Three-dimensional-printed titanium prostheses with bone trabeculae enable mechanical-biological reconstruction after resection of bone tumours

Reconstruction after resection has always been an urgent problem in the treatment of bone tumours.There are many methods that can be used to reconstruct bone defects;however,there are also many complications,and it is difficult to develop a safe and effective reconstruction plan for the treatment of bone tumours.With the rapid development of digital orthopaedics,three-dimensional printing technology can solve this problem.The three-dimensional printing of personalised prostheses has many advantages.It can be used to print complex structures that are difficult to fabricate using traditional processes and overcome the problems of stress shielding and low biological activity of conventional prostheses.In this study,12 patients with bone tumours were selected as research subjects,and based on individualised reverse-engineering design technology,a three-dimensional model of each prosthesis was designed and installed using medical image data.Ti6Al4V was used as the raw material to prepare the prostheses,which were used to repair bone defects after surgical resection.The operation time was 266.43±21.08 minutes(range 180-390 minutes),and intraoperative blood loss was 857.26±84.28 mL(range 800-2500 mL).One patient had delayed wound healing after surgery,but all patients survived without local tumour recurrence,and no tumour metastasis was found.No aseptic loosening or structural fracture of the prosthesis,and no non-mechanical prosthesis failure caused by infection,tumour recurrence,or progression was observed.The Musculo-Skeletal Tumour Society(MSTS)score of limb function was 22.53±2.09(range 16-26),and ten of the 12 patients scored≥20 and were able to function normally.The results showed that three-dimensional printed prostheses with an individualised design can achieve satisfactory short-term clinical efficacy in the reconstruction of large bone defects after bone tumour resection.

Three-dimensional-printed polycaprolactone scaffolds with interconnected hollow-pipe structures for enhanced bone regeneration

Three-dimensional(3D)-printed scaffolds are widely used in tissue engineering to help regenerate critical-sized bone defects.However,conventional scaffolds possess relatively simple porous structures that limit the delivery of oxygen and nutrients to cells,leading to insufficient bone regeneration.Accordingly,in the present study,perfusable and permeable polycaprolactone scaffolds with highly interconnected hollow-pipe structures that mimic natural micro-vascular networks are prepared by an indirect onepot 3D-printing method.In vitro experiments demonstrate that hollow-pipe-structured(HPS)scaffolds promote cell attachment,proliferation,osteogenesis and angiogenesis compared to the normal non-hollow-pipe-structured scaffolds.Furthermore,in vivo studies reveal that HPS scaffolds enhance bone regeneration and vascularization in rabbit bone defects,as observed at 8 and 12weeks,respectively.Thus,the fabricated HPS scaffolds are promising candidates for the repair of critical-sized bone defects.

Stereo morphology of temporal bone and ear

Background The temporal bone has the most complicated anatomic feature among the whole human body, which always challenges otolaryngologists. This study was to study three-dimensional (3D) morphology of the temporal bone and the ear by means of a computer image processing technique, for the purpose of providing a 3D image to help in pathological, diagnostic and surgical procedures Methods Forty sets of temporal bone celloidin serial sections with reference points were prepared and the contours of selected structures and reference points were entered into a graphics programme The technique of computer-aided 3D reconstruction was applied to obtain 3D images and parameters of the temporal bones and the ears Stereo views of the ossicles (n=5), the facial nerves (n=11), the posterior tympanic sinuses (n=11), the posterior ampullary nerves (n=4), the endolymphatic ducts and sacs (n=5), and the bony and membranous labyrinth (n=1) were reconstructed Results Three-dimensional images, including the cochlea, the ossicles, the nerves, the tendons and the endolymphatic fluid system in the temporal bone, were obtained Stereo picture pairs and 3D parameters of spatial dimensions, angle and volume for these reconstructed structures were calculated The arrangement of the ossicles, spatial relationship of the bony and membranous labyrinth, the whole course of the facial nerves, the endolymphatic sac and posterior tympanic cavity were clearly observable Stereo picture pairs made the spatial relationships among the above-mentioned structures much clearer The operation of the posterior ampullary nerve transection was designed and simulated on the graphic computer based on 3D anatomic investigations Conclusion The technique of computer-aided 3D reconstruction provides a new tool to observe the morphology of the temporal bone and thus may allow design and study of new surgical approaches

3D打印解剖模型在耳鼻喉科教学的应用

目的探讨3D打印技术在耳鼻喉科临床解剖教学中的应用。方法使用Mimics软件将颞骨和鼻窦CT元数据重建成三维数字模型。根据兴趣层面将模型切割为可观察内部解剖结构的子模型。利用3D打印机制作模型,将兴趣层面的CT影像打印、裁剪并与模型贴合。最后,校验解剖模型的准确度。结果成功地制作了颞骨和鼻窦的3D数字模型和3D打印模型,同时在模型截面上复合了CT影像图片,可准确、清晰地还原显示颞骨和鼻窦的内、外部的结构。结论本方法制作的解剖模型有助于医学生学习和掌握耳鼻喉科临床解剖和影像,是传统教学方法的有益补充。

3D打印颞骨模型制备方法及其在耳科中的应用展望

颞骨是人体最复杂的骨性结构之一,内部重要的神经、血管与位听觉结构关系密切。颞骨相关的耳科及耳神经外科手术要求医生对颞骨解剖有着全面、透彻的认识以避免损伤一些精细、重要结构,如面神经、内耳、颈内动脉和听神经。长久以来,耳外科医生通过反复解剖人体尸头的颞骨来获取和提高相关的手术技能。但人体尸头来源有限,价格日益昂贵,造成尸体颞骨解剖训练越来越困难。随着3D打印技术的发展,世界各国的研究者们制造出了可用于耳科教学和手术技能训练的3D打印颞骨模型。本文就3D打印颞骨模型的制备过程、评价方法以及近年来在耳科领域的应用作一综述。

3-D颞骨模型的制作与应用

目的探讨利用粉末堆积打印技术制作的高仿真3-D颞骨模型在解剖技能训练及模拟手术中的应用。方法利用高分辨率CT获取活体颞骨断层图像(正常人2例,慢性中耳炎患者2例),数据导入Mimics软件行图像分割及颞骨三维重建,以石膏粉末为原料,利用粉末堆积快速成型技术打印出颞骨模型,重要解剖结构与组织(听骨链、面神经、位听器、炎性渗出及胆脂瘤等)以不同颜色打印,并在显微镜下进行手术演练。结果颞骨模型的硬度与人骨相近,模型表面及内部骨性标志明显,解剖精确度高,钻磨触感接近真实,满足颞骨解剖技能训练及模拟手术的要求。结论利用粉末堆积打印技术能制作出仿真度更高、更接近实际人体解剖结构的颞骨模型,帮助临床医生在术前全面了解患者的颞骨及周围组织解剖结构与病变情况,制定和优化手术方案,减少并发症。

3D打印颞骨模型在耳鼻咽喉头颈外科学教学中的应用研究

目的探究3D打印的颞骨模型技术应用于耳鼻喉科临床解剖教学中的效果。方法选取蚌埠医学院2016级临床医学本科60名学生,随机分为观察组和对照组,每组30名。观察组采用3D打印颞骨模型教学方法,对照组采用传统采用多媒体的教学方法,介绍耳解剖及鼓膜穿刺这一部分内容,在授课完毕后,进行教学综合分析。结果观察组理论知识及技能操作考核成绩均显著高于对照组(P<0.05),观察组学习兴趣、学习效率、颞骨解剖的掌握、技能操作的掌握情况均优于对照组(P<0.05)。结论3D打印颞骨模型应用于耳鼻咽喉头颈外科学的教学中,可明显提高学生对课程的兴趣和关切度,获得良好的反馈效果,同时其也是一种效率较高的教学方法,是现有教学手段的有效补充,值得推广。

Mesenchymal stem cells loaded on 3D-printed gradient poly(e-caprolactone)/methacrylated alginate composite scaffolds for cartilage tissue engineering

Cartilage has limited self-repair ability due to its avascular,alymphatic and aneural features.The combination of three-dimensional(3D)printing and tissue engineering provides an up-and-coming approach to address this issue.Here,we designed and fabricated a tri-layered(superficial layer(SL),middle layer(ML)and deep layer(DL))stratified scaffold,inspired by the architecture of collagen fibers in native cartilage tissue.The scaffold was composed of 3D printed depth-dependent gradient poly(e-caprolactone)(PCL)impregnated with methacrylated alginate(ALMA),and its morphological analysis and mechanical properties were tested.To prove the feasibility of the composite scaffolds for cartilage regeneration,the viability,proliferation,collagen deposition and chondrogenic differentiation of embedded rat bone marrow mesenchymal stem cells(BMSCs)in the scaffolds were assessed by Live/dead assay,CCK-8,DNA content,cell morphology,immunofluorescence and real-time reverse transcription polymerase chain reaction.BMSCs-loaded gradient PCL/ALMA scaffolds showed excellent cell survival,cell proliferation,cell morphology,collagen II deposition and hopeful chondrogenic differentiation compared with three individual-layer scaffolds.Hence,our study demonstrates the potential use of the gradient PCL/ALMA construct for enhanced cartilage tissue engineering.

Virtual preoperative planning and 3D printing are valuable for the management of complex orthopaedic trauma

Purpose:The technology of 3D printing(3DP)exists for quite some time,but it is still not utilized to its full potential in the field of orthopaedics and traumatology,such as underestimating its worth in virtual preoperative planning(VPP)and designing various models,templates,and jigs.It can be a significant tool in the reduction of surgical morbidity and better surgical outcome avoiding various associated complications.Methods:An observational study was done including 91 cases of complex trauma presented in our institution requiring operative fixation.Virtual preoperative planning and 3DP were used in the management of these fractures.Surgeons managing these cases were given a set of questionnaire and responses were recorded and assessed as a quantitative data.Results:In all the 91 cases,where VPP and 3DP were used,the surgeons were satisfied with the outcome which they got intraoperatively and postoperatively.Surgical time was reduced,with a better outcome.Three dimensional models of complex fracture were helpful in understanding the anatomy and sketching out the plans for optimum reduction and fixation.The average score of the questionnaire was 4.5,out of a maximum of 6,suggesting a positive role of 3DP in orthopaedics.Conclusion:3DP is useful in complex trauma management by accurate reduction and placement of implants,reduction of surgical time and with a better outcome.Although there is an initial learning curve to understand and execute the VPP and 3DP,these become easier with practice and experience.

Effects of different concentrations of TiAl6V4 particles on MC3T3-E1 cells and bone in rats

Three-dimensional(3D)-printed porous Ti6Al4V implants have good mechanical properties and excellent biocompatibility.As such,these implants are widely used in orthopedics.Particles adhere between the sintered and nonsintered interfaces of the porous samples during 3D printing.These excess particles can be cleaned by blowing the particles and via ultrasound,but the excess internal particles of complex structural parts are difficult to remove.During long-term cyclic loading,stress and strain can cause residual Ti6Al4V particles in the pores of the implant to shed.These detached Ti6Al4V particles are in extensive contact with osteoblasts and scattered around the implant.In this study,we examined the effects of different concentrations of Ti6Al4V particles on osteoblasts and bones.MC3T3-E1 cells were used to evaluate the effects of different concentrations of Ti6Al4V particles on cells after 72 h on the basis of the expression levels of genes,involving osteopontin,alkaline phosphatase,bone morphogenetic protein-2 and runt-related transcription factor-2.Microtubule-associated protein 1 light chain 3 was used to detect the autophagy of MC3T3-E1 with different concentrations of Ti6Al4V particles.The distal femoral defects of rats were examined to examine bone growth with different concentrations of Ti6Al4V particles.All rats were accepted by micro-CT and biochemical analyses after 12 weeks.The results indicated that 10 and 100μg/ml of Ti6Al4V particles may improve osteogenic differentiation.Micro-CT revealed that low concentrations of Ti6Al4V particles may improve the osteogenesis of the rats.However,the(cortical and trabecular)BMD of middle and high dose groups was no significant change compared with control group.In conclusion,low-dose residual particles do not inhibit osteoblast differentiation and do not decrease the bone mineral density of rats.

3D颞骨解剖导航模拟系统在颞骨解剖教学中的应用

目的:探索高仿真3D颞骨解剖导航模拟系统在颞骨解剖技能训练及模拟手术中的应用。方法:2014-2015年我科在耳显微外科解剖学习班中引入3D颞骨解剖导航模拟系统,每位学员通过尸头解剖及3D颞骨解剖导航模拟系统训练,进行问卷调查及操作后的评价和体会,比较传统尸头解剖与3D颞骨解剖在教学训练中的差异。结果:1在乳突轮廓化阶段3D颞骨解剖结构损伤率高于尸头解剖(33.3%>22.2%),暴露比例二者无明显差别。开放上鼓室、面神经隐窝、面神经轮廓化阶段尸头解剖损伤率及未暴露比例高于3D颞骨解剖组。2学员在解剖结构及层次、污染、味道、费用、可重复性方面二者满意度无明显差异(P>0.05),在用时、与颞骨CT可比性及关联性、相似度、力反馈方面二者满意度有明显差异(均P<0.01)。结论:3D颞骨解剖在专科医生解剖训练中有较好的应用效果,可帮助临床专科医生更好地认识和了解颞骨及周围解剖结构,加深颞骨解剖的三维立体意识。