Osteoporosis is an emerging threat characterized by systemic damage to bone mass and microarchitecture leading to fragility fractures.Exosomes are nanosized vesicular particles secreted by cells into the extracellular compartment with biological activities similar to those of their cell of origin and play an important role in intercellular communication processes.Exosomes from multiple cell sources are involved in the regulation of bone-related cell proliferation and differentiation during bone metabolism,and have the advantages of high stability,non-immunogenicity and strong targeting ability,which make up for the shortcomings of traditional drug and stem cell therapies.Exosomes secreted from bone marrow mesenchymal stem cells(MSCs)can promote bone regeneration and improve morphology,biomechanics and histological damage,and exosomes derived from bone marrow mesenchymal stem cells(BMSCs)in the mechanical microenvironment are more effective in inducing osteogenesis,significantly enhancing the osteogenic effect of BMSCs and promoting bone regeneration.Therefore,this article provides a review on the mechano-sensitivity of MSCs,mechanical responsive functionalized exosomes of MSCs,and explores their potential role in the treatment of osteoporosis.

OBJECTIVE: To review the research progress of design of bone scaffolds with different single cell structures. METHODS: The related literature on the study of bone scaffolds with different single cell structures at home and abroad in recent years was extensively reviewed, and the research progress was summarized. RESULTS: The single cell structure of bone scaffold can be divided into regular cell structure, irregular cell structure, cell structure designed based on topology optimization theory, and cell structure designed based on triply periodic minimal surface. Different single cell structures have different structural morphology and geometric characteristics, and the selection of single cell structure directly determines the mechanical properties and biological properties of bone scaffold. It is very important to choose a reasonable cell structure for bone scaffold to replace the original bone tissue. CONCLUSION Bone scaffolds have been widely studied, but there are many kinds of bone scaffolds at present, and the optimization of single cell structure should be considered comprehensively, which is helpful to develop bone scaffolds with excellent performance and provide effective support for bone tissue.
Bone and Bones ; Tissue Scaffolds

OBJECTIVE: To summarize the influence of microstructure on performance of triply-periodic minimal surface (TPMS) bone scaffolds. METHODS: The relevant literature on the microstructure of TPMS bone scaffolds both domestically and internationally in recent years was widely reviewed, and the research progress in the imfluence of microstructure on the performance of bone scaffolds was summarized. RESULTS: The microstructure characteristics of TPMS bone scaffolds, such as pore shape, porosity, pore size, curvature, specific surface area, and tortuosity, exert a profound influence on bone scaffold performance. By finely adjusting the above parameters, it becomes feasible to substantially optimize the structural mechanical characteristics of the scaffold, thereby effectively preempting the occurrence of stress shielding phenomena. Concurrently, the manipulation of these parameters can also optimize the scaffold's biological performance, facilitating cell adhesion, proliferation, and growth, while facilitating the ingrowth and permeation of bone tissue. Ultimately, the ideal bone fusion results will obtain. CONCLUSION The microstructure significantly and substantially influences the performance of TPMS bone scaffolds. By deeply exploring the characteristics of these microstructure effects on the performance of bone scaffolds, the design of bone scaffolds can be further optimized to better match specific implantation regions.
Tissue Scaffolds/chemistry* ; Tissue Engineering/methods* ; Bone and Bones ; Porosity

Fibrodysplasia ossificans progressiva(FOP) is a rare congenital disease characterized by progressive heterotopic ossification, causing severe immobility with multi-system involvement. The relatively low incidence rate and incomplete knowledge among clinicians of the disease often result in misuse of invasive procedures or surgical treatment, leading to the progression of heterotopic ossification. To promote the knowledge of FOP, this article presents a comprehensive review involving epidemiology, pathological mechanisms, clinical features, diagnosis, and management of the FOP.

Objective:To investigate gender differences in arterial velocity pulse index(AVI), which is an indicator of vascular stiffness, across various age groups.Additionally, the study will also examine the risk factors associated with AVI.Methods:This cross-sectional study enrolled 4311 patients with an average age of 57.8±12.8 years at Jiading Branch of Shanghai First People's Hospital between August 2020 and September 2021.Patients were divided into three groups based on age: young(<45 years old, n=755), middle-aged(45-59 years old, n=1260), and elderly(≥60 years old, n=2 296). The AVI of the subject was obtained using the cuff oscillation wave method.The subject's AVI was acquired using the cuff oscillation wave.High AVI, indicating arteriosclerosis, was defined as AVI≥33.The subjects were then divided into two groups: the high AVI group(122 cases)and the normal AVI group(4 189 cases).Results:The ankle-brachial index(AVI)was found to be 12.8±3.7, 17.5±5.7, and 19.8±6.5 in the young, middle-aged, and elderly groups, respectively.The study revealed that AVI increased with age( Ftrend=767.819, P<0.01). Additionally, the incidence of high AVI in middle-aged women was found to be(2.8% or 20/722), which was higher than that in men 0.9%(5/538)in the same age group.This difference was statistically significant( χ2=5.371, P<0.05). The results of the multivariate logistic regression analysis indicate that being overweight, having a higher height, and a pulse rate greater than 80 BPM are protective factors in preventing a high incidence of AVI.The odds ratios( OR)with 95% confidence intervals( CI)for these factors were 0.468(0.317-0.690), 0.926(0.895-0.958), and 0.143(1.026-2.432), respectively, all with a P-value less than 0.01.On the other hand, old age, systolic blood pressure of 140 mmHg or higher, and diastolic blood pressure of 90 mmHg or higher were identified as risk factors for AVI.The ORs with 95% CIs for these factors were 2.119(1.322-3.396), 6.652(4.136-10.699), and 1.580(1.026-2.432), respectively, all with a P- value less than 0.05l. Conclusions:Arterial stiffness, as measured by the ankle-brachial index(ABI), tends to increase with age.In middle-aged subjects, women have a higher incidence of high ABI than men.Independent risk factors for high ABI include age and increased blood pressure, while factors such as overweight and height may affect the measured value of ABI.

Femoral fracture is a common type of fracture in clinical practice, and poor fracture reduction may lead to malunion and dysfunction. At present, traditional reduction with manipulation and intramedullary nailing are the mainstream treatments, but there exist problems such as X-ray exposure or poor reduction. Fracture reduction robots are of positive significance in improving the safety of surgical treatment of femur fracture, avoiding repetitive operations and poor alignment, and shortening the patients′ postoperative recovery time. Navigation algorithm is the key to achieve the function of femoral repositioning. Understanding the advantages and disadvantages that various types of navigation algorithms demonstrated in femoral reduction applications is important for giving full play to the value of fracture reduction robots in femoral reduction. Therefore, the authors reviewed the research progress in existing robot navigation algorithms applied in femoral fracture repositioning from the following four aspects, including image alignment algorithm, algorithm for establishing the target pose of femoral repositioning, algorithm for compensating the mechanical error, and algorithm for path planning, hoping to provide a reference for the application and research of navigation algorithms of fracture reduction robots.

Bone defects, often accompanied by osteomyelitis, soft tissue contusions, etc, are facing lengthy treatment process and slow healing, seriously jeopardizing the structural integrity of the human bone tissue. Currently, the main treatment for bone defects involves autologous or allogeneic bone transplant. However, autologous bone transplant poses problems, including long surgical duration, increased pain and complications such as infections. Additionally, immune rejection reactions also limit the effectiveness of allogeneic bone transplant of the same species. Bone scaffolds have become a potential alternative for bone transplant, but problems such as sharp edges of the scaffolds and poor compatibility with human tissues exist. Triply periodic minimal surface (TPMS), with an average curvature of zero has lower levels of stress concentration and the ability to be precisely expressed with mathematical formulas, compared with other structures. Its application in bone scaffolds attracts much attention, but there is currently a lack of comprehensive understanding of the impacts of different types of TPMS on the performance of bone scaffolds. With this purpose, the authors reviewed the research progress in the impacts of different types of TPMS on the performance of bone scaffolds, providing a reference for the construction of bone scaffolds.

Objective To compare the outcomes of operative with non-operative treatment for thoracolumbar burst fracture without neurological deficit using Meta-analysis.Methods Electronic database were searched from inception to February 2014 by two independent reviewers,including Pubmed Medline,Excerpta Medica Database (Embase),Cochrane Central Register of Controlled Trials,Chinese Biology Medicine (CBM),Chinese Wanfang Database,and China National Knowledge Infrastructure (CNKI).Inclusion and exclusion criteria were applied to select the studies.Quality appraisal and data extraction were based on Cochrane Collaboration guidelines.Results Two randomized controlled trials (RCTs),which reported outcomes for 79 patients (41 with operative treatment and 38 with nonoperative treatment) at a follow-up of two years or more were included.Between-study heterogeneity was found to be significant,for one reported better results in surgery group concerning pain relief,function recovery and returning to work.However,opposite results were found in another trial.Meta-analysis showed surgery led to higher complication rates (RR =2.85,95％ CI 0.83-9.75),including subsequent surgery (RR =8.39,95％ CI 1.12-62.87).Conclusion Operative and nonoperative managements produce similar results with respect to pain relief,function regain,and returning to work when performed for thoracolumbar burst fractures without neurologic deficit,but operation is often associated with more complications.

Objective To assess the relationship between reconstruction of coronal trunk shift and changes of unfused segments after selective posterior thoracolumbar/lumbar curves fusion for idiopathic scoliosis.Methods Radiographic data of patients with thoracolumbar/lumbar idiopathic scoliosis who underwent selective posterior correction at our hospital from October 2005 to October 2011 with a minimum of 2 year follow-up period was retrospectively analyzed.Posteroanterior and lateral radiographs of the whole spine before surgery,after surgery and at the last follow-up were performed.Changes of coronal trunk shift during follow-up period were observed and multiple linear regression analysis was performed to determine its relationship with changes of upper thoracic curve,main thoracic curve,lumbar curve,distal unfused segments and coronal sacral inclination.Results Thirty-seven patients with 4 males and 33 females were included in this study.The average age was 14.6±2.0 years (range,12-20 years).The mean follow-up period was 3.6 years (range,2-8.9 years).The mean preoperative Cobb angles of lumbar and thoracic curve were 44.2° and 25.2°,respectively.At the last follow-up,they were corrected to 10.3° and 13.6°,indicating 75.7％ and 44.9％ correction rate,respectively.The pre-and post-operative mean trunk shifts were 2.2 cm and 2.0 cm with no significant differences.At the last follow-up,it compensated to 0.9 cm,which showed significant differences compared with that of postoperation.Linear regression analysis suggested that trunk shift changes during follow-up period were only correlated with changes of distal unfused segments.The regression equation could be described as Changes of trunk shift (cm) =1.248 7+0.137 8×Changes of distal unfused segments (°).Conclusion The reconstruction of coronal trunk balance is mainly compensated by distal unfused segments after selective posterior correction for thoracolumbar/lumbar idiopathic scoliosis.Although preserved most of its levels,unfused thoracic segments do not play an important role in the reconstruction of trunk shift.

Objective To evaluate the efficacy and safety of thromboprophylaxis with low molecular weight heparin after lumbar decompressive surgery.Methods Between January 2004 and April 2011,patients who had undergone lumbar decompressive surgery and had high or very high risk of venous thrombosis were selected.All patients received subcutaneous injection of low molecular weight heparin (Fraxiparine),starting at 6 hours after surgery with a half dose and subsequently once every 24 hours with full dose until discharge.When 24-hour drainage volume was less than 50 ml,the drainage tube was removed 2 hours prior to low molecular weight heparin administration.The occurrences of deep venous thrombosis (DVT),pulmonary embolism (PE),bleeding complications and side effects were recorded.Results Seventy eight patients were enrolled in the study.The average time of drug use was 8.5 days.No symptomatic DVT,PE and major bleeding events occurred.Drainage tube was placed in all patients except 3 patients with lumbar disc herniation.The mean total drainage volume was (319.5±218.5) ml,and the average time from operation to removal of drainage tube was (43.2±14.4) hours.Incision site ecchymosis occurred in 1 patient,incision bleeding in 1 patient,mild elevation in hepatic aminotransferase levels in 4 patients,and mild anaphylaxis in 1 patient.Conclusion It is effective and safe to prevent VTE with low molecular weight heparin for patients with high or very high risk of venous thrombosis after lumbar decompressive surgery.