanium implants. For the Ti1200 implants, bone ingrowth was (23.9 +/- 3.5)% and (10.3 +/- 2.8)%, respectively. A significant statistical difference (p < 0.05) was found for bone ingrowth in the Ti1200 between the two delays. The percentage of bone directly apposited on titanium was (35.8 +/- 5.4)% and (30.5 +/- 5.0)%. No significant difference was found for bone-implant contact between the different time periods and pore sizes. This work demonstrates that manufacturing macroporous titanium implants with controlled shape and porosity using a rapid prototyping method is possible and that this technique is a good candidate for orthopedic and maxillofacial applications.     

Microstructure and mechanical properties of open-cellular biomaterials prototypes for total knee replacement implants fabricated by electron beam melting

Total knee replacement implants consisting of a Co–29Cr–6Mo alloy femoral component and a Ti–6Al–4V tibial component are the basis for the additive manufacturing of novel solid, mesh, and foam monoliths using electron beam melting (EBM). Ti–6Al–4V solid prototype microstructures were primarily α-phase acicular platelets while the mesh and foam structures were characterized by α^′-martensite with some residual α. The Co–29Cr–6Mo containing 0.22% C formed columnar (directional) Cr₂₃C₆ carbides spaced ∼2 μm in the build direction, while HIP-annealed Co–Cr alloy exhibited an intrinsic stacking fault microstructure. A log–log plot of relative stiffness versus relative density for Ti–6Al–4V and Co–29Cr–6Mo open-cellular mesh and foams resulted in a fitted line with a nearly ideal slope, n=2.1. A stress shielding design graph constructed from these data permitted mesh and foam implant prototypes to be fabricated for compatible bone stiffness.     

快速成型聚乳酸-聚羟乙酸/磷酸三钙支架修复兔桡骨缺损

背景：理想的骨修复材料除必须具有生物相容性、可吸收性、利于血管化及迅速被新生组织替代的孔隙率,还需要有与骨组织相似三维结构。 目的：检验快速成型工艺制作的聚乳酸-聚羟乙酸/磷酸三钙支架复合骨形态发生蛋白修复兔桡骨缺损的效果。 方法：将乳酸乙醇酸共聚物溶于1,4-二氧六环中并混合粉末状磷酸三钙制备成液态的浆料,放入生物材料快速成形机TissFormTM制备出直径5 mm,长15 mm的圆柱形人工骨载体材料。按每个材料15 mg的标准,采用预湿、负压复合骨形态发生蛋白、冻干3步处理,制备出活性人工骨材料。健康新西兰大白兔20只,制备右前肢桡骨中上段15 mm骨缺损模型,实验组和对照组分别植入复合骨形态发生蛋白的活性人工骨和未复合骨形态发生蛋白的单纯支架。通过影像学、组织学、材料降解及骨密度评价修复兔桡骨缺损的效果。 结果与结论：12周时实验组骨缺损愈合,新生骨痂连接缺损断端并塑形,支架材料近于完全降解,各检测指标与对照组比较差异均有显著性意义,对照组骨缺损内未见新骨形成。结果表明复合骨形态发生蛋白的聚乳酸-聚羟乙酸/磷酸三钙支架可以很好的修复兔15 mm骨缺损,且降解速度与成骨速度匹配良好。     

Cellular Ti-6Al-4V structures with interconnected macro porosity for bone implants fabricated by selective electron beam melting

Selective electron beam melting (SEBM) was successfully used to fabricate novel cellular Ti-6Al-4V structures for orthopaedic applications. Micro computer tomography (muCT) analysis demonstrated the capability to fabricate three-dimensional structures with an interconnected porosity and pore sizes suitable for tissue ingrowth and vascularization. Mechanical properties, such as compressive strength and elastic modulus, of the tested structures were similar to those of human bone. Thus, stress-shielding effects after implantation might be avoided due to a reduced stiffness mismatch between implant and bone. A chemical surface modification using HCl and NaOH induced apatite formation during in vitro bioactivity tests in simulated body fluid under dynamic conditions. The modified bioactive surface is expected to enhance the fixation of the implant in the surrounding bone as well as to improve its long-term stability.     

The concept of protection potential applied to the corrosion of metallic orthopedic implants.

Cyclic polarization curves obtained for a cobalt-base casting alloy (similar to Vitallium Surgical Alloy) and for 316L stainless steel show that the cobalt-base alloy exhibits a high (noble) protection potential whereas the stainless steel exhibits a low (active) protection potential. It is suggested that the resistance to crevice corrosion of Vitallium Surgical Alloy results from its high value of protection potential whereas the susceptibility of 316L stainless to severe crevice corrosion results from its low value of protection potential.     

应用三维成像和快速成型技术构建犬下颌髁突模型

背景：颅颌面骨为不规则骨,具有复杂的三维立体结构。对于颅颌面的骨缺损,进行个性化精确修复十分重要。计算机辅助设计、计算机辅助制造和激光扫描技术是近年发展起来的高新技术,通过这些技术可以实现颅颌面个性化骨形态结构的三维仿真。 目的：设计一个由计算机辅助设计、计算机辅助制造和激光扫描技术组成的数字医学系统,以实现生物材料对下颌骨髁突等形态的三维模拟。 方法：通过CT扫描获得犬头颅影像信息,计算机辅助设计、计算机辅助制造实现下颌骨形态的三维重建影像,影像数据输入三维打印机,快速成型获得下颌骨髁突的树脂阳模。阴阳模转换获得相应石膏阴模,聚羟基乙酸/聚乳酸阴模内成型,激光三维表面扫描检测聚羟基乙酸/聚乳酸支架和影像原型匹配的精确度。 结果与结论：聚羟基乙酸/聚乳酸支架和影像原型匹配的精确度检测结果显示,当测试点误差小于1.0 mm时,复合率大于95%。提示通过这套数字医学系统,可实现颅颌面骨形态结构生物材料的三维仿真,为下颌骨骨缺损的精确修复打下基础。     

Bone inductive properties of rhBMP-2 loaded porous calcium phosphate cement implants in cranial defects in rabbits

In this study, the osteoinductive properties of porous calcium phosphate (Ca-P) cement loaded with bone morphogenetic protein 2 (rhBMP-2) were evaluated and compared with rhBMP-2 loaded absorbable collagen sponge (ACS). Discs with a diameter of 8mm were loaded with a buffer solution with or without 10 microg rhBMP-2 and inserted in 8mm full thickness cranial defects in rabbits for 2 and 10 weeks of implantation. Histological analysis revealed excellent osteoconductive properties of the Ca-P material. It maintained its shape and stability during the implantation time better than the ACS but showed no degradation like the ACS. Quantification of the Ca-P cement implants showed that bone formation was increased significantly by administration of rhBMP-2 (10 weeks pore fill: 53.0+/-5.4%), and also reached a reasonable amount without rhBMP-2 (43.1+/-10.4%). Remarkably, callus-like bone formation outside the implant was observed frequently in the 2 weeks rhBMP-2 loaded Ca-P cement implants, suggesting a correlation with the presence of growth factor in the surrounding tissue. However, an additional in vitro assay revealed an accumulative release of no more than 9.7+/-0.9% after 4 weeks. We conclude that: (1). Porous Ca-P cement is an appropriate candidate scaffold material for bone engineering. (2). Bone formation can be enhanced by lyophilization of rhBMP-2 on the cement. (3). Degradation of porous Ca-P cement is species-, implantation site- and implant dimension-specific.