Bone organoid construction: challenges and countermeasures / 中华创伤杂志

Bone organoids are cellular structures cultured in vitro that can mimic the structure and function of real bone tissues. Currently, significant progress has been made in the researches of bone organoids, cartilage organoids, bone callus organoids, etc. These organoids can be constructed using combinations of stem cells or specific cell types and are characterized with the potential and function of osteogenesis. Despite the immense potential applications of bone organoids, their construction still faces several challenges. For instance, there are ongoing controversies regarding the types, sources, identification, and isolation methods of skeletal stem cells. Additionally, further research is needed to select and optimize extracellular matrices suitable for bone organoid construction. Vascularization of bone organoids is a crucial factor limiting their size. Meanwhile, breakthroughs in artificial intelligence technology offer new thoughts for the construction of bone organoids. Hurdles in fundamental researches and practical needs such as bone defect repair create new opportunities for the study of bone organoids. For this purpose, the authors systematically elucidated the current researches and challenges in the construction of bone organoids and discussed countermeasures to address these challenges, aiming to provide reference for researches and translational applications of bone organoids.

Construction of double-layer bone-on-a-chip containing bone matrix / 中华创伤杂志

Objective:To construct a double-layer bone-on-a-chip containing bone matrix, with which the process of osteoblast and osteoclast differentiation in vitro is stimulated, aiming to provide a new platform for the development of osteoporosis medications. Methods:Software WorkSoild was used to design the double-layer and double-channel bone-on-a-chip and the template was fabricated by photolithography. With polydimethylsiloxane (PDMS) as the raw material, the main body of the chip was prepared by mold fabrication. The inlets and outlets of the four channels of the culture room were separated with bovine cortex bones and sealed with liquid storage columns. In the chip verification experiment, chips were divided into osteogenic and osteoclastic induction groups and osteogenic and osteoclastic control groups. In the osteogenic and osteoclastic induction groups, precursor cells of mouse embryonic osteoblast, MC3T3-E1 and mouse macrophage RAW264.7 were inoculated on the chip separately. Osteogenic induction lasted 14 days and osteoclastic induction 7 days. MC3T3-E1 cells and RAW264.7 cells were not induced in the osteogenic and osteoclastic control groups. The following indicators were observed: (1) Appearance and sealing performance of the chip: After the chip was prepared, photos were taken to observe its appearance and sealing tests were conducted to observe its sealing performance. (2) Biocompatibility: At 3 days after MC3T3-E1 cells were inoculated onto the chip and cultured and at 1, 3 and 5 days after RAW264.7 cells were inoculated onto the chip and cultured, the cell survival was observed with calcein acetoxymethyl ester/propidium iodide (AM/PI) staining and Cell Counting Kit 8 (CCK-8). (3) Osteogenic differentiation: Alkaline phosphatase (ALP) staining and alizarin red staining were performed on the cells in the osteogenic induction group to observe the osteogenic induction. RNA was collected from the osteogenic induction group and the osteogenic control group, the expression of osteoblast marker Runt-related transcription factor 2 (RUNX2), osteocalcin (OCN) and type I collagen (COL1A1) was detected by real-time florescent quantitative PCR (qPCR), and the differentiation degree and osteogenic ability of osteoblasts were observed. (4) Osteoclast differentiation: tartrate-resistant acid phosphatase (TRAP) staining was performed on cells in the osteoclastic induction group to observe osteoclast differentiation. RNA was extracted from the osteoclastic induction group and the osteoclastic control group for qPCR of osteoclast differentiation-related genes, and the expression levels of the osteoclast marker gene TRAP, cathepsin K (CTSK) and dendritic cell specific transmembrane protein (DC-STAMP) were detected.Results:The double-layer bone-on-a-chip containing bone matrix was 3 cm×3 cm in size and transparent as a whole. The structure of the system on the chip system was compact and had no seepage. It was shown by calcein AM/PI staining that at 3 days after MC3T3-E1 cells and RAW264.7 cells were cultured, very few red fluorescent dead cells were found. CCK-8 test showed that within 5 days after being cultured, the cell viability was all above 90%, indicating that the biocompatibility of the chip was good and the cells could survive and proliferate normally. The results of ALP and alizarin red staining showed that MC3T3-E1 cells successfully differentiated into osteoblasts and produced calcified nodules in the osteogenic induction group at 14 days after the induction. The qPCR results showed that the relative expression level of RUNX2 in MC3T3-E1 cells in the osteogenic induction group was 4.98±0.74, which was significantly higher than that of the control group (0.99±0.03) ( P<0.01). The relative expression level of OCN in MC3T3-E1 cells was 7.98±0.76, which was significantly higher than that of the control group (1.00±0.06) ( P<0.01). The relative expression level of COL1A1 in MC3T3-E1 cells was 7.07±0.56, which was significantly higher than that of the control group (0.97±0.03) ( P<0.01). The TRAP staining results showed that the RAW264.7 cells in the osteoclastic induction group differentiated to giant multinucleated osteoclasts, and TRAP protein was expressed in large quantity in the osteoclasts. The results of qPCR showed that the relative expression level of TRAP in RAW264.7 cells in the osteoclastic induction group was 3.35±0.37, which was significantly higher than that of the control group (1.01±0.06) ( P<0.01). The relative expression level of CTSK in RAW264.7 cells was 3.46±0.79, which was significantly higher than that of the control group (1.01±0.05) ( P<0.01). The relative expression level of DC-STAMP in RAW264.7 cells was 1.92±0.12, which was significantly higher than that of the control group (0.98±0.08) ( P<0.01). Conclusions:The double-layer bone-on-a-chip containing bone matrix is compact in structure, can be cultured in vitro for a long time, has good biocompatibility and can be used for inducing osteogenic and osteoclast differentiation. Therefore, it is expected to provide a new research platform for exploring the mechanism of osteoporosis and medication screening.

Repair of skin defect with 3D-bioprinted organoid artificial skin derived from adult stem cells in mice / 中华创伤杂志

Objective:To construct 3D-bioprinted organoid artificial skin derived from adult stem cells and investigate their effects on repair of skin defect in mice.Methods:The cell suspension mixture was prepared with human skin keratinocytes, fibroblasts and vascular endothelial cells with a ratio of 2∶1∶1 and cultured in ultra-low attachment plates, and morphological changes of cell spheres were observed with an inverted phase contrast microscope. After 7 days of culture, cell spheres were collected and immunofluorescence staining was performed to characterize the expression and structural distribution of the epidermis, dermis and blood vessels. The artificial skin composed of skin organoids were printed through 3D printing and morphology of printed artificial skin and dressing was observed. Ten immunodeficient balb/c female mice were divided into hydrogel group and organoid group, with 5 mice in each group with the method of random number table. The full-thickness skin defect model with a diameter of 1 cm was established in all mice, and the wound was covered with the hydrogel dressings in hydrogel group and with 3D-printed skin organoids of the same size in organoid group. Wound healing and healing rate of the two groups were observed at 0, 4, 8, 12 and 16 days after modeling. At 16 days after modeling, HE staining was performed on wound skin samples to observe the epidermal keratosis and dermal epidermal junction of the wound surface and Masson staining to observe the density of collagen fibers and dermal fiber thickness of the wound surface.Results:(1) The cell suspension mixture of keratinocytes, fibroblasts and vascular endothelial cells could self-aggregate into cell spheres in the ultra-low attachment plates, and it was observed with the inverted phase contrast microscope that the volume of cell spheres gradually increased with the extension of culture time. (2) Immunofluorescence staining of the cell spheres showed that epidermal markers such as keratin (K)1, K10, and K14 were expressed in the outer layer of the cell spheres, and dermal markers such as vimentin (VIM) and vascular markers CD31 were expressed in the core, which indicated the epidermis was located in the outer layer of the sphere, and the dermis and blood vessels were located in the core of the sphere, with the same structural characteristics of the skin organoids. (3) The 3D-printed organoid artificial skin and hydrogel dressing were round and transparent, with a diameter of 10 mm and a thickness of 1 mm. (4) As shown in the general observation of the wound surface, the wound area of both groups decreased with the extension of treatment time. The wound of the organoid group healed faster, which showed obvious epithelization at 4 days after modeling and basic wound healing at 16 days after modeling. At 0 day after modeling, there was no obvious difference in the appearance of wound surface between the two groups. At 4 and 8 days after modeling, the wound healing rates were (31.7±1.0)% and (52.4±5.4)% in the organoid group, and (24.3±6.8)% and (45.4±7.0)% in the hydrogel group ( P>0.05). At 12 and 16 days after modeling, the wound healing rates were (78.6±8.0)% and (91.1±5.6)% in the organoid group, and were (58.5±5.4)% and (71.9±7.8)% in the hydrogel group ( P<0.01). (5) HE staining showed that in the organoid group epidermal keratinization was found better, with the epidermis being more intact and well attached to the dermis. Epidermal keratinization was not complete in hydrogel group and the epidermis and dermis were obviously separated. Masson staining showed the formation of collagen fiber structures in the wound surface of both groups, which were blue and reticular. The collagen fiber structure was more compact and the dermal fiber thickness was smaller in the organoid group, while the collagen fiber structure was loose and the dermal fiber thickness was greater in the hydrogel group. Conclusions:Adult stem cells of skin can successfully form skin organoids in 3D culture conditions and organoid artificial skin can be constructed with 3D bioprinting technology. Compared with hydrogel dressing, 3D-bioprinted organoid artificial skin can significantly improve the healing rate in mice, with better epidermal keratinization and closer attachment of the epidermis to the dermis. Moreover, the collagen fiber structure of the wound is more compact, with smaller dermal fiber in thickness.

Construction strategies of skin organoids: a review / 中华创伤杂志

Large skin defect caused by severe trauma is a common clinical problem with high incidence, great harm, difficult treatment and poor prognosis, which not only seriously affects the quality of patients′ life, but also threatens their lives. Large skin defects are difficult to heal by themselves and the main treatment is skin transplantation. However, the source of the autologous flap is limited and may cause secondary damage to patients. The artificial skin has poor mechanical integrity that cannot be integrated, causing formation of scars, and also has the risk of immune rejection. Skin organoid technology can extremely simulate the human skin tissue and its functions. Thus, it can overcome the shortcomings of the current skin wound treatment to a certain extent and provide a new treatment for the patients with large skin defects. At present, the construction methods of skin organoids are relatively mature, but each method has its advantages and disadvantages, and the best method has not been determined yet. Moreover, the structure and function of skin organoids are relatively simple, so there is still a relatively big gap between skin organoids and real human skin. Hence, the authors reviewed the research progress in skin organoid construction strategies from organoids′ skin organoid technology, and construction methods of skin organoids, hoping to provide a reference for the construction of skin organoids with more complex structures and functions in the future.

Construction of microfluidic organ-on-a-chip and its application in simulating subchondral bone remodeling / 中华创伤杂志

Objective:To construct a microfluidic organ-on-a-chip and evaluate its capability in simulating subchondral bone remodeling during the progression of osteoarthritis.Methods:The chip′s main body was designed based on the microfluidic technology and cell co-culture technique. MC3T3-E1 cells were cultured adherently within the cell seeding micro-chamber, with the culture medium perfused at a flow rate of 0.5 ml/min at the bottom of the micro-chamber. Evaluation metrics were as follows: (1) Assessment of the microfluidic organ-on-a-chip: The growth culture medium was perfused and simulation experiments were conducted to test the concentration differences and equilibrium times of the fluid inside and at the bottom of the cell seeding micro-chamber at various time points; live-dead staining was performed to observe the biocompatibility of cells cultured continuously for 3 days and 7 days at a set flow rate, which was divided into 3-day and 7-day groups. (2) Osteogenic potential of the microfluidic organ-on-a-chip: The osteogenic induction medium was perfused, and ALP staining and PCR were performed to compare the number of the black alkaline phosphatase (ALP)-positive cells and the expression levels of osteogenesis-related marker genes including osteoblast-specific transcription factor 2 (RUNX2), type I collagen (COL1A1), bone morphogenetic protein-2 (BMP-2), and osteocalcin (OCN) under static, 3-day and 7-day perfusion conditions, which was divided into static non-induced, static-induced and perfusion-induced groups. (3) Characterization of morphology and size, and biocompatibility of extracellular vesicles (EVs) of three osteoblast subtypes: Three different subtypes of osteoblasts were obtained [endothelial-type osteoblasts (EnOB)-EVs, stromal-type osteoblasts (StOB)-EVs and mineralizing-type osteoblasts (MinOB)-EVs]. Their morphology and size were obtained through transmission electron microscopy and particle size analysis. Growth medium containing EVs of three different cell subtypes was perfused, and cell proliferation/apoptosis assay was performed to compare the biocompatibility of the addition of different EVs concentrations (1, 1.25, 2.5, and 5 μg/ml) for 24 hours, which was categorized into the EnOB-EVs group, StOB-EVs group and MinOB-EVs group. (4) Osteogenic effect of EVs from three subtypes of osteoblasts: Osteogenic induction media containing EVs from three different osteoblast subtypes were perfused for 3 days, and ALP staining and PCR were performed to compare the number of black ALP-positive cells and the expression levels of osteogenesis-related marker genes including RUNX2, COL1A1, BMP-2, and OCN, which was divided into non-EVs group, EnOB-EVs group, StOB-EVs group and MinOB-EVs group.Results:(1) Evaluation of the microfluidic organ-on-a-chip: Simulation results showed that the concentration in the top layer of the upper chamber reached more than 95% of that in the lower chamber and that the concentration in the bottom layer was about 96.5% of that in the lower chamber after 12 hours of continuous perfusion, reaching an equilibrium state of the concentration difference between the upper and lower chambers. The results of live-dead staining showed that the chip was biocompatible at a flow rate of 0.5 ml/min, and the cell survival rate at 3 and 7 days of perfusion was (99.48±0.12)% and (97.07±1.05)% ( P<0.01). (2) ALP staining results showed that at 3 days, the perfusion-induced group showed the highest number of black ALP-positive cells, followed by the static-induced group, and the least in the static non-induced group. At 7 days, the static-induced group had the highest number of black ALP-positive cells, followed by the perfusion-induced group, and the least in the static non-induced group. PCR results indicated that at 3 days, the expression levels of RUNX2, COL1A1, BMP-2, and OCN were 1.00±0.03, 1.00±0.12, 1.00±0.01, and 1.00±0.02 respectively in the static non-induced group; 1.80±0.04, 4.05±0.37, 9.80±1.94, and 4.38±0.89 respectively in the static-induced group, and 2.45±0.23, 5.48±0.42, 91.50±4.56, and 10.82±4.96 respectively in the perfusion-induced group ( P<0.01). At 7 days, the expression levels of RUNX2 was 1.00±0.01 in the static non-induced group, 1.46±0.46 in the static-induced group, and 1.11±0.08 in the perfusion-induced group ( P>0.05); the expression levels of COL1A1, BMP-2, and OCN were 1.00±0.03, 1.00±0.13, and 1.00±0.09 respectively in the static non-induced group, 9.38±0.25, 14.27±4.35, and 84.01±4.02 respectviely in the static-induced group, and 2.39±0.08, 133.64±8.87, and 86.64±8.36 respectively in the perfusion-induced group ( P<0.01). When comparing the static non-induced, static-induced, and perfusion-induced groups at both 3 and 7 days, the perfusion-induced group demonstrated the strongest osteogenic capability. (3) Characterization of morphology and size and biocompatibility of EVs from three osteoblast subtypes: Under the transmission electron microscope, EVs from EnOB-EVs, StOB-EVs, and MinOB-EVs all exhibited a typical saucer-shaped morphology. The particle sizes of EnOB-EVs, StOB-EVs, and MinOB-EVs were (91.3±14.7)nm, (106.0±16.0)nm, and (68.1±10.7)nm, respectively. Cell proliferation/apoptosis assay results indicated that the optimal administration concentration of EnOB-EVs, StOB-EVs, and MinOB-EVs was all 1.25 μg/mL. (4) Validation of osteogenic effect of the microfluidic organ-on-a-chip on three types of EVs: ALP staining results showed that the non-EVs group had the fewest black ALP-positive cells, followed by the EnOB-EVs group, then the StOB-EVs group, and the MinOB-EVs group had the most. PCR results showed that the expression levels of RUNX2, COL1A1, BMP-2, and OCN were 1.00±0.01, 1.00±0.03, 1.00±0.02, and 1.00±0.02 respectively in the non-EVs group, 1.95±0.11, 6.78±2.04, 7.99±0.57, and 6.93±3.83 repectively in the EnOB-EVs group, 0.79±0.12, 5.68±1.53, 12.59±3.15, and 25.59±0.95 respectively in the StOB-EVs group, and 0.68±0.10, 4.36±0.69, 18.75±3.21, and 34.74±3.98 repectively in the MinOB-EVs group ( P<0.01). Compared with the non-EVs group, EnOB-EVs group, StOB-EVs group, and MinOB-EVs group, the MinOB-EVs group showed the most significant osteogenic effect. Conclusions:The microfluidic organ-on-a-chip constructed using microfluidic technology and cell co-culture techniques is capable of maintaining the normal growth of MC3T3-E1 cells, enhancing their proliferation and osteogenic induction differentiation. EVs released by osteoblasts at different stages possess osteogenic effects and can accelerate the bone sclerosis in the remodeling of subchondral bone during the progression of osteoarthritis.

Expert consensus on the diagnosis and treatment of osteoporotic proximal humeral fracture with integrated traditional Chinese and Western medicine (version 2024) / 中华创伤杂志

Osteoporotic proximal humeral fracture (OPHF) is one of the common osteoporotic fractures in the aged, with an incidence only lower than vertebral compression fracture, hip fracture, and distal radius fracture. OPHF, secondary to osteoporosis and characterized by poor bone quality, comminuted fracture pattern, slow healing, and severely impaired shoulder joint function, poses a big challenge to the current clinical diagnosis and treatment. In the field of diagnosis, treatment, and rehabilitation of OPHF, traditional Chinese and Western medicine have accumulated rich experience and evidence from evidence-based medicine and achieved favorable outcomes. However, there is still a lack of guidance from a relevant consensus as to how to integrate the advantages of the two medical systems and achieve the integrated diagnosis and treatment. To promote the diagnosis and treatment of OPHF with integrated traditional Chinese and Western medicine, relevant experts from Orthopedic Expert Committee of Geriatric Branch of Chinese Association of Gerontology and Geriatrics, Youth Osteoporosis Group of Orthopedic Branch of Chinese Medical Association, Osteoporosis Group of Orthopedic Surgeon Branch of Chinese Medical Doctor Association, and Osteoporosis Committee of Shanghai Association of Integrated Traditional Chinese and Western Medicine have been organized to formulate Expert consensus on the diagnosis and treatment of osteoporotic proximal humeral fracture with integrated traditional Chinese and Western medicine ( version 2024) by searching related literatures and based on the evidences from evidence-based medicine. This consensus consists of 13 recommendations about the diagnosis, treatment and rehabilitation of OPHF with integrated traditional Chinese medicine and Western medicine, aimed at standardizing, systematizing, and personalizing the diagnosis and treatment of OPHF with integrated traditional Chinse and Western medicine to improve the patients ′ function.

Lipid nanovehicles overcome barriers to systemic RNA delivery: Lipid components, fabrication methods, and rational design

Lipid nanovehicles are currently the most advanced vehicles used for RNA delivery, as demonstrated by the approval of patisiran for amyloidosis therapy in 2018. To illuminate the unique superiority of lipid nanovehicles in RNA delivery, in this review, we first introduce various RNA therapeutics, describe systemic delivery barriers, and explain the lipid components and methods used for lipid nanovehicle preparation. Then, we emphasize crucial advances in lipid nanovehicle design for overcoming barriers to systemic RNA delivery. Finally, the current status and challenges of lipid nanovehicle-based RNA therapeutics in clinical applications are also discussed. Our objective is to provide a comprehensive overview showing how to utilize lipid nanovehicles to overcome multiple barriers to systemic RNA delivery, inspiring the development of more high-performance RNA lipid nanovesicles in the future.

Construction and experimental research of atrophic bone nonunion organoid on chip based on vascularization mechanism / 中华骨科杂志

Objective:To design and construct a bone nonunion organoid on chip and explore the mechanism of aseptic bone nonunion.Methods:First a semi-open microfluidic chip was designed, on which human bone marrow mesenchymal stromal cells (BMSC), human fetal lung fibroblast 1, (HFL1) and human umbilical vein endothelial cells (HUVEC) were co-cultured, and a three-dimensional organ on chip system was established. Different proportions of HFL1 and HUVEC were co-cultured with BMSC, which were divided into the control group (HFL1∶HUVEC=1∶1), the fibrosis group (HFL1∶HUVEC=3∶1) and the vascularization group (HFL1∶HUVEC=1∶3). The osteogenic differentiation of BMSC was observed by alkaline phosphatase (ALP) and Alizarin red staining. The transcription level of osteogenic marker genes SP7, RUNX2, ALPL, and BGLAP, and vascularization related genes KDR and VWF were analyzed by qPCR. The expression levels of RUNX2 and ALP were determined by Western Blot. Results:In the co-culture system of BMSCs, HFL1, and HUVECs, BMSCs exhibited normal growth and apparent biomineralization behavior. Endothelial cells were capable of forming structured vascular networks, confirming the successful establishment of the system. Compared to the baseline group, the fibrotic group showed no significant decrease in BMSC osteogenic differentiation. The relative expression levels of the mineralization marker genes ALPL and BGLAP were 0.55±0.19 ( P<0.001) and 0.42±0.27 ( P<0.001), respectively. Vascularization genes KDR and VWF were downregulated, with relative expression levels of 0.49±0.17 ( P<0.001) and 0.49±0.21 ( P<0.001). In contrast, in the vascularized group, BMSC osteogenic differentiation genes SP7, RUNX2, ALPL, and BGLAP were upregulated, with relative expression levels of 2.91±0.52 ( P<0.001), 3.83±1.87 ( P<0.001), 3.22±1.29 ( P<0.001), and 5.21±1.46 ( P<0.001), respectively. Vascularization genes KDR and VWF were also upregulated, with relative expressions of 8.24±2.84 ( P<0.001) and 5.32±1.67 ( P<0.001). Western blot results indicated increased expression of RUNX2 and ALP in the vascularized group and decreased expression in the fibrotic group. Conclusion:The bone nonunion organoid on chip could partially simulate the local microenvironment of bone nonunion. Fibrosis may lead to a significant decrease in bone formation ability and vascularization level, which might be an important reason for the occurrence of aseptic bone nonunion.

Chinese expert consensus on the diagnosis and treatment of osteoporotic periarticular fracture of the shoulder in the elderly (version 2023) / 中华创伤杂志

Periarticular fracture of the shoulder is a common type of fractures in the elderly. Postoperative adverse events such as internal fixation failure, humeral head ischemic necrosis and upper limb dysfunction occur frequently, which seriously endangers the exercise and health of the elderly. Compared with the fracture with normal bone mass, the osteoporotic periarticular fracture of the shoulder is complicated with slow healing and poor rehabilitation, so the clinical management becomes more difficult. At present, there is no targeted guideline or consensus for this type of fracture in China. In such context, experts from Youth Osteoporosis Group of Chinese Orthopedic Association, Orthopedic Expert Committee of Geriatrics Branch of Chinese Association of Gerontology and Geriatrics, Osteoporosis Group of Youth Committee of Chinese Association of Orthopedic Surgeons and Osteoporosis Committee of Shanghai Association of Chinese Integrative Medicine developed the Chinese expert consensus on the diagnosis and treatment of osteoporotic periarticular fracture of the shoulder in the elderly ( version 2023). Nine recommendations were put forward from the aspects of diagnosis, treatment strategies and rehabilitation of osteoporotic periarticular fracture of the shoulder, hoping to promote the standardized, systematic and personalized diagnosis and treatment concept and improve functional outcomes and quality of life in elderly patients with osteoporotic periarticular fracture of the shoulder.

Guideline for the diagnosis and treatment of chronic refractory wounds in orthopedic trauma patients (version 2023) / 中华创伤杂志

Chronic refractory wound (CRW) is one of the most challengeable issues in clinic due to complex pathogenesis, long course of disease and poor prognosis. Experts need to conduct systematic summary for the diagnosis and treatment of CRW due to complex pathogenesis and poor prognosis, and standard guidelines for the diagnosis and treatment of CRW should be created. The Guideline forthe diagnosis and treatment of chronic refractory wounds in orthopedic trauma patients ( version 2023) was created by the expert group organized by the Chinese Association of Orthopedic Surgeons, Chinese Orthopedic Association, Chinese Society of Traumatology, and Trauma Orthopedics and Multiple Traumatology Group of Emergency Resuscitation Committee of Chinese Medical Doctor Association after the clinical problems were chosen based on demand-driven principles and principles of evidence-based medicine. The guideline systematically elaborated CRW from aspects of the epidemiology, diagnosis, treatment, postoperative management, complication prevention and comorbidity management, and rehabilitation and health education, and 9 recommendations were finally proposed to provide a reliable clinical reference for the diagnosis and treatment of CRW.

Application of the "three-in-one" bone repair strategy in the treatment of osteoporotic fractures / 中华创伤杂志

Osteoporotic fractures secondary to osteoporosis increase very rapidly in incidence, and have become a major cause of disability and mortality in the elderly population. Currently, there have no standard guidelines for perioperative management, surgery and postoperative rehabilitation, causing multiple complications and poor therapeutic outcome. The authors previously proposed bone repair strategies including active anti-osteoporosis, adequate bone grafting and bone healing acceleration, namely "three-in-one" bone repair strategy. The care steps in osteoporotic fracture surgery inluded perioperative management, operative precaution, and postoperative prevention of secondary fractures. With this in mind, the authors further discussed the detailed application of "three-in-one" bone repair strategy including perioperative active anti-osteoporosis treatment, early rehabilitation training, standardized internal fixation selection, standard bone grafting methods and prevention of secondary complications, so as to promote the standardized treatment of osteoporotic fractures and improve the prognosis.

Expert consensus on diagnosis, prevention and treatment of perioperative lower extremity vein thrombosis in orthopedic trauma patients (2022 edition) / 中华创伤杂志

Lower extremity deep vein thrombosis (DVT) is one of the main complications in patients with traumatic fractures, and for severe patients, the DVT can even affect arterial blood supply, resulting in insufficient limb blood supply. If the thrombus breaks off, pulmonary embolism may occur, with a high mortality. The treatment and rehabilitation strategies of thrombosis in patients with lower extremity fractures have its particularity. DVT in traumatic fractures patients has attracted extensive attention and been largely studied, and the measures for prevention and treatment of DVT are constantly developing. In recent years, a series of thrombosis prevention and treatment guidelines have been updated at home and abroad, but there are still many doubts about the prevention and treatment of DVT in patients with different traumatic fractures. Accordingly, on the basis of summarizing the latest evidence-based medical evidence at home and abroad and the clinical experience of the majority of experts, the authors summarize the clinical treatment and prevention protocols for DVT in patients with traumatic fractures, and make this consensus on the examination and assessment, treatment, prevention and preventive measures for DVT in patients with different fractures so as to provide a practicable approach suitable for China ′s national conditions and improve the prognosis and the life quality of patients.

A new strategy for bone defect repair: bone organoids / 中华创伤杂志

Bone tissue repair has long been a hot topic and difficult issue in the field of regenerative medicine research. Although the rapid development of bone tissue engineering technology significantly accelerates the level of bone repair in recent years, bone regeneration research still faces many challenges such as difficulty in regeneration under pathological condition and unclear regenerative regulatory mechanisms. As a result, the evelopment of bone tissue engineering technology encounters a bottleneck, restricting more researches over bone regeneration and repair. As a novel concept, bone organoids are proposed and constructed in vitro with the help of tissue engineering technology based on biological theory, and can simulate the complex biological functions of bone in vivo. Bone organoids show broad application prospects in the research of bone regeneration, including elucidating regulatory regeneration mechanisms, screening biomaterials and promoting regeneration, etc. In this study, the authors preliminarily discuss the features, construction and value of bone organoids so as to provide new insight for the treatment of bone defect.

Efficacy of modified posterolateral approach combined with medial approach in open reduction and internal fixation of trimalleolar ankle fracture / 中华创伤杂志

Objective:To compare the clinical results of modified posterolateral approach combined medial approach versus traditional posterolateral approach combined with medial approach in open reduction and internal fixation of trimalleolar ankle fracture.Methods:A retrospective cohort study was used to analyze the clinical data of 46 patients with trimalleolar ankle fracture admitted to the First Affiliated Hospital of Naval Military Medical University from June 2013 to June 2019, including 14 males and 32 females, at age of 19-71 years [(49.2±14.9)years]. There were 33 patients with supination-external rotation type IV ankle fracture and 13 with pronation-external rotation type IV ankle fracture according to Lauge-Hansen classification. Open reduction and internal fixation was performed through the modified posterolateral approach combined with medial approach in 25 patients (modified approach group), and through the traditional posterolateral approach combined with medial approach in 21 patients (traditional approach group). The visual analogue score (VAS) at 3 days and 1 week after surgery, fracture healing time, range of ankle flexion and extension and Baird-Jackson score at the final follow-up and postoperative complications (numbness of the affect limb, wound necrosis, etc.) were compared between the two groups.Results:All patients were followed up for 11-21 months [(14.8±2.2)months]. There was no statistical difference in VAS or fracture healing time at 3 days after surgery between the two groups (all P>0.05). The VAS was 3.0 (3.0, 4.0)points in modified approach group at 1 week after surgery, significantly lower than 4.0 (3.0, 5.0)points in traditional approach group ( P<0.05). At the final follow-up, there was no statistical difference in range of ankle plantarflexion between the two groups ( P>0.05), but range of ankle dorsiflexion was significantly greater in modified approach group [(11.8±2.8)°] than that in traditional approach group [(8.1±3.5)°] ( P<0.01). At the final follow-up, Baird-Jackson score was not statistically different between the two groups ( P>0.05). There were 4 patients with numbness and 2 with wound necrosis in traditional approach group, but no numbness or wound necrosis occurred in modified approach group ( P<0.01). Conclusion:Both the modified posterolateral approach combined with medial approach and traditional posterolateral approach combined with medial approach can achieve good clinical results in open reduction and internal fixation of trimalleolar ankle fractures, but the former has advantages of better pain relief, better recovery of ankle dorsiflexion and less complications.

Diagnosis and treatment misunderstandings and "three in one" bone repair strategies in osteoporotic fractures / 中华创伤杂志

Osteoporotic fractures have become major social problems threatening the health of the elderly population in China. Compared with conventional fractures, low bone mass, bone defect and retarded healing issues of osteoporotic fractures contribute to the difficulty in treatment and rehabilitation. Addressing major concerns in clinical settings, the "three in one" bone repair strategy focuses on anti-osteoporosis therapies, appropriate bone graft and fracture healing promotion. The authors summarize misunderstandings in diagnosis and treatment of osteoporotic fractures and repair strategies, expecting to improve prognosis and clinically standardize the treatments for osteoporotic fractures, to further improve therapeutic effect and living quality of the patients.

Challenges and potential solutions in treatment of osteoporotic fracture in China / 中华创伤杂志

The osteoporotic fracture, also known as fragility fracture, occurs due to osteoporosis. With the acceleration of aging in China, the incidence of osteoporotic fracture increases rapidly, which causes significant changes in the spectrum of orthopedic trauma. The osteoporotic fracture has both the commonness and particularity of fracture, which poses challenges to orthopedic surgeons. Meanwhile, the fast improvement of interdisciplinary research and the advancement of basic research in bone metabolism have brought many opportunities to facilitate the treatment of osteoporotic fracture. The authors intend to illustrate the challenges and solutions during the treatment of osteoporotic fracture by elaborating the awareness, fracture assessment, drug development, implant design, postoperative rehabilitation and refracture prevention to establish an improved protocol for the therapy.

Effect and mechanism of bone microenvironment on healing of osteoporotic fractures / 中华创伤杂志

The osteoporotic fracture is characterized by difficult treatment and poor prognosis. The studies of bone biology show that bone microenvironment changes during osteoporotic fractures，such as changes in immune factors，abnormal chemotaxis and differentiation of mesenchymal stem cells（MSCs），decreased estrogen secretion and receptor down-regulation and decreased mechanical sensitivity，which affect the fracture healing process. Current studies have shown that by improving the phenotypic polarization of macrophages，enhancing the chemotactic osteogenic activity of MSCs，supplementing estrogen and improving the biomechanical properties of bone can remodel the balance of bone microenvironment，thereby effectively improve the bone quality. The authors explore the effect and mechanism of bone microenvironment on healing of osteoporotic fractures from the perspectives of changes in bone microenvironment and imbalance of bone microenvironment that affect fracture healing and methods of bone microenvironment reconstruction，so as to provide new ideas for clinical treatment of osteoporotic fractures.

Pay attention to role of bone marrow adipose tissue in the regulation of osteoporotic fracture healing / 中华创伤杂志

The osteoporotic fracture is characterized by a high disability rate，poor internal fixation strength，delayed bone healing，etc.，which greatly affects elderly health，so accelerating fracture healing is the key point of therapeutic strategies. Current researches mainly concentrate in bone formation acceleration and resorption inhibition，but the outcomes turn out to be unsatisfactory under the coupling of osteoblasts and osteoclasts. The accumulation of yellow adipose tissue in the medullary cavity is often arisen in patients with osteoporotic fractures，but its role and mechanism in bone metabolism remain unclear. Bone marrow adipocytes are differentiated from mesenchymal stromal cells and possess unique metabolic and secretory functions involving in energy metabolism，maintenance of hematopoietic microenvironment and regulation of bone metabolism balance. However，the role of bone marrow adipose tissue（BMAT）in osteoporotic fracture healing requires more elucidation. In this study，the authors discuss the key role and molecular mechanism of BMAT in the regulation of bone metabolism and homeostasis，aiming to provid new ideas and targets for the promotion of osteoporotic fracture healing.

Expert consensus on elderly patients with hip fracture under epidemic of novel coronavirus pneumonia / 中华创伤杂志

With the spread of novel coronavirus pneumonia (NCP) in December 2019, the management and rehabilitation of elderly patients with hip fractures and protection of medical staff face new challenges, and need to be adjusted appropriately under this very circumstances. Hip fractures in the elderly account for more than half of osteoporotic fractures. Expert group formulate this consensus so as to make better decision against this epidemic and protect patients' families and medical staff. This consensus elaborates not only epidemic condition of NCP, but also general principles of medical admission, treatment and protection for both medical staff and patients, in order to provide some reference and promote the standardization of clinical diagnosis and treatment of elderly patients with hip fractures under the condition of NCP.

Expert consensus on emergency surgery management for traumatic orthopedics under prevention and control of novel coronavirus pneumonia / 中华创伤杂志

Since December 2019, novel coronavirus pneumonia (NCP) has been reported in Wuhan, Hubei Province, and spreads rapidly to all through Hubei Province and even to the whole country. The virus is 2019 novel coronavirus (2019-nCoV), never been seen previously in human, but all the population is generally susceptible. The virus spreads through many ways and is highly infectious, which brings great difficulties to the prevention and control of NCP. Based on the needs of orthopedic trauma patients for emergency surgery and review of the latest NCP diagnosis and treatment strategy and the latest principles and principles of evidence-based medicine in traumatic orthopedics, the authors put forward this expert consensus to systematically standardize the clinical pathway and protective measures of emergency surgery for orthopedic trauma patients during prevention and control of NCP and provide reference for the emergency surgical treatment of orthopedic trauma patients in hospitals at all levels.