ObjectiveTo solve the fixation problem between ligament grafts and host bones in ligament reconstruction surgery by using ligament-bone composite scaffolds to repair the ligaments, to explore the fabrication method for ligament-bone composite scaffolds based on three-dimensional (3-D) printing technique, and to investigate their mechanical and biological properties in animal experiments. MethodsThe model of bone scaffolds was designed using CAD software, and the corresponding negative mould was created by boolean operation. 3-D printing techinique was employed to fabricate resin mold. Ceramic bone scaffolds were obtained by casting the ceramic slurry in the resin mould and sintering the dried ceramics-resin composites. Ligament scaffolds were obtained by weaving degummed silk fibers, and then assembled with bone scaffolds and bone anchors. The resultant ligament-bone composite scaffolds were implanted into 10 porcine left anterior cruciate ligament rupture models at the age of 4 months. Mechanical testing and histological examination were performed at 3 months postoperatively, and natural anterior cruciate ligaments of the right sides served as control. ResultsBiomechanical testing showed that the natural anterior cruciate ligament of control group can withstand maximum tensile force of (1 384±181) N and dynamic creep of (0.74±0.21) mm, while the regenerated ligament-bone scaffolds of experimental group can withstand maximum tensile force of (370±103) N and dynamic creep of (1.48±0.49) mm, showing significant differences (t=11.617,P=0.000; t=-2.991,P=0.020). In experimental group, histological examination showed that new bone formed in bone scaffolds. A hierarchical transition structure regenerated between ligament-bone scaffolds and the host bones, which was similar to the structural organizations of natural ligament-bone interface. ConclusionLigament-bone composite scaffolds based on 3-D printing technique facilitates the regeneration of biomimetic ligament-bone interface. It is expected to achieve physical fixation between ligament grafts and host bone.
ObjectiveTo evaluate the safety and application value of three-dimensional reconstruction for localization of pulmonary nodules in thoracoscopic lung wedge resection.MethodsThe clinical data of 96 patients undergoing thoracoscopic lung wedge resection in our hospital from January 2019 to August 2020 were retrospectively reviewed and analyzed, including 30 males and 66 females with an average age of 57.62±12.13 years. The patients were divided into two groups, including a three-dimensional reconstruction guided group (n=45) and a CT guided Hook-wire group (n=51). The perioperative data of the two groups were compared.ResultsAll operations were performed successfully. There was no statistically significant difference between the two groups in the failure rate of localization (4.44% vs. 5.88%, P=0.633), operation time [15 (12, 19) min vs. 15 (13, 17) min, P=0.956], blood loss [16 (10, 20) mL vs. 15 (10, 19) mL, P=0.348], chest tube placement time [2 (2, 2) d vs. 2 (2, 2) d, P=0.841], resection margin width [2 (2, 2) cm vs. 2 (2, 2) cm, P=0.272] or TNM stage (P=0.158). The complications of CT guided Hook-wire group included pneumothorax in 2 patients, hemothorax in 2 patients and dislodgement in 4 patients. There was no complication related to puncture localization in the three-dimensional reconstruction guided group.ConclusionBased on three-dimensional reconstruction, the pulmonary nodule is accurately located. The complication rate is low, and it has good clinical application value.
Reconstructing three-dimensional (3D) models from two-dimensional (2D) images is necessary for preoperative planning and the customization of joint prostheses. However, the traditional statistical modeling reconstruction shows a low accuracy due to limited 3D characteristics and information loss. In this study, we proposed a new method to reconstruct the 3D models of femoral images by combining a statistical shape model with Laplacian surface deformation, which greatly improved the accuracy of the reconstruction. In this method, a Laplace operator was introduced to represent the 3D model derived from the statistical shape model. By coordinate transformations in the Laplacian system, novel skeletal features were established and the model was accurately aligned with its 2D image. Finally, 50 femoral models were utilized to verify the effectiveness of this method. The results indicated that the precision of the method was improved by 16.8%–25.9% compared with the traditional statistical shape model reconstruction. Therefore, the method we proposed allows a more accurate 3D bone reconstruction, which facilitates the development of personalized prosthesis design, precise positioning, and quick biomechanical analysis.
Objective To develop three-dimensional (3D) porous nanofiber scaffold of PLGA-silk fibroincollagen and to investigate its cytocompatibil ity in vitro. Methods Method of electrostatic spinning was used to prepare 3D porous nanofiber scaffold of PLGA-silk fibroin-collagen (the experimental group) and 3D porous nanofiber scaffold of PLGA (the control group). The scaffold in each group was observed by scanning electron microscope (SEM). The parameters of scaffold fiber diameter, porosity, water absorption rate, and tensile strength were detected. SC harvested from the bilateral brachial plexus and sciatic nerve of 8 SD suckl ing rats of inbred strains were cultured. SC purity was detected by S-100 immunohistochemistry staining. The SCs at passage 4 (5 × 104 cells/mL) were treated with the scaffold extract of each group at a concentration of 25%, 50%, and 100%, respectively; the cells treated with DMEM served as blank control group. MTT method was used to detect absorbance (A) value 1, 3, 5, and 7 days after culture. The SC at passage 4 were seeded on the scaffold of the experimental and the control group, respectively. SEM observation was conducted 2, 4, and 6 days after co-culture, and laser scanning confocal microscope (LSCM) observation was performed 4 days after co-culture for the growth condition of SC on the scaffold. Results SEM observation: the scaffold in two groups had interconnected porous network structure; the fiber diameter in the experimental and the control group was (141 ± 9) nm and (205 ± 11) nm, respectively; the pores in the scaffold were interconnected; the porosity was 87.4% ± 1.1% and 85.3% ± 1.3%, respectively; the water absorption rate was 2 647% ± 172% and 2 593% ± 161%, respectively; the tensile strength was (0.32 ± 0.03) MPa and (0.28 ± 0.04) MPa, respectively. S-100 immunohistochemistry staining showed that the SC purity was 96.5% ± 1.3%. MTT detection: SC grew well in the different concentration groups and the control group, the absorbance (A) value increased over time, significant differences were noted among different time points in the same group (P lt; 0.05), and there was no significant difference between the different concentration groups and the blank control group at different time points (P gt; 0.05). SEM observation: in the experimental group, SC grew well on the scaffold, axon connection occurred 4 days after co-culture, the cells prol iferated massively and secreted matrix 6 days after co-culture, and the growth condition of the cells was better than the control group. The condition observed by LSCM 4 days after co-culture was the same as that of SEM. Conclusion The 3D porous nanofiber scaffoldof PLGA-silk fibroin-collagen prepared by the method of electrostatic spinning is safe, free of toxicity, and suitable for SC growth, and has good cytocompatibil ity and proper aperture and porosity. It is a potential scaffold carrier for tissue engineered nerve.
Objective To investigate the cl inical directive significance of three-dimensional reconstruction of CT in treating mandibular angle hypertrophy. Methods Between March 2009 and January 2011, 18 patients with mandibular angle hypertrophy were treated using the three-dimensional reconstruction technology of CT. All patients were female, aged20-36 years with an average of 25 years. Eighteen patients included: 14 single mandibular angle hypertrophy, 3 mandibular angle hypertrophy with masseter hypertrophy, and 1 mandibular angle hypertrophy with bilateral asymmetry; 6 cases of ptosis of mandibular angle, 9 cases of prominent mandibular angle, and 3 cases of introversive mandibular angle. According to the types of mandibular angle hypertrophy, the surgical methods could be correctly chosen. The procedure was planned and simulated; the osteotomy l ine was marked and the osteotomy was measured on the workstations of three-dimensional reconstruction. Results No fracture of mandible occurred in the operation. Facial nerve temporary attack occurred in 1 case and recovered at 3 months after operation. All patients were followed up 6-12 months (mean, 7.6 months). After 6 months of operation, the effectiveness was satisfactory in 15 cases, basically satisfactory in 2 cases, and unsatisfactory in 1 case (bilateral asymmetry). Conclusion Based on three-dimensional reconstruction technology of CT, surgical design performed on the model will promote the accuracy of operation. Basically symmetrical appearances can be achieved with satisfactory results.
ObjectiveTo investigate the effectiveness of individual percutaneous cannulated screws fixation of computer-assisted design combined with three-dimensional (3D) guide plate by comparing with cast immobilization and open internal fixation for treatment of Herbert type Ib scaphoid fracture. MethodsBetween January 2010 and June 2015, 56 patients with fresh Herbert type Ib scaphoid fracture were treated with cast immobilization in 16 cases (external fixation group), with open reduction and internal fixation in 20 cases (open reduction group), and with individual percutaneous cannulated screws fixation of computer-assisted design combined 3D guide plate in 20 cases (minimal invasion group). There was no significant difference in gender, age, injury cause, side, disease duration, and classification of fractures between groups P>0.05).The time of bone union, bone nonunion rate, return-to-work time, wrist range of motion (ROM), and Mayo function score were recorded and compared. ResultsPrimary healing of incision was obtained in open reduction group and minimally invasion group, without related complications. The cases were followed up 10-24 months (mean, 16.6 months). The time of bone union and return-to-work time of minimal invasion group were significantly shorter than those of the other 2 groups (P<0.05), and the rate of bone nonunion was significantly lower than that of the other 2 groups (P<0.05). At last follow-up, the wrist ROM of minimal invasion group[(104.40±3.46)°] was significantly larger than that of external group[(94.20±2.42)°] and open reduction group[(96.40±2.66)°] (P<0.05). According to Mayo function score, the results were excellent in 6 cases, good in 5 cases, fair in 2 cases, and poor in 3 cases in external fixation group, with an excellent and good rate of 69%; the results were excellent in 9 cases, good in 7 cases, fair in 2 cases, and poor in 2 cases in open reduction group, with an excellent and good rate of 80%; the results were excellent in 16 cases, good in 3 cases, and fair in1 case in minimal invasion group, with an excellent and good rate of 95%; there was significant difference in excellent and good rate among groups (P<0.05). ConclusionIndividual percutaneous cannulated screws fixation of computer-assisted design combined with 3D guide plate has satisfactory effectiveness in the treatment of Herbert type Ib scaphoid fractures, with the advantages of mini-invasion, high accuracy, high rate of bone union, less complication, early return-to-work time.
For the damage and loss of tissues and organs caused by urinary system diseases, the current clinical treatment methods have limitations. Tissue engineering provides a therapeutic method that can replace or regenerate damaged tissues and organs through the research of cells, biological scaffolds and biologically related molecules. As an emerging manufacturing technology, three-dimensional (3D) bioprinting technology can accurately control the biological materials carrying cells, which further promotes the development of tissue engineering. This article reviews the research progress and application of 3D bioprinting technology in tissue engineering of kidney, ureter, bladder, and urethra. Finally, the main current challenges and future prospects are discussed.
【Abstract】 Objective To determine the three-dimensional stabil ity of atlantoaxial reconstruction withanterior approach screw fixation through C2 vertebral body to C1 lateral mass and Gall ie’s technique (ASMG) for C1,2instabil ity. Methods Twenty-five human cadaveric specimens (C0-3 ) were divided randomly into 5 groups (n=5). Thethree-dimensional ranges of motion C1 relative to C2 were measured under the five different conditions：the intact state group (group A), type II odontoid fracture group (group B), posterior C1,2 transarticular screw fixation group (group C), ASM group (group D) and ASMG group (group E). The three-dimensional ranges of motions C1 relative to C2 by loading ± 1.5 Nm were measured under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation. The obtained data was statistically analyzed. Results In each group, the three-dimensional ranges of motion C1 relative to C2 under the six conditions of flexion/extension, left/right lateral bending, and left/right axial rotation were as follows: in group A (8.10 ± 1.08), (8.49 ± 0.82), (4.79 ± 0.47), (4.93 ± 0.34), (28.20 ± 0.64), (29.30 ± 0.84)°; in group B (13.60 ± 1.25), (13.80 ± 0.77), (9.64 ± 0.53), (9.23 ± 0.41), (34.90 ± 0.93), (34.90 ± 1.30)°; in group C (1.62 ± 0.10), (1.90 ± 0.34), (1.25 ± 0.13), (1.37 ± 0.28), (0.97 ± 0.14), (1.01 ± 0.17)°; in group D (2.03 ± 0.26), (2.34 ± 0.49), (1.54 ± 0.22), (1.53 ± 0.30), (0.80 ± 0.35), (0.76 ± 0.30)°; in group E (0.35 ± 0.12), (0.56 ± 0.34), (0.44 ± 0.15), (0.55 ± 0.16), (0.43 ± 0.07), (0.29 ± 0.06)°. Under the six conditions, there were generally significant differences between group A and other four groups, and between group B and groups C, D and E (P lt; 0.001), and between group E and groups C, D in flexion/ extension and left/right lateral bending (P lt; 0.05). There was no significant difference between group E and groups C, D in left/right axial rotation (P gt; 0.05). Conclusion In vivo biomechanical studies show that ASMG operation has unique superiority in the reconstruction of the atlantoaxial stabil ity, especially in controll ing stabil ity of flexion/extension and left/right lateral bending, and thus it ensures successful fusion of the implanted bone. It is arel iable surgical choice for the treatment of the obsolete instabil ity or dislocation of C1, 2 joint.
ObjectiveTo summarize the research progress of several three-dimensional (3-D) printing scaffold materials in bone tissue engineering. MethodThe recent domestic and international articles about 3-D printing scaffold materials were reviewed and summarized. ResultsCompared with conventional manufacturing methods, 3-D printing has distinctive advantages, such as enhancing the controllability of the structure and increasing the productivity. In addition to the traditional metal and ceramic scaffolds, 3-D printing scaffolds carrying seeding cells and tissue factors as well as scaffolds filling particular drugs for special need have been paid more and more attention. ConclusionsThe development of 3-D printing porous scaffolds have revealed new perspectives in bone repairing. But it is still at the initial stage, more basic and clinical researches are still needed.
Objective To investigate the methods of establishing 3-dimensional skull model using electron beam CT(EBCT) data rapid prototyping technique, andto discuss its application in repairing crainomaxillofacial trauma. Methods The data were obtained by EBCTcontinuous volumetric scanning with 1.0 mm slice at thickness. The data were transferred to workstation for 3-dimensional surface reconstruction by computeraided design software and the images were saved as STL file. The data can be usedto control a laser rapid-prototyping device(AFS-320QZ) to construct geometricmodel. The material for the model construction is a kind of laser-sensitive resinpower, which will become a mass when scanned by laser beam .The design and simulation of operation can be done on the model. The image data were transferred to the device slice by slice. Thus a geometric model is constructed according to the image data by repeating this process. Preoperative analysis, surgery simulation and implant of bone defect could be done on this computer-aided manufacture d3D model. One case of craniomaxillofacial bone defect resulting from trauma wasreconstructed with this method. The EBCT scanning showed that the defect area was 4 cm×6 cm. The nose was flat and deviated to left. Results The -3dimensional -skull was reconstructed with EBCT data and rapid prototyping technique. The model can display the structure of 3-dimenstional anatomyand their relationship.The prefabricated implant by 3-dimensional model was well-matched with defect .The deformities of flat and deviated nose were corrected. The clinical result wassatisfactory after a follow-up of 17 months. Conclusion The 3-dimensional model of skull can replicate the prototype of disease and play an important role in the diagnosis and simulation of operation for repairing craniomaxillofacial trauma.