The interventional therapy of vascular stent implantation is a popular treatment method for cardiovascular stenosis and blockage. However, traditional stent manufacturing methods such as laser cutting are complex and cannot easily manufacture complex structures such as bifurcated stents, while three-dimensional (3D) printing technology provides a new method for manufacturing stents with complex structure and personalized designs. In this paper, a cardiovascular stent was designed, and printed using selective laser melting technology and 316L stainless steel powder of 0−10 µm size. Electrolytic polishing was performed to improve the surface quality of the printed vascular stent, and the expansion behavior of the polished stent was assessed by balloon inflation. The results showed that the newly designed cardiovascular stent could be manufactured by 3D printing technology. Electrolytic polishing removed the attached powder and reduced the surface roughness Ra from 1.36 µm to 0.82 µm. The axial shortening rate of the polished bracket was 4.23% when the outside diameter was expanded from 2.42 mm to 3.63 mm under the pressure of the balloon, and the radial rebound rate was 2.48% after unloading. The radial force of polished stent was 8.32 N. The 3D printed vascular stent can remove the surface powder through electrolytic polishing to improve the surface quality, and show good dilatation performance and radial support performance, which provides a reference for the practical application of 3D printed vascular stent.
Objective To review the application progress of digital technology in auricle reconstruction. Methods The recently published literature concerning the application of digital technology in auricle reconstruction was extensively consulted, the main technology and its specific application areas were reviewed. Results Application of digital technology represented by three-dimensional (3D) data acquisition, 3D reconstruction, and 3D printing is an important developing trend of auricle reconstruction. It can precisely guide auricle reconstruction through fabricating digital ear model, auricular guide plate, and costal cartilage imaging. Conclusion Digital technology can improve effectiveness and decrease surgical trauma in auricle reconstruction. 3D bioprinting of ear cartilage future has bright prospect and needs to be further researched.
ObjectiveTo investigate the effectiveness of digital three-dimensional (3D) printing osteotomy guide plate assisted total knee arthroplasty (TKA) in treatment of knee osteoarthritis (KOA) patients with femoral internal implants. Methods The clinical data of 55 KOA patients who met the selection criteria between July 2021 and October 2023 were retrospectively analyzed. Among them, 26 cases combined with femoral implants were treated with digital 3D printing osteotomy guide plate assisted TKA (guide plate group), and 29 cases were treated with conventional TKA (control group). There was no significant difference in gender, age, body mass index, side, Kellgren-Lawrence classification, preoperative visual analogue scale (VAS) score, Hospital for Special Surgery (HSS) knee score, knee range of motion, and other baseline data between the two groups (P>0.05). The operation time, intraoperative blood loss, incision length, postoperative first ambulation time, surgical complications; VAS score, knee HSS score, knee range of motion before operation, at 1 week and 3 months after operation, and at last follow-up; distal femoral lateral angle, proximal tibial medial angle, hip-knee-ankle angle and other imaging indicators at last follow-up were recorded and compared between the two groups. ResultsThe operation time, incision length, intraoperative blood loss, and postoperative first ambulation time in the guide plate group were significantly lower than those in the control group (P<0.05). In the control group, there were 1 case of incision rupture and bleeding and 1 case of lower limb intermuscular venous thrombosis, which was cured after symptomatic treatment. There was no complication such as neurovascular injury, incision infection, or knee prosthesis loosening in both groups. Patients in both groups were followed up 12-26 months, with an average of 16.25 months. The VAS score, HSS score, and knee range of motion improved at each time point after operation in both groups, and further improved with time after operation, the differences were significant (P<0.05). The above indicators in the guide plate group were significantly better than those in the control group at 1 week and 3 months after operation (P<0.05), and there was no significant difference between the two groups at last follow-up (P>0.05). At last follow-up, the distal femoral lateral angle, the proximal tibial medial angle, and the hip-knee-ankle angle in the guide plate group were significantly better than those in the control group (P<0.05). Conclusion The application of digital 3D printing osteotomy guide plate assisted TKA in the treatment of KOA patients with femoral implants can simplify the surgical procedures, overcome limitations of conventional osteotomy guides, reduce surgical trauma, achieve individualized and precise osteotomy, and effectively restore lower limb alignment and knee joint function.
Objective To discuss the effect of three-dimensional (3D) printing individualized model and guide plate in bone tumor surgery. Methods Between October 2015 and December 2016, 3D printing individualized model and guide plate for making preoperative surgical planning and intraoperative treatment were used in 5 patients of bone tumor. All the patients were male, with a median age of 32 years (range, 9-58 years). There were 1 case of cystic echinococcosis at left pelvis and pathological fracture of the proximal femur; 1 case of left iliac bone osteoblastoma associated with aneurysmal bone cyst; 1 case of fibrous dysplasia of the left femur (sheep horn deformity) with pathological fracture; 1 case of metastatic carcinoma of right calcaneus (tumor staging was T2N0M0); and 1 case of Ewing sarcoma of left femur (tumor staging was T2N0M0). The disease duration ranged from 1 month to 10 years (mean, 2.25 years). Results The operation was completed successfully. The operation time was 2.6-7.5 hours (mean, 4.9 hours). The intraoperative blood loss was 200-2 500 mL (mean, 1 380 mL). The intraoperative fluoroscopy times was 1-6 times (mean, 3.8 times). There was no infection after operation, and the blood supply and nerve function were good. All the patients were followed up 3-16 months (mean, 5.4 months). No loosening or breaking of the internal fixator occurred. According to Enneking scoring system, the limb function score was 15-26 (mean, 21); and the results were excellent in 2 cases, good in 2 cases, and fair in 1 case. Conclusion 3D printing technology can make the implementation of the better preoperative planning and evaluation in bone tumor surgery, and it provides a new reference for individualized treatment in patients with bone tumor.
Objective To review the current research progress of three-dimensional (3-D) printing technique in foot and ankle surgery. Methods Recent literature associated with the clinical application of 3-D printing technique in the field of medicine, especially in foot and ankle surgery was reviewed, summarized, and analyzed. Results At present, 3-D printing technique has been applied in foot and ankle fracture, segmental bone defect, orthosis, corrective surgery, reparative and reconstructive surgery which showed satisfactory effectiveness. Currently, there are no randomized controlled trials and the medium to long term follow-up is necessary. Conclusion The printing materials, time, cost, medical ethics, and multi-disciplinary team restricted the application of 3-D printing technique, but it is still a promising technique in foot and ankle surgery.
ObjectiveTo investigate the effects of three-dimensional (3D) printed Ti6Al4V-4Cu alloy on inflammation and osteogenic gene expression in mouse bone marrow mesenchymal stem cells (BMSCs) and mouse mononuclear macrophage line RAW264.7.MethodsTi6Al4V and Ti6Al4V-4Cu alloys were prepared by selective laser melting, and the extracts of the two materials were prepared according to the biological evaluation standard of medical devices. The effects of two kinds of extracts on the proliferation of mouse BMSCs and mouse RAW264.7 cells were detected by cell counting kit 8 method. After co-cultured with mouse BMSCs for 3 days, the expression of osteogenesis- related genes [collagen type Ⅰ (Col-Ⅰ), alkaline phosphatase (ALP), Runx family transcription factor 2 (Runx-2), osteoprotegerin (OPG), and osteopontin (OPN)] were detected by real-time fluorescence quantitative PCR. After co-cultured with mouse RAW264.7 cells for 1 day, the expressions of inflammation-related genes [interleukin 4 (IL-4) and nitric oxide synthase 2 (iNOS)] were detected by real-time fluorescence quantitative PCR, and the supernatants of the two groups were collected to detect the secretion of vascular endothelial growth factor a (VEGF-a) and bone morphogenetic protein 2 (BMP-2) by ELISA. The osteogenic conditioned medium were prepared with the supernatants of the two groups and co-cultured with BMSCs for 3 days. The expressions of osteogenesis-related genes (Col-Ⅰ, ALP, Runx-2, OPG, and OPN) were detected by real-time fluorescence quantitative PCR.ResultsCompared with Ti6Al4V alloy extract, Ti6Al4V-4Cu alloy extract had no obvious effect on the proliferation of BMSCs and RAW264.7 cells, but it could promote the expression of OPG mRNA in BMSCs, reduce the expression of iNOS mRNA in RAW264.7 cells, and promote the expression of IL-4 mRNA. It could also promote the secretions of VEGF-a and BMP-2 in RAW264.7 cells. Ti6Al4V-4Cu osteogenic conditioned medium could promote the expressions of Col-Ⅰ, ALP, Runx-2, OPG, and OPN mRNAs in BMSCs. The differences were all significant (P<0.05).Conclusion3D printed Ti6Al4V-4Cu alloy can promote RAW264.7 cells to secret VEGF-a and BMP-2 by releasing copper ions, thus promoting osteogenesis through bone immune regulation, which lays a theoretical foundation for the application of metal prosthesis.
ObjectiveIn this study, three-dimensional printed (3DP) titanium implants were used for skeletal reconstructions after wide excision of chest wall. 3DP titanium implants were expected to provide a valid option with perfect anatomic fitting and personalized design in chest wall reconstruction.MethodsThere were 13 patients [mean age of 46 (24-78) years with 9 males and 4 females] who underwent adequate radical wide excision for tumors and chest wall reconstruction using 3DP titanium implants. Surgical data including patient demographic characteristics, perioperative clinical data and data from 1-year follow-up were collected and analyzed.ResultsSix patients of rib tumors, six patients of sternal tumors and one patient of sternal pyogenic osteomyelitis were finally selected for the study. The chest wall defect area was 221.0±206.0 cm2. All patients were able to maintain the integrity of the chest wall after surgery, and no abnormal breathing was found, achieving personalized and anatomical repair. Thirteen patients were successfully discharged from the hospital. Two patients developed pneumonia in the perioperative period. During the follow-up period in the first year after surgery, no implant related adverse reaction was observed, including implant rupture, implant shift, rejection reaction and allergies. One patient had wound ulcer after chemotherapy. Three patients had tumor recurrence, with the recurrence rate of 25.0%. Two patients died of tumor recurrence, with a mortality rate of 16.7%.Conclusion3DP titanium implant is a safe and effective material for chest wall reconstruction.
ObjectiveTo evaluate the effectiveness of three-dimensional (3D) printing artificial vertebral body and interbody fusion Cage in anterior cervical disectomy and fusion (ACCF) combined with anterior cervical corpectomy and fusion (ACDF).MethodsThe clinical data of 29 patients with multilevel cervical spondylotic myelopathy who underwent ACCF combined with ACDF between May 2018 and December 2019 were retrospectively analyzed. Among them, 13 patients were treated with 3D printing artificial vertebral body and 3D printing Cage as 3D printing group and 16 patients with ordinary titanium mesh Cage (TMC) and Cage as TMC group. There was no significant difference in gender, age, surgical segment, Nurick grade, disease duration, and preoperative Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score, and Cobb angle of fusion segment between the two groups (P>0.05). The operation time, intraoperative blood loss, hospitalization stay, complications, and implant fusion at last follow-up were recorded and compared between the two groups; JOA score was used to evaluate neurological function before operation, immediately after operation, at 6 months after operation, and at last follow-up; VAS score was used to evaluate upper limb and neck pain. Cobb angle of fusion segment was measured and the difference between the last follow-up and the immediate after operation was calculated. The height of the anterior border (HAB) and the height of the posterior border (HPB) were measured immediately after operation, at 6 months after operation, and at last follow-up, and the subsidence of implant was calculated.ResultsThe operation time of 3D printing group was significantly less than that of TMC group (t=3.336, P=0.002); there was no significant difference in hospitalization stay and intraoperative blood loss between the two groups (P>0.05). All patients were followed up 12-19 months (mean, 16 months). There was no obvious complication in both groups. There were significant differences in JOA score, VAS score, and Cobb angle at each time point between the two groups (P<0.05). There was an interaction between time and group in the JOA score (F=3.705, P=0.025). With time, the increase in JOA score was different between the 3D printing group and the TMC group, and the increase in the 3D printing group was greater. There was no interaction between time and group in the VAS score (F=3.038, P=0.065), and there was no significant difference in the score at each time point between the two groups (F=0.173, P=0.681). The time of the Cobb angle interacted with the group (F=15.581, P=0.000). With time, the Cobb angle of the 3D printing group and the TMC group changed differently. Among them, the 3D printing group increased more and the TMC group decreased more. At last follow-up, there was no significant difference in the improvement rate of JOA score between the two groups (t=0.681, P=0.502), but the Cobb angle difference of the 3D printing group was significantly smaller than that of the TMC group (t=5.754, P=0.000). At last follow-up, the implant fusion rate of the 3D printing group and TMC group were 92.3% (12/13) and 87.5% (14/16), respectively, and the difference was not significant (P=1.000). The incidence of implant settlement in the 3D printing group and TMC group at 6 months after operation was 15.4% (2/13) and 18.8% (3/16), respectively, and at last follow-up were 30.8% (4/13) and 56.3% (9/16), respectively, the differences were not significant (P=1.000; P=0.264). The difference of HAB and the difference of HPB in the 3D printing group at 6 months after operation and last follow-up were significantly lower than those in the TMC group (P<0.05).ConclusionFor patients with multilevel cervical spondylotic myelopathy undergoing ACCF combined with ACDF, compared with TMC and Cage, 3D printing artificial vertebrae body and 3D printing Cage have the advantages of shorter operation time, better reduction of height loss of fusion vertebral body, and maintenance of cervical physiological curvature, the early effectiveness is better.
ObjectiveTo study the feasibility of preparation of the individualized femoral prosthesis through computer assisted design and electron beammelting rapid prototyping (EBM-RP) metal three-dimensional (3D) printing technology. MethodsOne adult male left femur specimen was used for scanning with 64-slice spiral CT; tomographic image data were imported into Mimics15.0 software to reconstruct femoral 3D model, then the 3D model of individualized femoral prosthesis was designed through UG8.0 software. Finally the 3D model data were imported into EBM-RP metal 3D printer to print the individualized sleeve. ResultsAccording to the 3D model of individualized prosthesis, customized sleeve was successfully prepared through the EBM-RP metal 3D printing technology, assembled with the standard handle component of SR modular femoral prosthesis to make the individualized femoral prosthesis. ConclusionCustomized femoral prosthesis accurately matching with metaphyseal cavity can be designed through the thin slice CT scanning and computer assisted design technology. Titanium alloy personalized prosthesis with complex 3D shape, pore surface, and good matching with metaphyseal cavity can be manufactured by the technology of EBM-RP metal 3D printing, and the technology has convenient, rapid, and accurate advantages.
ObjectiveTo explore a new method of treating serious tibiofibula comminuted fracture by using three-dimensional (3-D) printing personalized external fixator. MethodsIn April 2015, a male patient (aged 18 years with a height of 171 cm and a weight of 67 kg) with left tibiofibula comminuted fracture was included in the study. Computer-assisted reduction technique combined with 3-D printing was used to develop a customised personalized external fixator for fracture reduction. The effectiveness was observed. ResultsThe operation time was about 10 minutes without fluoroscopy, and successful reduction was obtained. The patient had equal limb length after operation. X-ray films showed that the posterior angulation of distal fracture was corrected 37°, and the eversion angle was corrected 4°. The tibial fractures had good paraposition or alignment, and the lower limb force line was corrected completely. No new fracture displacement occurred. The clinical healing time of fracture was 3.5 months and the bone union was achieved after 8 months. The function of affected limb recovered well after operation. ConclusionA personalized external fixator for serious tibiofibula comminuted fracture reduction made by 3-D printing technique has the merits of easy manipulation, high individuation, accurate reduction, stable fixation, and no need of fluoroscopy.