The Application Of 3D Printing Technology In Bone Tissue Engineering And Clinical Practice In Children Orthopedics

Objective Using reverse engineering(RE)and rapid prototyping(RP)technology to design a new guided template.To explore the feasibility and accuracy of application of three-dimentional-printed guided template in children with pediatric orthopaedics diseases such as developmental dysplasia of the hip(DDIH),cubitus varus or femoral neck fracture.Methods Between October 2014 and September 2016,179 patients(208 operations)were included in our study.116 patients(144 hips)with DDH were studied.Of the 116 patients,21 were boys and 95 were girls;88 had unilateral DDH(left 63,right 25),and 28 had bilateral DDH.The patient's ages ranged from 1.5-12.7years(mean 3.1years).101 hips were treated with proximal femoral rotation and shortening osteotomy,39 hips with proximal femoral varus,rotation and shortening osteotomy and 4 only with proximal femoral varus osteotomy.Of these 144 hips,guided template was designed and performed for 67 DDH patients(template guided group),surgical information and outcomes were compared to 77 patients undergoing the same surgery but without using guided template(traditional operation group).28 patients(29 hips)with femoral neck fracture were studied.Of the 28 patients,13 were boys and 15 were girls;27 had unilateral fracture(left 12,right 15),and 1 had bilateral fracture.The patient's ages ranged from 4.1-13.7years(mean 8.6 years).16 hips were fixxed with cannulated screwsafter reduction and 13 hips with locking compression-pediatric hip plates(LCP-PHP).Of these 29 hips,guided template was designed and performed for 13 hips(template guided group),surgical information and outcomes were compared to 16 hips undergoing the same surgery but without using guided template(traditional operation group).35 patients with cubitus varus were studied.Of the 35 patients,21 were boys and 14 were girls;17 left and 18 right.The patient's ages ranged from 4.6-13.2years(mean 7.5 years).All patients were performed with lateral osteotomy of the distal humerus.Of these 35 cases,guided template was designed and performed for 16 cases(template guided group),surgical information and outcomes were compared to 19 cases undergoing the same surgery but without using guided template(traditional operation group).Allthe patients' CT data were measured and analyzed by computer software,individual guided templates were designed according to different surgical methods.simulation operations were performed with 3D printed model preoperative,the guided template were used to assist internal fixation and accurate osteotomy intraoperative.The operation time,X-ray exposure times,epiphyseal injury times and surgical outcomes were recorded.Results The guided templates were found to match the bone marker well.Intraoperative operation consistent w:ith preoperative measurement and simulation operation.For patients with proximal femoral rotation and shortening osteotomy,There were significantly decrease of operation time(17.09±2.87min vs.34.87±7.99min(p<0.001)in template guided group patients,For patients with proximal femoral varus,rotation and shortening osteotomy,There were also significantly decrease of operation time(22.33=15.12min vs.46.3819.25min(p<0.001)),x-ray exposure times(3.61 ±0.78 vs.6.4311.47,P<0.OO1)and femoral epiphysis damage times(0 vs.0.7110.96(p?0.003)in template guided group patients when compared with traditional operation group.After 6-12 months follow-up,template guided group achieved a better surgical outcome by McKay criteria and Severin criteria,however,there was no significant difference p>0.05).For femoral neck fracture patients,Two to three screws were accurately inserted in the femoral neck,and the end of the fracture was successfully stabilized.Implantation of the cannulated screws or LCP-PHP took an average of 13.57 and 25.17 min,respectively,whereas intraoperative X-ray was used an average of 3.29 times for the former and 5.17 times for the latter.No femoral ephysis injured.This was compared to 39.0 and 57.57 min(p<0.001),7.78 and 11.29 X-rays(p<0.001),2.33 and 4.19 ephysis injuries(p<0.001).6?12 monthfollow-ups indicated that there was no significant difference of surgical outcomes between two groups by Ratliff's criteria.For patients with cubitus varus.There were significantly decrease of operation time(11.69±2.21min vs.22.89±3.94min,p<0.001)in template guided group patients.When we compared postoperative carrying angle differences between affected side and the healthy side,There were significantly decrease of template guided group patients(1.13±1.20°vs.4.212.27°,p<0.001).3-6 month follow-ups indicated that there was no significant difference of surgical outcomes between two groups by Bellemore criteria.Conclusion Application of guided template for pediatric othopaedics surgeries can reduce operation time,radiation exposure,and epiphysis damage which also simplify surgery and improve precision for better outcomes.It is worth popularizing and applying.ObjectiveTo create a three-dimensional printed(3DP)Ti-6Aluminum-4Vanadium(Ti-6Al-4V)porous scaffold with rougher surface and larger pore size via lower power selective laser melting(SLM)process and compare its mechanicaland biological properties with products by electron beam melting(EBM)process.Methods Porous 3D Ti-6Al-4Vscaffolds were designed by computer and fabricated via SLM and EBM process.Microstructure morphology observation was performed by scanning electron microscopy(SEM),Mental component composition of scaffold was measured using inductively coupled plasma-atomic emission spectrometer(ICP-AES),mechanicaland biological properties of scaffolds fabricated via SLM and EBM were also compared.Results SLM fabricated scaffolds(SFS)could match the designed values more accurately than EBM fabricated scaffolds(EFS)with pore size difference(33±20?m vs81 ±37 ?m,P<0.05)and fiber diameter difference(28±10?m vs87±38 ?m,P<0.05).EFS has a lower oxygen element than SFS(P<0.05).SFS got a rougher surface than EFS.SFS with slim fiber and large pore size had a lower elasticity modulus(P<0.05)but also lower bearing force(P<0.05)than EFS.Cell proliferation was significantly greater in SFS compared to EFS at 1,7,14 and 28 days,however,the rate of live cells(RLC)showed no significantly difference between SFS and EFS.Conclusion 3DP Ti-6A1-4V scaffold fabricated by lower power SLM process possess rougher surface and larger pore size which result lower elasticity modulus and greater biological activity but lower bearing force than scaffold fabricated via EBM process.And it is more suitable for bone defect repair at low compression part.