Objective To investigate the effectiveness of sacroiliac screw implantation assisted by three-dimensional (3D) printed faceted honeycomb guide plate in the treatment of posterior pelvic ring fracture. Methods The clinical data of 40 patients with posterior pelvic ring fractures treated with sacroiliac screw implantation between December 2019 and December 2022 were retrospectively analyzed. Among them, 18 cases were treated with sacroiliac screws fixation assisted by 3D printed faceted honeycomb guide plate (guide plate group), and 22 cases were treated with sacroiliac screws percutaneously fixation under fluoroscopy (conventional group). There was no significant difference in baseline data (P>0.05) such as gender, age, time from injury to operation, and Dennis classification between the two groups. The implantation time, frequency of C-arm X-ray fluoroscopy, frequency of guide pin adjustment of each sacroiliac screw, and postoperative complications and bone healing were recorded. Majeed score was used to evaluate the functional recovery at 6 months after operation, and CT was used to observe whether the screw penetrated the bone cortex. The deviation between the virtual position and the actual position of the screw tip, the sacral foramen, and the screw entry point was measured on the sagittal CT images of the guide plate group. Results The number of screws implanted in S1 and S2 vertebral bodies was 14 and 16 respectively in the guide plate group, and 17 and 18 respectively in the conventional group. The implantation time of each sacroiliac screw, the frequency of C-arm X-ray fluoroscopy, and the frequency of guide pin adjustment in S1, S2, and all vertebrae in the guide plate group were significantly less than those in the conventional group (P<0.05). Patients in both groups were followed up 8-48 months, with an average of 19.7 months. There was no incision infection, screw displacement, or internal fixation loosening in both groups. Callus growth was observed in all patients at 12 weeks after operation, and bone healing was achieved in all patients. The healing time ranged from 12 to 24 weeks, with an average of 15.7 weeks. No sacroiliac screw penetrated the bone cortex in the guide plate group; 2 patients in the conventional group had sacroiliac screws penetrating the bone cortex without damaging blood vessels or nerves. In the guide plate group, the deviation between the virtual position and the actual position of the screw tip, the sacral foramen, and the screw entry point were (2.91±1.01), (2.10±0.74), and (1.67±0.70) mm, respectively, with an average deviation of (2.19±1.22) mm. There was no significant difference in Majeed function evaluation between the two groups at 6 months after operation (P>0.05). Conclusion The application of 3D printed faceted honeycomb guide plate in sacroiliac screw implantation for posterior pelvic ring fracture can shorten the screw implantation time, reduce the frequency of fluoroscopy and guide pin adjustment, and reduce the risk of screw penetration through the bone cortex.
Three-dimensional (3D) bio-printing is a novel engineering technique by which the cells and support materials can be manufactured to a complex 3D structure. Compared with other 3D printing methods, 3D bio-printing should pay more attention to the biocompatible environment of the printing methods and the materials. Aimed at studying the feature of the 3D bio-printing, this paper mainly focuses on the current research state of 3D bio-printing, with the techniques and materials of the bio-printing especially emphasized. To introduce current printing methods, the inkjet method, extrusion method, stereolithography skill and laser-assisted technique are described. The printing precision, process, requirements and influence of all the techniques on cell status are compared. For introduction of the printing materials, the cross-link, biocompatibility and applications of common bio-printing materials are reviewed and compared. Most of the 3D bio-printing studies are being remained at the experimental stage up to now, so the review of 3D bio-printing could improve this technique for practical use, and it could also contribute to the further development of 3D bio-printing.
ObjectiveTo explore the feasibility of three-dimensional (3D) bioprinted adipose-derived stem cells (ADSCs) combined with gelatin methacryloyl (GelMA) to construct tissue engineered cartilage.MethodsAdipose tissue voluntarily donated by liposuction patients was collected to isolate and culture human ADSCs (hADSCs). The third generation cells were mixed with GelMA hydrogel and photoinitiator to make biological ink. The hADSCs-GelMA composite scaffold was prepared by 3D bioprinting technology, and it was observed in general, and observed by scanning electron microscope after cultured for 1 day and chondrogenic induction culture for 14 days. After cultured for 1, 4, and 7 days, the composite scaffolds were taken for live/dead cell staining to observe cell survival rate; and cell counting kit 8 (CCK-8) method was used to detect cell proliferation. The composite scaffold samples cultured in cartilage induction for 14 days were taken as the experimental group, and the composite scaffolds cultured in complete medium for 14 days were used as the control group. Real-time fluorescent quantitative PCR (qRT-PCR) was performed to detect cartilage formation. The relative expression levels of the mRNA of cartilage matrix gene [(aggrecan, ACAN)], chondrogenic regulatory factor (SOX9), cartilage-specific gene [collagen type Ⅱ A1 (COLⅡA1)], and cartilage hypertrophy marker gene [collagen type ⅩA1 (COLⅩA1)] were detected. The 3D bioprinted hADSCs-GelMA composite scaffold (experimental group) and the blank GelMA hydrogel scaffold without cells (control group) cultured for 14 days of chondrogenesis were implanted into the subcutaneous pockets of the back of nude mice respectively, and the materials were taken after 4 weeks, and gross observation, Safranin O staining, Alcian blue staining, and collagen type Ⅱ immunohistochemical staining were performed to observe the cartilage formation in the composite scaffold.ResultsMacroscope and scanning electron microscope observations showed that the hADSCs-GelMA composite scaffolds had a stable and regular structure. The cell viability could be maintained at 80%-90% at 1, 4, and 7 days after printing, and the differences between different time points were significant (P<0.05). The results of CCK-8 experiment showed that the cells in the scaffold showed continuous proliferation after printing. After 14 days of chondrogenic induction and culture on the composite scaffold, the expressions of ACAN, SOX9, and COLⅡA1 were significantly up-regulated (P<0.05), the expression of COLⅩA1 was significantly down-regulated (P<0.05). The scaffold was taken out at 4 weeks after implantation. The structure of the scaffold was complete and clear. Histological and immunohistochemical results showed that cartilage matrix and collagen type Ⅱ were deposited, and there was cartilage lacuna formation, which confirmed the formation of cartilage tissue.ConclusionThe 3D bioprinted hADSCs-GelMA composite scaffold has a stable 3D structure and high cell viability, and can be induced differentiation into cartilage tissue, which can be used to construct tissue engineered cartilage in vivo and in vitro.
A method of ultrasonic simulation based on the FIELD II software platform for carotid artery plaque was proposed according to the analysis for geometrical shape, tissue characteristics and acoustic properties of carotid artery plaques in clinic, and then a simulation system was developed by using the MATLAB graphical user interface (GUI). In the simulation and development, a three-dimensional geometric model of blood vessel with plaques was set up by using the metaball implicit surface technique, and a tissue model was established based on the scatterers with spatial position of gamma random distribution. Comparison of the statistical and geometrical characteristics from simulated ultrasound B-mode images with those based on clinical ones and preset values, the results fully demonstrated the effectiveness of the simulation methods and system.
Spinal fusion is a standard operation for treating moderate and severe intervertebral disc diseases. In recent years, the proportion of three-dimensional printing interbody fusion cage in spinal fusion surgery has gradually increased. In this paper, the research progress of molding technology and materials used in three-dimensional printing interbody fusion cage at present is summarized. Then, according to structure layout, three-dimensional printing interbody fusion cages are classified into five types: solid-porous-solid (SPS) type, solid-porous-frame (SPF) type, frame-porous-frame (FPF) type, whole porous cage (WPC) type and others. The optimization process of three-dimensional printing interbody fusion cage and the advantages and disadvantages of each type are analyzed and summarized in depth. The clinical application of various types of 3D printed interbody fusion cage was introduced and summarized later. Lastly, combined with the latest research progress and achievements, the future research direction of three-dimensional printing interbody fusion cage in molding technology, application materials and coating materials is prospected in order to provide some reference for scholars engaged in interbody fusion cage research and application.
Objective The combined appl ication of green fluorescent protein (GFP) and confocal laser scanning microscope three-dimensional reconstruction (CLSM-3DR) were used to monitor the construction and in vivo transplantation of tissue engineered bone (TEB), to provide for technology in selection of scaffolds and three-dimensional constructional methods. Methods After bone marrow mesenchymal stem cells (BMSCs) were isolated from a 2-year-old green goat by a combination method of density gradient centrifugation and adherent culture, and the expressions of CD29, CD60L, CD45, and CD44 in BMSCs were detected by flow cytometry. Plasmid of pLEGFP-N1 was ampl ified, digested by enzymes (Hind III, BamH I, Sal I, and Bgl II), and identified. Transfection of pLEGFP-N1 into PT67 cells was performed under the help of l iposome. Positive PT67 cells were picked out with G418, and prol iferated for harvesting virus. Based on the titre of virus, after BMSCs were infected by virus containing pLEGFP-N1, GFP positive BMSCs were collected and prol iferated for seeding cells. TEB was fabricated by GFP positive BMSCs and decalcified bone matrix (DBM) and observed by CLSM-3DR for the evaluation of the distribution and prol iferation of seeding cells. After TEB was transplanted in the defect of goat femur, CLSM was used for observing the survival and distribution of GFP positive cells in the grafts. Results The isolated cells were fibroblast-l ike morphous, with the positive expression of CD29 and CD44, and negative expression of CD60L and CD45. The digested production of pLEGFP-N1 was collected for ionophoresis, whose results showed the correct fragment length (6 900 bp). The virus of pLEGFP-N1 was harvested by transfection of pLEGFP-N1 into PT67 cells and used for further infection to obtain GFP positive BMSCs. The prol iferated GFP positive BMSCs and DBM were used for fabrication of TEB. The distribution, prol iferation, and migration of BMSCs in TEB were observed by CLSM-3DR. GFP positive cells also were observed in images of TEB graft in goat femur 28 days after transplantation. Conclusion The BMSCs labeled by GFP in three-dimensional scaffold in vivo were monitored well by CLSM-3DR. It suggests a wide use potency in monitoring of three-dimensional cultured TEB.
Objective To analyze the kinematic changes of the hip joint after total hip arthroplasty (THA) through three-dimensional gait analysis. Methods Patients with hip joint diseases admitted between October 2022 and June 2023 were selected as the subjects. The patients who met the selective criteria were finally included in the THA group. The healthy volunteers matched with the THA group in the same age were included as the control group. Baseline data including age, gender, body mass index (BMI), and laterality were compared between the two groups. The Harris hip score (HHS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were recorded preoperatively and at last follow-up in the THA group. Three-dimensional motion capture system was utilized to collect spatiotemporal parameters and kinematic data during walking, including stride length, cadence, and maximum/minimum values, range of motion (ROM) in hip joint abduction/adduction, external/internal rotation, and flexion/extension, as well as gait scores. Differences between the two groups were analyzed. Additionally, the correlation between gait scores and postoperative HHS and WOMAC scores were analyzed in the THA group. Finally, the kinematic data of each degree of freedom (DOF) were fitted into a gait diagram, and the dynamic changes of the 3-DOF of the hip joint during the gait cycle were quantitatively analyzed. ResultsThere was no significant difference in gender, age, laterality, and BMI between the two groups (n=20, P>0.05). The mean follow-up time in the THA group was 9.9 months (range, 6-12 months). The HHS and WOMAC scores at last follow-up in the THA group showed significant improvement when compared with preoperative scores (P<0.05). Gait scores were positively correlated with postoperative HHS score (r=0.585, P=0.007) and negatively correlated with WOMAC score (r=–0.619, P=0.004). There was no significant difference in stride length and cadence between the THA and control groups (P>0.05), but gait score was significantly lower in the THA group than in the control group (P<0.05). There was no significant difference in maximum and minimum values of flexion/extension, external/internal rotation, and abduction/adduction between the two groups (P>0.05); however, ROM in the THA group was significantly lower than that in the control group (P<0.05). There were significant differences between the two groups of flexion/extension in multiple phases of the gait cycle (P<0.05). ConclusionEarly post-THA hip joint kinematics exhibit relative adduction, external rotation, and flexion during the gait cycle compared to normal individuals, with incomplete recovery of kinematic parameters in three degrees of freedom. Significant differences in flexion are observed at multiple phases of the gait cycle compared to normal individuals.
ObjectiveTo review the research progress of digital occlusion setup in orthognathic surgery. Methods The literature related to digital occlusion setup in orthognathic surgery in recent years was consulted, and the imaging basis, methods, clinical applications as well as existing problems were reviewed. Results Digital occlusion setup in orthognathic surgery includes manual, semi-automatics, and fully automatic methods. The manual method mainly relies on visual cues for operation, which is difficult to ensure the best occlusion set up, though relatively flexible. The semi-automatic method utilizes the computer software for partial occlusion set up and adjustment, but the occlusion result is still largely depended by manual operation. The fully automatic method completely depends on the operation of computer software, and targeted algorithms for different occlusion reconstruction situations are needed. Conclusion The preliminary research results have confirmed the accuracy and reliability of digital occlusion setup in orthognathic surgery, but there are still some limitations. Further research is needed in terms of postoperative outcomes, doctor and patient acceptance, planning time and cost-effectiveness.
Objective To study the hook of hamate bone by anatomy and iconography methods in order to provide information for the cl inical treatment of injuries to the hook of hamate bone and the deep branch of ulnar nerve. Methods Fifty-two upper l imb specimens of adult corpses contributed voluntarily were collected, including 40 antisepticized old specimens and 12 fresh ones. The hook of hamate bone and its adjacent structure were observed. Twentyfour upper l imbs selected randomly from specimens of corpses and 24 upper l imbs from 12 healthy adults were investigated by computed tomography (CT) three-dimensional reconstruction, and then related data were measured. The measurement results of24 specimens were analyzed statistically. Results The hook of hamate bone is an important component of ulnar carpal canal and carpal canal, and the deep branch of ulnar nerve is located closely in the inner front of the hook of hamate bone. The flexor tendons of the forth and the l ittle fingers are in the innermost side, closely l ie next to the outside of the hook of hamate bone. The hamate bone located between the capitate bone and the three-cornered bone with wedge-shaped. The medial-, lateral-, and front-sides are all facies articularis. The hook of hamate bone has an approximate shape of a flat plate. The position migrated from the body of the hamate bone, the middle of the hook and the enlargement of the top of the hook were given the names of “the basis of the hook”, “the waist of the hook”, and “the coronal of the hook”, respectively. The short path of the basement are all longer than the short path of the waist. The long path of the top of the hook is the maximum length diameter of the hook of hamate bone, and is longer than the long path of the basement and the long path of the waist. The iconography shape and trait of the hook of hamate bone is similar to the anatomy result. There were no statistically significant differences (P gt; 0.05) between two methods in the seven parameters as follows: the long path of the basement of the hook, the short path of the basement of the hook, the long path of the waist of thehook, the short path of the waist of the hook, the long path of the top of the hook, the height of the hook, of hamate bone, and the distance between the top and the waist of the hook. Conclusion The hook of hamate bone can be divided into three parts: the coronal part, the waist part, and the basal part; fracture of the hamate bone can be divided into fracture of the body, fracture of the hook, and fracture of the body and the hook. Facture of the hook of hamate bone or fracture unnion can easily result in injure of the deep branch of ulnar nerve and the flexor tendons of the forth and the l ittle fingers. The measurement results of CT threedimensional reconstruction can be used as reference value directly in cl inical treatments.
Three-dimensional (3D) printing, an emerging rapid prototyping technology, has been widely used in biomedical field. 3D printing was originally used to construct the visualization models and molds in medicine. With the development of 3D printing in biomedical field, the technology was gradually applied in complex tissue regeneration and organ reconstruction. Artificial tissues and organs obtained by 3D printing are expected to be used for organ transplantation, new drug development and drug toxicity evaluation in the field of medicine and health care research. This paper describes the individualized application of 3D printing technology in liver surgery and introduces the research progress of 3D bioprinting technology in liver transplantation, drug metabolism and hepatotoxicity evaluation, and prospects its future development trend to provide a reference for further study.
