With the development of three-dimensional (3D) printing technology, more and more researches have focused on its application in the region of intervertebral fusion materials; the prospects are worth looking forward to. This article reviews the researches about 3D printing technology in spinal implants, and summarizes the materials and printing technology applied in the field of spinal interbody fusion, and the shortcomings in the current research and application. With the rapid development of 3D printing technology and new materials, more and more 3D printing spinal interbodies will be developed and used clinically.
Objective To manufacture a poly (lactic-co-glycolic acid) (PLGA) scaffold by low temperature deposition three-dimensional (3D) printing technology, prepare a PLGA/decellularized articular cartilage extracellular matrix (DACECM) cartilage tissue engineered scaffold by combining DACECM, and further investigate its physicochemical properties. Methods PLGA scaffolds were prepared by low temperature deposition 3D printing technology, and DACECM suspensions was prepared by modified physical and chemical decellularization methods. DACECM oriented scaffolds were prepared by using freeze-drying and physicochemical cross-linking techniques. PLGA/DACECM oriented scaffolds were prepared by combining DACECM slurry with PLGA scaffolds. The macroscopic and microscopic structures of the three kinds of scaffolds were observed by general observation and scanning electron microscope. The chemical composition of DACECM oriented scaffold was analyzed by histological and immunohistochemical stainings. The compression modulus of the three kinds of scaffolds were measured by biomechanical test. Three kinds of scaffolds were embedded subcutaneously in Sprague Dawley rats, and HE staining was used to observe immune response. The chondrocytes of New Zealand white rabbits were isolated and cultured, and the three kinds of cell-scaffold complexes were prepared. The growth adhesion of the cells on the scaffolds was observed by scanning electron microscope. Three kinds of scaffold extracts were cultured with L-929 cells, the cells were cultured in DMEM culture medium as control group, and cell counting kit 8 (CCK-8) was used to detect cell proliferation. Results General observation and scanning electron microscope showed that the PLGA scaffold had a smooth surface and large pores; the surface of the DACECM oriented scaffold was rough, which was a 3D structure with loose pores and interconnected; and the PLGA/DACECM oriented scaffold had a rough surface, and the large hole and the small hole were connected to each other to construct a vertical 3D structure. Histological and immunohistochemical qualitative analysis demonstrated that DACECM was completely decellularized, retaining the glycosaminoglycans and collagen typeⅡ. Biomechanical examination showed that the compression modulus of DACECM oriented scaffold was significantly lower than those of the other two scaffolds (P<0.05). There was no significant difference between PLGA scaffold and PLGA/DACECM oriented scaffold (P>0.05). Subcutaneously embedded HE staining of the three scaffolds showed that the immunological rejections of DACECM and PLGA/DACECM oriented scaffolds were significantly weaker than that of the PLGA scaffold. Scanning electron microscope observation of the cell-scaffold complex showed that chondrocytes did not obviously adhere to PLGA scaffold, and a large number of chondrocytes adhered and grew on PLGA/DACECM oriented scaffold and DACECM oriented scaffold. CCK-8 assay showed that with the extension of culture time, the number of cells cultured in the three kinds of scaffold extracts and the control group increased. There was no significant difference in the absorbance (A) value between the groups at each time point (P>0.05). Conclusion The PLGA/DACECM oriented scaffolds have no cytotoxicity, have excellent physicochemical properties, and may become a promising scaffold material of tissue engineered cartilage.
Mitral valve disease is the most common cardiac valve disease. The main treatment of mitral valve disease is surgery or interventional therapy. However, as the anatomy of mitral valve is complicated, the operation is particularly difficult. As a result, it requires sophisticated experiences for surgeons. Three-dimensional (3D) printing technology can transform two-dimensional medical images into 3D solid models. So it can provide clear spatial anatomical information and offer safe and personalized treatment for the patients by simulating surgery process. This article reviews the applications of 3D printing technology in the treatment of mitral valve disease.
ObjectiveTo investigate the short-term effectiveness of three-dimensional (3D) printing personalized prosthesis in the treatment of giant cell tumor of bone around knee joint.MethodsA clinical data of 9 patients with giant cell tumor of bone around knee joints and met the inclusive criteria between May 2014 and August 2017 was retrospectively analysed. There were 4 males and 5 females, with an average age of 35.8 years (range, 24-50 years). The lesion located at the distal femur in 4 cases and at the proximal tibia in 5 cases. The disease duration was 5-25 months (mean, 12.9 months). According to Campanacci grading, there were 2 patients of grade Ⅰ and 7 of grade Ⅱ. The 3D printing personalized prosthesis was designed based on the CT scanning and 3D reconstruction prepared before operation. All patients were treated with the tumor resection and 3D printing personalized prosthesis reconstruction. The radiological examination was taken to observe the tumor recurrence and the Musculoskeletal Tumor Society 1993 (MSTS93) score was used to evaluate the knee function.ResultsAll operations were successful and all incisions healed by first intention without early complications. All patients were followed up 24-40 months (mean, 31.2 months). At last follow-up, no complication such as pain, pathological fracture, prosthesis loosening, or tumor recurrence occurred. The MSTS93 score was 20-29 (mean, 24.7). The knee function was rated as excellent in 6 cases and good in 3 cases, with the excellent and good rate of 100%. ConclusionFor giant cell tumor of bone around knee joint, 3D printing personalized prosthesis has the advantages of bio-fusion with host bone, mechanical stability, good joint function, and ideal short-term effectiveness. But the middle- and long-term effectiveness still need to be further observed.
ObjectiveTo evaluate the clinical value of three-dimensional (3D) printing model in accurate and minimally invasive treatment of double outlet right ventricle (DORV).MethodsFrom August 2018 to August 2019, 35 patients (22 males and 13 females) with DORV aged from 5 months to 17 years were included in the study. Their mean weight was 21.35±8.48 kg. Ten patients who received operations guided by 3D printing model were allocated to a 3D printing model group, and the other 25 patients who received operations without guidance by 3D printing model were allocated to a non-3D printing model group. Preoperative transthoracic echocardiography and CT angiography were performed to observe the location and diameter of ventricular septal defect (VSD), and to confirm the relationship between VSD and double arteries.ResultsThe McGoon index of patients in the 3D printing model group was 1.91±0.70. There was no statistical difference in the size of VSD (13.20±4.57 mm vs. 13.40±5.04 mm, t=−0.612, P=0.555), diameter of the ascending aorta (17.10±2.92 mm vs. 16.90±3.51 mm, t=0.514, P=0.619) or diameter of pulmonary trunk (12.50±5.23 mm vs. 12.90±4.63 mm, t=−1.246, P=0.244) between CT and 3D printing model measurements. The Pearson correlation coefficients were 0.982, 0.943 and 0.975, respectively. The operation time, endotracheal intubation time, ICU stay time and hospital stay time in the 3D printing model group were all shorter than those in the non-3D printing model group (P<0.05).ConclusionThe relationship between VSD and aorta and pulmonary artery can be observed from a 3D perspective by 3D printing technology, which can guide the preoperative surgical plans, assist physicians to make reasonable and effective decisions, shorten intraoperative exploration time and operation time, and decrease the surgery-related risks.
ObjectiveTo explore the effectiveness and advantage of three-dimensional (3D) printed navigation templates assisted Ludloff osteotomy in treatment of moderate and severe hallux valgus.MethodsBetween April 2013 and February 2015, 28 patients (28 feet) with moderate and severe hallux valgus who underwent Ludloff osteotomy were randomly divided into 2 groups (n=14). In group A, the patients were treated with Ludloff osteotomy assissted with a 3D printed navigation template. In group B, the patients were treated with traditional Ludloff osteotomy. There was no significant difference in gender, age, affected side, and clinical classification between 2 groups (P>0.05). The operation time and intraoperative blood loss were recorded. The ankle function of the foot at preoperation, immediate after operation, and last follow-up were assessed by the American Orthopedic Foot and Ankle Society (AOFAS) score. Besides, the X-ray film were taken to assess the hallux valgus angle (HVA), intermetatarsal angle (IMA), and the first metatarsal length shortening.ResultsAll patients were followed up 18-40 months (mean, 26.4 months). The operation time and intraoperative blood loss in group A were significantly less than those in group B (P<0.05). The HVA, IMA, and AOFAS scores in groups A and B at immediate after operaton and last follow-up were sinificantly improved when compared with preoperative values (P<0.05); but no significant difference was found between at immediate after operation and at last follow-up (P>0.05). No significant difference was found in HVA and IMA between group A and group B at difference time points (P>0.05). There were significant differences in AOFAS score and the first metatarsal length shortening at immediate after operation and at last follow-up between 2 groups (P<0.05). Except 1 case of metastatic metatarsalgia in group B, there was no other operative complications in both groups.Conclusion3D printed navigation template assisted Ludloff osteotomy can provide accurate preoperative planning and intraoperative osteotomy. It is an ideal method for moderate and severe hallux valgus.
Objective To explore the application of individualized transiliac crest nail-grafting guide plate prepared by computer-aided design and three-dimensional (3D) printing technology in deep pelvic external fixator implantation. Methods Five patients with pelvic fractures were collected between May 2017 and February 2018. There were 4 females and 1 male with an average age of 52 years (range, 29-68 years). Pelvic fractures were classified as type B in 3 cases and type C in 2 cases by Tile classification. The interval between injury and operation was 6-14 days (mean, 9 days). The preoperative CT images of pelvic fractures were collected. The data was reconstructed by 3D imaging reconstruction workstation. An individualized transiliac crest nail-grafting guide plate was designed on the virtual 3D model. The individualized transiliac crest nail-grafting guide plate and the solid pelvic model were produced with the 3D printing technology. The individualized transiliac crest nail-grafting guide plate was used for intraoperative deep pin position on iliac crest after the preoperative simulation. The follow-up CT scans were used to determine the differences in distance from anterior superior iliac spine, convergence angle, and caudal angle between the preoperative plan and postoperative measurement. Results During the operation, the individualized transiliac crest nail-grafting guide plate was used to guide the placement of 20 pins. X-ray film and CT examination showed that all pins were well positioned. The average depth of pins was 83.16 mm (range, 70.13-100.53 mm). Fitted 3D reconstruction images showed that the entry point and orientation of the pins were all consistent with preoperative schemes. Compared with the planned nail path, there was no significant difference in the distance from anterior superior iliac spine, convergence angle, and caudal angle in the actual nail path (P>0.05). No loosening and rupture of pin, no damage of blood vessels and nerve, and shallow or deep infection occurred during 3 months follow-up, and the incisions healed by first intention. All patients were satisfied with the treatment process. The ranges of motion of hip and knee were normal, and the visual analogue scale (VAS) score was 0-3 (mean, 0.5). Conclusion The individualized transiliac crest nail-grafting guide plate technique is the improvement of traditional technique. It can increase accuracy and effective depth of pin position, enable patients to obtain pelvic mechanical stability quickly after operation, and reduce the risk of complications related to nail path.
The esophageal disease is a major clinical disease. The esophageal stent has extensive clinical applications in the treatment of esophageal diseases. However, the clinical application of esophageal stent is limited, because there are lots of complications after implantation of esophageal stent. Biodegradable esophageal stent has two advantages: biodegradability and good histocompatibility. It is expected to solve a variety of complications of esophageal stent and provide a new choice for the treatment of esophageal diseases. Standardized esophageal stents are not fully applicable to all patients. The application of 3D printing technology in the manufacture of biodegradable esophageal stent can realize the individualized treatment of esophageal stent. And meanwhile, the 3D printing technology can reduce the manufacturing cost of the stent. This review aimed to summarize and discuss the application of esophageal stent, the current research status and prospect of biodegradable esophageal stent and the prospect of 3D printing technology in degradable esophageal stent, hoping to provide evidence and perspectives for the research of biodegradable esophageal stent.
ObjectiveTo explore the feasibility of lumbar puncture models based on 3D printing technology for training junior orthopaedic surgeons to find the optimal pedicle screw insertion points.MethodsMimics software was used to design 3D models of lumbar spine with the optimal channels and alternative channels. Then, the printed lumbar spine models, plasticine, and cloth were used to build lumbar puncture models. From January 2018 to June 2019, 43 orthopedic trainees performed simulated operations to search for the insertion points of pedicle screws base on the models. The operations were performed once a day for 10 consecutive days, and the differences in operation scores and operation durations of the trainees among the 10 days were compared.ResultsAll the trainees completed the surgical training operations successfully, and there were significant differences in the operation scores (13.05±2.45, 14.02±3.96, 17.58±3.46, 21.02±2.04, 23.40±4.08, 25.14±3.72, 27.26±6.09, 33.37±4.23, 35.00±4.15, 38.49±1.70; F=340.604, P<0.001) and operation durations [(22.51±4.28), (19.93±4.28), (18.05±2.89), (17.05±1.76), (16.98±1.97), (15.47±1.74), (13.51±1.42), (12.60±2.17), (12.44±1.71), (11.91±1.87) minutes; F=102.359, P<0.001] among the 10 days.ConclusionThe 3D models of lumbar puncture are feasible and repeatable, which can contribute to surgical training.
ObjectiveTo explore the effectiveness and advantage of three-dimensional (3D) printing technology in treatment of internal or external ankle distal avulsed fracture.MethodsBetween January 2015 and January 2017, 20 patients with distal avulsed fracture of internal or external ankle were treated with the 3D guidance of shape-blocking steel plate fixation (group A), and 18 patients were treated with traditional plaster external fixation (group B). There was no significant difference in gender, age, injury cause, disease duration, fracture side, and fracture type between 2 groups (P>0.05). Recording the fracture healing rate, fracture healing time, the time of starting to ankle functional exercise, residual ankle pain, and evaluating ankle function recovery of both groups by the American Orthopaedic Foot and Ankle Society (AOFAS) score.ResultsAll patients were followed up 8-24 months, with an average of 15.5 months. In group A: all incisions healed by first intention, the time of starting to ankle functional exercise was (14±3) days, fracture healing rate was 100%, and the fracture healing time was (10.15±2.00) weeks. At 6 months, the AOFAS score was 90.35±4.65. Among them, 13 patients were excellent and 7 patients were good. All patients had no post-operative incision infection, residual ankle pain, or dysfunction during the follow-up. In group B: the time of starting to ankle functional exercise was (40±10) days, the fracture healing rate was 94.44%, and the fracture healing time was (13.83±7.49) weeks. At 6 months, the AOFAS score was 79.28±34.28. Among them, 15 patients were good, 2 patients were medium, and 1 patient was poor. During the follow-up, 3 patients (16.67%) had pain of ankle joint with different degrees. There were significant differences in the postoperative fracture healing rate, fracture healing time, the time of starting to ankle functional exercise, and postoperative AOFAS score between 2 groups (P<0.05).ConclusionApplication of 3D printing technology in treatment of internal or external ankle distal avulsed fracture is simple, safe, reliable, and effective. In particular, it is an ideal treatment for avulsed fracture.