The key to managing fracture is to achieve stable internal fixation,and currently,biologically and mechanically appropriate internal fixation devices are urgently needed.With excellent biocompatibility and corrosion r...The key to managing fracture is to achieve stable internal fixation,and currently,biologically and mechanically appropriate internal fixation devices are urgently needed.With excellent biocompatibility and corrosion resistance,titanium–niobium alloys have the potential to become a new generation of internal fixation materials for fractures.However,the role and mechanism of titanium–niobium alloys on promoting fracture healing are still undefined.Therefore,in this study,we systematically evaluated the bone-enabling properties of Ti45Nb via in vivo and in vitro experiments.In vitro,we found that Ti45Nb has an excellent ability to promote MC3T3-E1 cell adhesion and proliferation without obvious cytotoxicity.Alkaline phosphatase(ALP)activity and alizarin red staining and semiquantitative analysis showed that Ti45Nb enhanced the osteogenic differentiation of MC3T3-E1 cells compared to the Ti6Al4V control.In the polymerase chain reaction experiment,the expression of osteogenic genes in the Ti45Nb group,such as ALP,osteopontin(OPN),osteocalcin(OCN),type 1 collagen(Col-1)and runt-related transcription factor-2(Runx2),was significantly higher than that in the control group.Meanwhile,in the western blot experiment,the expression of osteogenic-related proteins in the Ti45Nb group was significantly increased,and the expression of PI3K–Akt-related proteins was also higher,which indicated that Ti45Nb might promote fracture healing by activating the PI3K–Akt signaling pathway.In vivo,we found that Ti45Nb implants accelerated fracture healing compared to Ti6Al4V,and the biosafety of Ti45Nb was confirmed by histological evaluation.Furthermore,immunohistochemical staining confirmed that Ti45Nb may promote osteogenesis by upregulating the PI3K/Akt signaling pathway.Our study demonstrated that Ti45Nb exerts an excellent ability to promote fracture healing as well as enhance osteoblast differentiation by activating the PI3K/Akt signaling pathway,and its good biosafety has been confirmed,which indicates its clinical translation potential.展开更多
Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H ...Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis.Here,we show that metformin accelerated fracture healing in both osteoporotic and normal mice.Moreover,metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing.Mechanistically,metformin increased the expression of HIF-1α,an important positive regulator of type H vessel formation,by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells(HMECs).The results of HIF-1αor YAP1/TAZ interference in hypoxia-cultured HMECs using si RNA further suggested that the enhancement of HIF-1αand its target genes by metformin is primarily through YAP1/TAZ inhibition.Finally,overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair.In summary,our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.展开更多
Maturation of the 3′end of almost all eukaryotic messenger RNAs(m RNAs)requires cleavage and polyadenylation.Most mammalian m RNAs are polyadenylated at different sites within the last exon,generating alternative pol...Maturation of the 3′end of almost all eukaryotic messenger RNAs(m RNAs)requires cleavage and polyadenylation.Most mammalian m RNAs are polyadenylated at different sites within the last exon,generating alternative polyadenylation(APA)isoforms that have the same coding region but distinct 3′untranslated regions(UTRs).The 3′UTR contains motifs that regulate m RNA metabolism;thus,changing the 3′UTR length via APA can significantly affect gene expression.Endochondral ossification is a central process in bone healing,but the impact of APA on gene expression during this process is unknown.Here,we report the widespread occurrence of APA,which impacts multiple pathways that are known to participate in bone healing.Importantly,the progression of endochondral ossification involves global 3′UTR shortening,which is coupled with an increased abundance of shortened transcripts relative to other transcripts;these results highlight the role of APA in promoting gene expression during endochondral bone formation.Our mechanistic studies of transcripts that undergo APA in the fracture callus revealed an intricate regulatory network in which APA enhances the expression of the collagen,type I,alpha 1(Col1a1)and Col1a2 genes,which encode the 2 subunits of the abundantly expressed protein collagen 1.APA exerts this effect by shortening the 3′UTRs of the Col1a1 and Col1a2 m RNAs,thus removing the binding sites of mi R-29a-3p,which would otherwise strongly promote the degradation of both transcripts.Taken together,our study is the first to characterize the crucial roles of APA in regulating the 3′UTR landscape and modulating gene expression during fracture healing.展开更多
In vertebrates,bone is considered an osteoimmune system which encompasses functions of a locomotive organ,a mineral reservoir,a hormonal organ,a stem cell pool and a cradle for immune cells.This osteoimmune system is ...In vertebrates,bone is considered an osteoimmune system which encompasses functions of a locomotive organ,a mineral reservoir,a hormonal organ,a stem cell pool and a cradle for immune cells.This osteoimmune system is based on cooperatively acting bone and immune cells,cohabitating within the bone marrow.They are highly interdependent,a fact that is confounded by shared progenitors,mediators,and signaling pathways.Successful fracture healing requires the participation of all the precursors,immune and bone cells found in the osteoimmune system.Recent evidence demonstrated that changes of the immune cell composition and function may negatively influence bone healing.In this review,first the interplay between different immune cell types and osteoprogenitor cells will be elaborated more closely.The separate paragraphs focus on the specific cell types,starting with the cells of the innate immune response followed by cells of the adaptive immune response,and the complement system as mediator between them.Finally,a brief overview on the challenges of preclinical testing of immunebased therapeutic strategies to support fracture healing will be given.展开更多
BACKGROUND There is still no consensus on which concentration of mesenchymal stem cells(MSCs)to use for promoting fracture healing in a rat model of long bone fracture.AIM To assess the optimal concentration of MSCs f...BACKGROUND There is still no consensus on which concentration of mesenchymal stem cells(MSCs)to use for promoting fracture healing in a rat model of long bone fracture.AIM To assess the optimal concentration of MSCs for promoting fracture healing in a rat model.METHODS Wistar rats were divided into four groups according to MSC concentrations:Normal saline(C),2.5×10^(6)(L),5.0×10^(6)(M),and 10.0×10^(6)(H)groups.The MSCs were injected directly into the fracture site.The rats were sacrificed at 2 and 6 wk post-fracture.New bone formation[bone volume(BV)and percentage BV(PBV)]was evaluated using micro-computed tomography(CT).Histological analysis was performed to evaluate fracture healing score.The protein expression of factors related to MSC migration[stromal cell-derived factor 1(SDF-1),transforming growth factor-beta 1(TGF-β1)]and angiogenesis[vascular endothelial growth factor(VEGF)]was evaluated using western blot analysis.The expression of cytokines associated with osteogenesis[bone morphogenetic protein-2(BMP-2),TGF-β1 and VEGF]was evaluated using real-time polymerase chain reaction.RESULTS Micro-CT showed that BV and PBV was significantly increased in groups M and H compared to that in group C at 6 wk post-fracture(P=0.040,P=0.009;P=0.004,P=0.001,respectively).Significantly more cartilaginous tissue and immature bone were formed in groups M and H than in group C at 2 and 6 wk post-fracture(P=0.018,P=0.010;P=0.032,P=0.050,respectively).At 2 wk post fracture,SDF-1,TGF-β1 and VEGF expression were significantly higher in groups M and H than in group L(P=0.031,P=0.014;P<0.001,P<0.001;P=0.025,P<0.001,respectively).BMP-2 and VEGF expression were significantly higher in groups M and H than in group C at 6 wk postfracture(P=0.037,P=0.038;P=0.021,P=0.010).Compared to group L,TGF-β1 expression was significantly higher in groups H(P=0.016).There were no significant differences in expression levels of chemokines related to MSC migration,angiogenesis and cytokines associated with osteogenesis between M and H groups at 2 and 6 wk post-fracture.CONCLUSION The administration of at least 5.0×10^(6)MSCs was optimal to promote fracture healing in a rat model of long bone fractures.展开更多
Objective:To study the effects of Shang Ke Jie Gu tablet on fracture healing in rabbits.Methods:40 New Zealand rabbits,half male and half female,were randomly divided into two groups:normal saline group(N group)and Sh...Objective:To study the effects of Shang Ke Jie Gu tablet on fracture healing in rabbits.Methods:40 New Zealand rabbits,half male and half female,were randomly divided into two groups:normal saline group(N group)and Shang Ke Jie Gu tablet group(S group).Each group consisted of 20 rabbits.Left radial fracture models in upper and middle sections were made in rabbits and then intra-gastric administration was given.Five rabbits in each group were killed on the 10 th,20^(th),30^(th) and 40^(th) day after surgery,left radius was taken to get an X-ray.The degree of healing was assessed by the evaluation criteria of Shanghai Orthopaedics Institute.Results:The degree of fracture healing in S group was higher in the comparison with that in N group.Conclusions:Shang Ke Jie Gu tablet might affect endochondral ossification during fracture healing of rabbits,and promote porosis and fracture healing.展开更多
To investigate the impact of different kinds of nerve injuries of early-stage fracture healing.Methods Three groups of rats were included in the experiment among which group 1 was inflicted with femoral fracture and T...To investigate the impact of different kinds of nerve injuries of early-stage fracture healing.Methods Three groups of rats were included in the experiment among which group 1 was inflicted with femoral fracture and T10 spinal cord transsection (SCI),group 2 was inflicted with femoral and peripheral nerve resection (PNR),and group 3 with simple femoral fracture as control group.Two weeks after operation the femoral bones were collected for X-ray checking and 2 more weeks later X-ray checking was performed again followed by pathomorphologic exams.Results X-ray result showed no massive calluses in the bones in the 2nd week postoperatively,while in the 4th week,callus appeared with larger size in group 3 than that of group 1 and with smaller size than that of group 2.It was the same with the result of pathomorphologic examining.Cortical bone bridges between fracture point and osteiod were also found in group 2 and there were less normal blood vessels and worse bone remodeling than that of group 3.There were relatively immature calluses with more fibroblast-like cells and disordered bone structure in group 2.Group 3 showed normal healing process and callus structure.Conclusion Early-stage bone fracture healing can be influenced significantly by different kinds of nerve injuries.6 refs,6 figs.展开更多
Teriparatide is a recombinant form of the biologicallyactive component of Parathyroid hormone. It has been shown to increase bone mass and prevent fractures in osteoporotic bone. It is licensed by the Food and Drug Ad...Teriparatide is a recombinant form of the biologicallyactive component of Parathyroid hormone. It has been shown to increase bone mass and prevent fractures in osteoporotic bone. It is licensed by the Food and Drug Administration for the treatment of Osteoporosis. Over the last decade, a growing body of evidence has accumulated suggesting a role for Teriparatide in the management of fractures. Studies in both normal and delayed healing models have shown improvement in callus volume and mineralisation, bone mineral content, rate of successful union and strength at fracture sites. However most of these results have been derived from animal studies. The majority of this research on humans has comprised low level evidence, with few randomised controlled trials, many case reports and case series. Nevertheless, the results from these studies seem to support research from animal models. This has led to a growing number of clinicians using Teriparatide "off license" to treat fractures and non-unions in their patients. This review presents a critical appraisal of the current evidence supporting the use of Teriparatide for fracture healing, delayed unions and non unions and in the setting of osteoporotic fractures, the studies producing this evidence and their transferability to human beings.展开更多
Successful fracture healing requires the simultaneous regeneration of both the bone and vasculature;mesenchymal stem cells (MSCs) are directed to replace the bone tissue, while endothelial progenitor cells (EPCs) form...Successful fracture healing requires the simultaneous regeneration of both the bone and vasculature;mesenchymal stem cells (MSCs) are directed to replace the bone tissue, while endothelial progenitor cells (EPCs) form the new vasculature that supplies blood to the fracture site. In the elderly, the healing process is slowed, partly due to decreased regenerative function of these stem and progenitor cells. MSCs from older individuals are impaired with regard to cell number, proliferative capacity, ability to migrate, and osteochondrogenic differentiation potential. The proliferation, migration and function of EPCs are also compromised with advanced age. Although the reasons for cellular dysfunction with age are complex and multidimensional, reduced expression of growth factors, accumulation of oxidative damage from reactive oxygen species, and altered signaling of the Sirtuin-1 pathway are contributing factors to aging at the cellular level of both MSCs and EPCs. Because of these geriatric-specific issues, effective treatment for fracture repair may require new therapeutic techniques to restore cellular function. Some suggested directions for potential treatments include cellular therapies, pharmacological agents, treatments targeting age-related molecular mechanisms, and physical therapeutics. Advanced age is the primary risk factor for a fracture, due to the low bone mass and inferior bone quality associated with aging;a better understanding of the dysfunctional behavior of the aging cell will provide a foundation for new treatments to decrease healing time and reduce the development of complications during the extended recovery from fracture healing in the elderly.展开更多
Osteoporosis(OP)is a common age-related disease characterized by a deterioration of bone mass and structure that predisposes patients to fragility fractures.Pharmaceutical therapies that promote anabolic bone formatio...Osteoporosis(OP)is a common age-related disease characterized by a deterioration of bone mass and structure that predisposes patients to fragility fractures.Pharmaceutical therapies that promote anabolic bone formation in OP patients and OP-induced fracture are needed.We investigated whether a neutralizing antibody against Siglec-15 can simultaneously inhibit bone resorption and stimulate bone formation.We found that the multinucleation of osteoclasts was inhibited in SIGLEC-15 conditional knockout mice and mice undergoing Siglec-15 neutralizing antibody treatment.The secretion of platelet-derived growth factor-BB(PDGF-BB),the number of tartrate-resistant acid phosphatase-positive(TRAP+)mononuclear cells,and bone formation were significantly increased in the SIGLEC-15 conditional knockout mice and antibody-treated mice.The anabolic effect of the Siglec-15 neutralizing antibody on bone formation was blunted in mice with Pdgfb deleted in TRAP-1"cells.These findings showed that the anabolic effect of the Siglec-15 neutralizing antibody was mediated by elevating PDGF-BB production of TRAP4 mononuclear cells.To test the therapeutic potential of the Siglec-15 neutralizing antibody,we injected the antibody in an ovariectomy-induced osteoporotic mouse model,which mimics postmenopausal osteoporosis in women,and in two fracture healing models because fracture is the most serious health consequence of osteoporosis.The Siglec-15 neutralizing antibody effectively reduced bone resorption and stimulated bone formation in estrogen deficiency-induced osteoporosis.Of note,the Siglec-15 neutralizing antibody promoted intramembranous and endochondral ossification at the damaged area of cortical bone in fracture healing mouse models.Thus,the Siglec-15 neutralizing antibody shows significant translational potential as a novel therapy for OP and bone fracture.展开更多
There remain unmet clinical needs for safe and effective bone anabolic therapies to treat aging-related osteoporosis and to improve fracture healing in cases of nonunion or delayed union. Wnt signaling has emerged as ...There remain unmet clinical needs for safe and effective bone anabolic therapies to treat aging-related osteoporosis and to improve fracture healing in cases of nonunion or delayed union. Wnt signaling has emerged as a promising target pathway for developing novel bone anabolic drugs. Although neutralizing antibodies against the Wnt antagonist sclerostin have been tested,Wnt ligands themselves have not been fully explored as a potential therapy. Previous work has demonstrated Wnt7b as an endogenous ligand upregulated during osteoblast differentiation, and that Wnt7b overexpression potently stimulates bone accrual in the mouse. The earlier studies however did not address whether Wnt7b could promote bone formation when specifically applied to aged or fractured bones. Here we have developed a doxycycline-inducible strategy where Wnt7b is temporally induced in the bones of aged mice or during fracture healing. We report that forced expression of Wnt7b for 1 month starting at 15 months of age greatly stimulated trabecular and endosteal bone formation, resulting in a marked increase in bone mass. We further tested the effect of Wnt7b on bone healing in a murine closed femur fracture model. Induced expression of Wnt7b at the onset of fracture did not affect the initial cartilage formation but promoted mineralization of the subsequent bone callus. Thus, targeted delivery of Wnt7b to aged bones or fracture sites may be explored as a potential therapy.展开更多
Objective:To study the effect of aspirin on healing process of osteoporotic fracture(OPF)in rats.Methods:A total of 50 female Wistar rata aged 3 months were randomly divided into observation group and control group,ca...Objective:To study the effect of aspirin on healing process of osteoporotic fracture(OPF)in rats.Methods:A total of 50 female Wistar rata aged 3 months were randomly divided into observation group and control group,castration method was adopted to establish the osteoporosis(OP)model.After artificial preparing fractures on the midpoint of left femur,fixing gram needle intramedullary.OPF modeling was complete.Aspirin lavage of 33 mg once a day was adoptde in observation group after modeling,same amount of normal saline was used in the control as placebo.From eash group,selected 5 rats at the 2nd.4th,8th and 12th week after modeling to measure the bone mineral density(BMD)and histogical examination of the fracture callus,radiology observation was conducted at the 8th and 12th week.Left femur biomechanical measurement was taken at the 12th week.Results:BMD values of observation group at each time point were significantly higher than that of the control group after modeling(P<0.05);Histological observation showed that at the 8th week,the endochondral ossification process of observation group was faster than that of observation group,with fuzzy fracture line in observation group and clear fracture line in observtion group;at the 12th week,fracture line disappeared in observation group,fracture line of the control group was fuzzy at the same time;three-point bending load of the left femur in observation group rats was significantly higher than that of control group after12 weeka(P<0.05).Conclusions:Asporin can accelerate the healing of new callus in OPF rats,increase bone density and biomechanics strength,and promote fracture of osteporotic rats.展开更多
BACKGROUND Non-steroidal anti-inflammatory drugs(NSAIDs)are among the most commonly prescribed medications in the United States.Although they are safe and effective means of analgesia for children with broken bones,th...BACKGROUND Non-steroidal anti-inflammatory drugs(NSAIDs)are among the most commonly prescribed medications in the United States.Although they are safe and effective means of analgesia for children with broken bones,there is considerable variation in their clinical use due to persistent concerns about their potentially adverse effect on fracture healing.AIM To assess whether NSAID exposure is a risk factor for fracture nonunion in children.METHODS We systematically reviewed the literature reporting the effect of NSAIDs on bone healing.We included all clinical studies that reported on adverse bone healing complications in children with respect to NSAID exposure.The outcomes of interest were delayed union or nonunion.Study quality was assessed using the Newcastle-Ottawa scale for non-randomized studies.A final table was constructed summarizing the available evidence.RESULTS A total of 120 articles were identified and screened,of which 6 articles were included for final review.Nonunion in children is extremely rare;among the studies included,there were 2011 nonunions among 238822 fractures(0.84%).None of the included studies documented an increased risk of nonunion or delayed bone healing in those children who are treated with NSAIDs in the immediate post-injury or peri-operative time period.Additionally,children are likely to take these medications for only a few days after injury or surgery,further decreasing their risk of adverse side-effects.CONCLUSION This systematic review suggests that NSAIDS can be safely prescribed to pediatric orthopaedic patients absent other contraindications without concern for increased risk of fracture non-union or delayed bone healing.Additional prospective studies are needed focusing on higher risk fractures and elective orthopaedic procedures such as osteotomies and spinal fusion.展开更多
Identification of regulators of osteoblastogenesis that can be pharmacologically targeted is a major goal in combating osteoporosis,a common disease of the elderly population. Here, unbiased kinome RNAi screening in p...Identification of regulators of osteoblastogenesis that can be pharmacologically targeted is a major goal in combating osteoporosis,a common disease of the elderly population. Here, unbiased kinome RNAi screening in primary murine osteoblasts identified cyclin-dependent kinase 5(Cdk5) as a suppressor of osteoblast differentiation in both murine and human preosteoblastic cells. Cdk5 knockdown by si RNA, genetic deletion using the Cre-lox P system, or inhibition with the small molecule roscovitine enhanced osteoblastogenesis in vitro. Roscovitine treatment significantly enhanced bone mass by increasing osteoblastogenesis and improved fracture healing in mice. Mechanistically, downregulation of Cdk5 expression increased Erk phosphorylation, resulting in enhanced osteoblast-specific gene expression. Notably, simultaneous Cdk5 and Erk depletion abrogated the osteoblastogenesis conferred by Cdk5 depletion alone, suggesting that Cdk5 regulates osteoblast differentiation through MAPK pathway modulation. We conclude that Cdk5 is a potential therapeutic target to treat osteoporosis and improve fracture healing.展开更多
Objective:To compare the clinical therapeutic effect of bridge combined internal fixation system and locking compression plate internal fixation in the treatment of displaced midshaft clavicle fractures by emphaticall...Objective:To compare the clinical therapeutic effect of bridge combined internal fixation system and locking compression plate internal fixation in the treatment of displaced midshaft clavicle fractures by emphatically observing fracture healing and shoulder joint function.Methods:Totally 44 elderly patients with Robinson type 2B displaced midshaft clavicle fractures were included from the Department of Orthopaedics,Shenyang Fourth People's Hospital during February 2016 and December 2018,including 23 males and 21 females,mean age(69.8±10.2)years old.The patients were divided into a bridge combined internal fixation system group(bridge group,n=22)and a locking compression plate internal fixation group(plate group,n=22)according to the internal fixation methods.The operation time,intraoperative blood loss,fracture healing time,and postoperative complications were recorded.At 12 months after surgery,the shoulder joint Constant-Murley score and DASH score were used to assess the recovery of joint function.The serum levels of bone turnover biochemical markers procollagen I N-terminal peptide(P1NP),cross-linked Carboxy-terminal telopeptide of typeⅠcollagen(CTX-I),and osteoblast specific factor(OSF)were measured before and 3 months after surgery.Results:The operation time,intraoperative blood loss and fracture healing time of the bridge group were significantly shorter than those of the plate group(P<0.05).Constant scores and DASH scores in the bridge group were significantly better than those of the plate group at 12 months after surgery(P<0.05).Serum levels of CTX-I was significantly decreased,while the P1NP and OSF were significantly increased compared with before surgery in the both groups(P<0.05),and the changes were more obvious in the bridge group(P<0.05).The incidence of complications was similar between the two groups(P<0.05).Conclusion:Compared with the locking plate system,the bridge combined internal fixation system can effectively improve the operation efficiency,have more benefits on fracture healing,better promote the recovery of patients'function,and reduce the failure rate of internal fixation,thus providing a better choice to treat displaced midshaft clavicle fractures by intraoperative internal fixation.展开更多
To observe the safety and effectiveness of a topical herbal agent used to promote fracture healing, a herbal patch containing extracts of three herbs, viz., Flos Carthami, Radix Dipsaci, Rhizoma Rhei and Borneolum Syn...To observe the safety and effectiveness of a topical herbal agent used to promote fracture healing, a herbal patch containing extracts of three herbs, viz., Flos Carthami, Radix Dipsaci, Rhizoma Rhei and Borneolum Syntheticum (an enhancer) was applied on ten subjects with un-displaced fifth metatarsal fractures. Pain scores, foot and ankle function questionnaires and regional swelling were carefully assessed and recorded. Peripheral blood was taken to measure the inflammation cytokines. Assessment checks were performed biweekly to enforce effective patch application and compliance. The results showed that pain improved after two weeks and fracture sites swelling had 20% reduction in thickness when measured with an ultrasonic tool. Foot and ankle functional scores markedly improved after six weeks. Radiological examinations revealed early perfect fracture unions. The topical herbal patch was effective in promoting fracture healing. It was well tolerated by the fracture patients. Larger randomized controlled trials would be indicated.展开更多
Summary: In order to investigate the effect of a new institute-designed absorbable hydroxyapatite microparticles/poly-DL-lactide (HA/PDLLA) fracture fixation devices on experimental fracture healing, 25 rabbits with a...Summary: In order to investigate the effect of a new institute-designed absorbable hydroxyapatite microparticles/poly-DL-lactide (HA/PDLLA) fracture fixation devices on experimental fracture healing, 25 rabbits with a transverse transcondylar osteotomy of the distal femur were fixed in- tramedullary by a HA/PDLLA rod (4. 5 mm in diameter, 30-40 mm in length). The follow-up time lasted 1, 2, 4, 6 and 12 week(s). Roentgenographic, histological and ultrastructural analyses were conducted. The results showed that all osteotomies united within 6 weeks without delay. No accumulation of inflammatory cells was seen. Ultrastructural studies showed that polymorphonuclear neutrophils and macrophages were observed mainly at the 1st week, but only few were noted at the 2nd week. The inflammatory and debridement stages were not prolonged. Large amount of active fibroblasts and some chondroblasts were observed at the 2nd week, suggesting a fibrous callus stage. The main cellularity at 4th week was osteoblasts and osteocytes. Part of osteocytes had already entered the static stage at the 6th week. Our experiment showed that the HA/PDLLA had good biocompatibility, sufficient mechanical strength and caused no delay to the fracture healing.展开更多
The trabecular bone fracture healing differs from diaphyseal fracture healing, in which trabecular bone heals based on intramembraneous ossification. The process includes a small callus formation, then woven bone form...The trabecular bone fracture healing differs from diaphyseal fracture healing, in which trabecular bone heals based on intramembraneous ossification. The process includes a small callus formation, then woven bone forms, it follows by remodeling process to form regular trabecular bone. The objective of this study was to present an energy based model to simulate bone formation and remodeling during trabecular bone fracture healing. This modeling mainly focused on the mechanical factors. The model distinguishes three basic type of tissue: bone, cartilage and soft tissue. In order to determine tissue differentiation a fuzzy controller was proposed. An algorithm was developed to link the fuzzy logic controller to a finite element model (FEM) of trabecular bone. In general, finite element analysis provides input for fuzzy controller. Based on the input data, the fuzzy system selects the type of tissue to build. Strain energy density was used as the mechanical stimulus and a new parameter was incorporated in to the healing process as the remodeling index.展开更多
Following fracture of left tibia in 14 Wistar rats the mitosis and proliferation of various cellular components in callus tissues were studied with ~3H-Thymidine labelling and radioautographic technique. There was acc...Following fracture of left tibia in 14 Wistar rats the mitosis and proliferation of various cellular components in callus tissues were studied with ~3H-Thymidine labelling and radioautographic technique. There was accumulation of silver grains over the nuclei of mesenchymal cells ,endothelial cells of capillaries, fibroblasts and chondrocytes as a result of mitosis and incorporation of the labelling isotopes. Although the osteoblasts and osteocytes could not divide they derived from the mesenchymal cells and osteogenic cells, thus showing silver grains as well. Besides, fat cells and muscle cells likewise revealed silver grains signifying that in fracture healing a number of connective tissue cells underwent mitosis and proliferation.展开更多
Background: In this experimental study, we aimed to determine the possible changes in fracture healing due to denervation and/or nerve ending interpositioning. Methods: 50 Wistar Albino type male rats were divided int...Background: In this experimental study, we aimed to determine the possible changes in fracture healing due to denervation and/or nerve ending interpositioning. Methods: 50 Wistar Albino type male rats were divided into three study groups. A standard transverse diaphysial fracture in the femurs of the same side of all subjects under anesthesia was created and the fracture were fixed intramedullarily. While preserving the structural integrity of the sciatic nerve in the first group, neurectomy to the nerve in the second group was performed. In the third group, following the sciatic nerve cut, the proximal end of the nerve were interposed the fracture line. After a 28-day observational period, the callus formation in the subjects was examined radiologically, biomechanically and histopathologically. Results: Among all groups, the third group subjects showed significant increase in radiological area measurements when they are compared to the second group rats. There was no significant difference in biomechanical measurements of fractured femurs of the three groups. In histopathological evaluations, it was observed that denervation had increased the thickness of the cartilage and the number of the chondrocytes and osteoclasts significantly but decreased the number of fibroblasts compared to the control group. In addition to the denervation nerve ending interpositioning increased the bone thickness and the number of the osteoblasts but decreased the number of the osteoclasts significantly. Conclusions: While radiological observations exhibit that nerve ending interpositioning has resulted more hypertrophic callus formation, histopathological evaluations led us to that denervation created partial (immature) callus formation and nerve ending interpositioning demonstrated larger but immature callus formation.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.81972058,81902194 and 82202680)the Science and Technology Commission of Shanghai Municipality(No.22YF1422900)+3 种基金the Shanghai Municipal Key Clinical Specialty,China(No.shslczdzk06701)the National Facility for Translational Medicine(Shanghai),China(No.TMSZ-2020-207)the Shanghai Engineering Research Center of Orthopedic Innovative Instruments and Personalized Medicine Instruments and Personalized Medicine(No.19DZ2250200)the Key R&D Program of Ningxia,China(Nos.2020BCH01001 and 2021BEG02037).
文摘The key to managing fracture is to achieve stable internal fixation,and currently,biologically and mechanically appropriate internal fixation devices are urgently needed.With excellent biocompatibility and corrosion resistance,titanium–niobium alloys have the potential to become a new generation of internal fixation materials for fractures.However,the role and mechanism of titanium–niobium alloys on promoting fracture healing are still undefined.Therefore,in this study,we systematically evaluated the bone-enabling properties of Ti45Nb via in vivo and in vitro experiments.In vitro,we found that Ti45Nb has an excellent ability to promote MC3T3-E1 cell adhesion and proliferation without obvious cytotoxicity.Alkaline phosphatase(ALP)activity and alizarin red staining and semiquantitative analysis showed that Ti45Nb enhanced the osteogenic differentiation of MC3T3-E1 cells compared to the Ti6Al4V control.In the polymerase chain reaction experiment,the expression of osteogenic genes in the Ti45Nb group,such as ALP,osteopontin(OPN),osteocalcin(OCN),type 1 collagen(Col-1)and runt-related transcription factor-2(Runx2),was significantly higher than that in the control group.Meanwhile,in the western blot experiment,the expression of osteogenic-related proteins in the Ti45Nb group was significantly increased,and the expression of PI3K–Akt-related proteins was also higher,which indicated that Ti45Nb might promote fracture healing by activating the PI3K–Akt signaling pathway.In vivo,we found that Ti45Nb implants accelerated fracture healing compared to Ti6Al4V,and the biosafety of Ti45Nb was confirmed by histological evaluation.Furthermore,immunohistochemical staining confirmed that Ti45Nb may promote osteogenesis by upregulating the PI3K/Akt signaling pathway.Our study demonstrated that Ti45Nb exerts an excellent ability to promote fracture healing as well as enhance osteoblast differentiation by activating the PI3K/Akt signaling pathway,and its good biosafety has been confirmed,which indicates its clinical translation potential.
基金supported by the National Natural Science Foundation of China (Grant Nos.81874006,82172399,81902222,82060395,81902277,82072504,82000845)the Hunan Province Natural Science Foundation of China (Grant Nos.2020JJ4928,2020JJ4897,2021JJ30038,2021JJ40492)the Independent Exploration and Innovation Project of Central South University (Grant Nos.2020zzts255)。
文摘Due to increasing morbidity worldwide,fractures are becoming an emerging public health concern.This study aimed to investigate the effect of metformin on the healing of osteoporotic as well as normal fractures.Type H vessels have recently been identified as a bone-specific vascular subtype that supports osteogenesis.Here,we show that metformin accelerated fracture healing in both osteoporotic and normal mice.Moreover,metformin promoted angiogenesis in vitro under hypoxia as well as type H vessel formation throughout fracture healing.Mechanistically,metformin increased the expression of HIF-1α,an important positive regulator of type H vessel formation,by inhibiting the expression of YAP1/TAZ in calluses and hypoxia-cultured human microvascular endothelial cells(HMECs).The results of HIF-1αor YAP1/TAZ interference in hypoxia-cultured HMECs using si RNA further suggested that the enhancement of HIF-1αand its target genes by metformin is primarily through YAP1/TAZ inhibition.Finally,overexpression of YAP1/TAZ partially counteracted the effect of metformin in promoting type H vessel-induced angiogenesis-osteogenesis coupling during fracture repair.In summary,our findings suggest that metformin has the potential to be a therapeutic agent for fractures by promoting type H vessel formation through YAP1/TAZ inhibition.
基金National Institutes of Health(NIH)R01 DK121327 to R.A.E。
文摘Maturation of the 3′end of almost all eukaryotic messenger RNAs(m RNAs)requires cleavage and polyadenylation.Most mammalian m RNAs are polyadenylated at different sites within the last exon,generating alternative polyadenylation(APA)isoforms that have the same coding region but distinct 3′untranslated regions(UTRs).The 3′UTR contains motifs that regulate m RNA metabolism;thus,changing the 3′UTR length via APA can significantly affect gene expression.Endochondral ossification is a central process in bone healing,but the impact of APA on gene expression during this process is unknown.Here,we report the widespread occurrence of APA,which impacts multiple pathways that are known to participate in bone healing.Importantly,the progression of endochondral ossification involves global 3′UTR shortening,which is coupled with an increased abundance of shortened transcripts relative to other transcripts;these results highlight the role of APA in promoting gene expression during endochondral bone formation.Our mechanistic studies of transcripts that undergo APA in the fracture callus revealed an intricate regulatory network in which APA enhances the expression of the collagen,type I,alpha 1(Col1a1)and Col1a2 genes,which encode the 2 subunits of the abundantly expressed protein collagen 1.APA exerts this effect by shortening the 3′UTRs of the Col1a1 and Col1a2 m RNAs,thus removing the binding sites of mi R-29a-3p,which would otherwise strongly promote the degradation of both transcripts.Taken together,our study is the first to characterize the crucial roles of APA in regulating the 3′UTR landscape and modulating gene expression during fracture healing.
基金Supported by German Research Foundation(DFG)focusing on“Interplay between mononuclear and osteogenic cells during fracture healing in type 2 diabetics”,No.EH 471/2(to Ehnert S)German Research Foundation within the context of the Collaborative Research Center(CRC)1149“Danger Response,Disturbance Factors and Regenerative Potential after Acute Trauma”,No.251293561,C01(to Ignatius A and Fischer V)+1 种基金DFG in context of the CRC 1149,No.251293561,A01 and No.251293561 Z02(to Huber-Lang M)and DFG in the context of the CRC 1149,No.251293561,C07(to Kalbitz M).
文摘In vertebrates,bone is considered an osteoimmune system which encompasses functions of a locomotive organ,a mineral reservoir,a hormonal organ,a stem cell pool and a cradle for immune cells.This osteoimmune system is based on cooperatively acting bone and immune cells,cohabitating within the bone marrow.They are highly interdependent,a fact that is confounded by shared progenitors,mediators,and signaling pathways.Successful fracture healing requires the participation of all the precursors,immune and bone cells found in the osteoimmune system.Recent evidence demonstrated that changes of the immune cell composition and function may negatively influence bone healing.In this review,first the interplay between different immune cell types and osteoprogenitor cells will be elaborated more closely.The separate paragraphs focus on the specific cell types,starting with the cells of the innate immune response followed by cells of the adaptive immune response,and the complement system as mediator between them.Finally,a brief overview on the challenges of preclinical testing of immunebased therapeutic strategies to support fracture healing will be given.
基金the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI),funded by the Ministry of Health&Welfare,Republic of Korea,No.HI20C1405。
文摘BACKGROUND There is still no consensus on which concentration of mesenchymal stem cells(MSCs)to use for promoting fracture healing in a rat model of long bone fracture.AIM To assess the optimal concentration of MSCs for promoting fracture healing in a rat model.METHODS Wistar rats were divided into four groups according to MSC concentrations:Normal saline(C),2.5×10^(6)(L),5.0×10^(6)(M),and 10.0×10^(6)(H)groups.The MSCs were injected directly into the fracture site.The rats were sacrificed at 2 and 6 wk post-fracture.New bone formation[bone volume(BV)and percentage BV(PBV)]was evaluated using micro-computed tomography(CT).Histological analysis was performed to evaluate fracture healing score.The protein expression of factors related to MSC migration[stromal cell-derived factor 1(SDF-1),transforming growth factor-beta 1(TGF-β1)]and angiogenesis[vascular endothelial growth factor(VEGF)]was evaluated using western blot analysis.The expression of cytokines associated with osteogenesis[bone morphogenetic protein-2(BMP-2),TGF-β1 and VEGF]was evaluated using real-time polymerase chain reaction.RESULTS Micro-CT showed that BV and PBV was significantly increased in groups M and H compared to that in group C at 6 wk post-fracture(P=0.040,P=0.009;P=0.004,P=0.001,respectively).Significantly more cartilaginous tissue and immature bone were formed in groups M and H than in group C at 2 and 6 wk post-fracture(P=0.018,P=0.010;P=0.032,P=0.050,respectively).At 2 wk post fracture,SDF-1,TGF-β1 and VEGF expression were significantly higher in groups M and H than in group L(P=0.031,P=0.014;P<0.001,P<0.001;P=0.025,P<0.001,respectively).BMP-2 and VEGF expression were significantly higher in groups M and H than in group C at 6 wk postfracture(P=0.037,P=0.038;P=0.021,P=0.010).Compared to group L,TGF-β1 expression was significantly higher in groups H(P=0.016).There were no significant differences in expression levels of chemokines related to MSC migration,angiogenesis and cytokines associated with osteogenesis between M and H groups at 2 and 6 wk post-fracture.CONCLUSION The administration of at least 5.0×10^(6)MSCs was optimal to promote fracture healing in a rat model of long bone fractures.
文摘Objective:To study the effects of Shang Ke Jie Gu tablet on fracture healing in rabbits.Methods:40 New Zealand rabbits,half male and half female,were randomly divided into two groups:normal saline group(N group)and Shang Ke Jie Gu tablet group(S group).Each group consisted of 20 rabbits.Left radial fracture models in upper and middle sections were made in rabbits and then intra-gastric administration was given.Five rabbits in each group were killed on the 10 th,20^(th),30^(th) and 40^(th) day after surgery,left radius was taken to get an X-ray.The degree of healing was assessed by the evaluation criteria of Shanghai Orthopaedics Institute.Results:The degree of fracture healing in S group was higher in the comparison with that in N group.Conclusions:Shang Ke Jie Gu tablet might affect endochondral ossification during fracture healing of rabbits,and promote porosis and fracture healing.
文摘To investigate the impact of different kinds of nerve injuries of early-stage fracture healing.Methods Three groups of rats were included in the experiment among which group 1 was inflicted with femoral fracture and T10 spinal cord transsection (SCI),group 2 was inflicted with femoral and peripheral nerve resection (PNR),and group 3 with simple femoral fracture as control group.Two weeks after operation the femoral bones were collected for X-ray checking and 2 more weeks later X-ray checking was performed again followed by pathomorphologic exams.Results X-ray result showed no massive calluses in the bones in the 2nd week postoperatively,while in the 4th week,callus appeared with larger size in group 3 than that of group 1 and with smaller size than that of group 2.It was the same with the result of pathomorphologic examining.Cortical bone bridges between fracture point and osteiod were also found in group 2 and there were less normal blood vessels and worse bone remodeling than that of group 3.There were relatively immature calluses with more fibroblast-like cells and disordered bone structure in group 2.Group 3 showed normal healing process and callus structure.Conclusion Early-stage bone fracture healing can be influenced significantly by different kinds of nerve injuries.6 refs,6 figs.
文摘Teriparatide is a recombinant form of the biologicallyactive component of Parathyroid hormone. It has been shown to increase bone mass and prevent fractures in osteoporotic bone. It is licensed by the Food and Drug Administration for the treatment of Osteoporosis. Over the last decade, a growing body of evidence has accumulated suggesting a role for Teriparatide in the management of fractures. Studies in both normal and delayed healing models have shown improvement in callus volume and mineralisation, bone mineral content, rate of successful union and strength at fracture sites. However most of these results have been derived from animal studies. The majority of this research on humans has comprised low level evidence, with few randomised controlled trials, many case reports and case series. Nevertheless, the results from these studies seem to support research from animal models. This has led to a growing number of clinicians using Teriparatide "off license" to treat fractures and non-unions in their patients. This review presents a critical appraisal of the current evidence supporting the use of Teriparatide for fracture healing, delayed unions and non unions and in the setting of osteoporotic fractures, the studies producing this evidence and their transferability to human beings.
基金Indiana University Collaborative Research GrantIndiana Clinical and Translational Sciences Institute,No.NIH UL1TR001108,No.NIH R01 AR069657,No.NIH R01AR060863 and No.NIH R01AG060621
文摘Successful fracture healing requires the simultaneous regeneration of both the bone and vasculature;mesenchymal stem cells (MSCs) are directed to replace the bone tissue, while endothelial progenitor cells (EPCs) form the new vasculature that supplies blood to the fracture site. In the elderly, the healing process is slowed, partly due to decreased regenerative function of these stem and progenitor cells. MSCs from older individuals are impaired with regard to cell number, proliferative capacity, ability to migrate, and osteochondrogenic differentiation potential. The proliferation, migration and function of EPCs are also compromised with advanced age. Although the reasons for cellular dysfunction with age are complex and multidimensional, reduced expression of growth factors, accumulation of oxidative damage from reactive oxygen species, and altered signaling of the Sirtuin-1 pathway are contributing factors to aging at the cellular level of both MSCs and EPCs. Because of these geriatric-specific issues, effective treatment for fracture repair may require new therapeutic techniques to restore cellular function. Some suggested directions for potential treatments include cellular therapies, pharmacological agents, treatments targeting age-related molecular mechanisms, and physical therapeutics. Advanced age is the primary risk factor for a fracture, due to the low bone mass and inferior bone quality associated with aging;a better understanding of the dysfunctional behavior of the aging cell will provide a foundation for new treatments to decrease healing time and reduce the development of complications during the extended recovery from fracture healing in the elderly.
基金This research was partially supported by a grant from NextCure,Inc.and the NIH National Institute on Aging under Award Number P01AG066603.
文摘Osteoporosis(OP)is a common age-related disease characterized by a deterioration of bone mass and structure that predisposes patients to fragility fractures.Pharmaceutical therapies that promote anabolic bone formation in OP patients and OP-induced fracture are needed.We investigated whether a neutralizing antibody against Siglec-15 can simultaneously inhibit bone resorption and stimulate bone formation.We found that the multinucleation of osteoclasts was inhibited in SIGLEC-15 conditional knockout mice and mice undergoing Siglec-15 neutralizing antibody treatment.The secretion of platelet-derived growth factor-BB(PDGF-BB),the number of tartrate-resistant acid phosphatase-positive(TRAP+)mononuclear cells,and bone formation were significantly increased in the SIGLEC-15 conditional knockout mice and antibody-treated mice.The anabolic effect of the Siglec-15 neutralizing antibody on bone formation was blunted in mice with Pdgfb deleted in TRAP-1"cells.These findings showed that the anabolic effect of the Siglec-15 neutralizing antibody was mediated by elevating PDGF-BB production of TRAP4 mononuclear cells.To test the therapeutic potential of the Siglec-15 neutralizing antibody,we injected the antibody in an ovariectomy-induced osteoporotic mouse model,which mimics postmenopausal osteoporosis in women,and in two fracture healing models because fracture is the most serious health consequence of osteoporosis.The Siglec-15 neutralizing antibody effectively reduced bone resorption and stimulated bone formation in estrogen deficiency-induced osteoporosis.Of note,the Siglec-15 neutralizing antibody promoted intramembranous and endochondral ossification at the damaged area of cortical bone in fracture healing mouse models.Thus,the Siglec-15 neutralizing antibody shows significant translational potential as a novel therapy for OP and bone fracture.
基金supported by AR060456 (F.L.), AR047867 (M.J.S.)the Washington University Musculoskeletal Research Center (NIH P30 AR057235)
文摘There remain unmet clinical needs for safe and effective bone anabolic therapies to treat aging-related osteoporosis and to improve fracture healing in cases of nonunion or delayed union. Wnt signaling has emerged as a promising target pathway for developing novel bone anabolic drugs. Although neutralizing antibodies against the Wnt antagonist sclerostin have been tested,Wnt ligands themselves have not been fully explored as a potential therapy. Previous work has demonstrated Wnt7b as an endogenous ligand upregulated during osteoblast differentiation, and that Wnt7b overexpression potently stimulates bone accrual in the mouse. The earlier studies however did not address whether Wnt7b could promote bone formation when specifically applied to aged or fractured bones. Here we have developed a doxycycline-inducible strategy where Wnt7b is temporally induced in the bones of aged mice or during fracture healing. We report that forced expression of Wnt7b for 1 month starting at 15 months of age greatly stimulated trabecular and endosteal bone formation, resulting in a marked increase in bone mass. We further tested the effect of Wnt7b on bone healing in a murine closed femur fracture model. Induced expression of Wnt7b at the onset of fracture did not affect the initial cartilage formation but promoted mineralization of the subsequent bone callus. Thus, targeted delivery of Wnt7b to aged bones or fracture sites may be explored as a potential therapy.
基金supported by Guangdong Science and Technology Projects,grant No.2010b031600288
文摘Objective:To study the effect of aspirin on healing process of osteoporotic fracture(OPF)in rats.Methods:A total of 50 female Wistar rata aged 3 months were randomly divided into observation group and control group,castration method was adopted to establish the osteoporosis(OP)model.After artificial preparing fractures on the midpoint of left femur,fixing gram needle intramedullary.OPF modeling was complete.Aspirin lavage of 33 mg once a day was adoptde in observation group after modeling,same amount of normal saline was used in the control as placebo.From eash group,selected 5 rats at the 2nd.4th,8th and 12th week after modeling to measure the bone mineral density(BMD)and histogical examination of the fracture callus,radiology observation was conducted at the 8th and 12th week.Left femur biomechanical measurement was taken at the 12th week.Results:BMD values of observation group at each time point were significantly higher than that of the control group after modeling(P<0.05);Histological observation showed that at the 8th week,the endochondral ossification process of observation group was faster than that of observation group,with fuzzy fracture line in observation group and clear fracture line in observtion group;at the 12th week,fracture line disappeared in observation group,fracture line of the control group was fuzzy at the same time;three-point bending load of the left femur in observation group rats was significantly higher than that of control group after12 weeka(P<0.05).Conclusions:Asporin can accelerate the healing of new callus in OPF rats,increase bone density and biomechanics strength,and promote fracture of osteporotic rats.
文摘BACKGROUND Non-steroidal anti-inflammatory drugs(NSAIDs)are among the most commonly prescribed medications in the United States.Although they are safe and effective means of analgesia for children with broken bones,there is considerable variation in their clinical use due to persistent concerns about their potentially adverse effect on fracture healing.AIM To assess whether NSAID exposure is a risk factor for fracture nonunion in children.METHODS We systematically reviewed the literature reporting the effect of NSAIDs on bone healing.We included all clinical studies that reported on adverse bone healing complications in children with respect to NSAID exposure.The outcomes of interest were delayed union or nonunion.Study quality was assessed using the Newcastle-Ottawa scale for non-randomized studies.A final table was constructed summarizing the available evidence.RESULTS A total of 120 articles were identified and screened,of which 6 articles were included for final review.Nonunion in children is extremely rare;among the studies included,there were 2011 nonunions among 238822 fractures(0.84%).None of the included studies documented an increased risk of nonunion or delayed bone healing in those children who are treated with NSAIDs in the immediate post-injury or peri-operative time period.Additionally,children are likely to take these medications for only a few days after injury or surgery,further decreasing their risk of adverse side-effects.CONCLUSION This systematic review suggests that NSAIDS can be safely prescribed to pediatric orthopaedic patients absent other contraindications without concern for increased risk of fracture non-union or delayed bone healing.Additional prospective studies are needed focusing on higher risk fractures and elective orthopaedic procedures such as osteotomies and spinal fusion.
基金supported by grants from the“PAKT für Forschung und Innovation2010(Leibniz Age Net:signaling pathways in age-related diseases)”German Research Foundation(DFG)Tu220/14-1,DFG(No.Ci 216/2-1)+1 种基金DFG in the framework of Collaborative Research Center CRC1149“Danger Response,Disturbance Factors and Regenerative Potential after Trauma”(No.251293561—CRC 1149,INST 40/492-1 and INST 40/492-2)Open Access funding enabled and organized by Projekt DEAL。
文摘Identification of regulators of osteoblastogenesis that can be pharmacologically targeted is a major goal in combating osteoporosis,a common disease of the elderly population. Here, unbiased kinome RNAi screening in primary murine osteoblasts identified cyclin-dependent kinase 5(Cdk5) as a suppressor of osteoblast differentiation in both murine and human preosteoblastic cells. Cdk5 knockdown by si RNA, genetic deletion using the Cre-lox P system, or inhibition with the small molecule roscovitine enhanced osteoblastogenesis in vitro. Roscovitine treatment significantly enhanced bone mass by increasing osteoblastogenesis and improved fracture healing in mice. Mechanistically, downregulation of Cdk5 expression increased Erk phosphorylation, resulting in enhanced osteoblast-specific gene expression. Notably, simultaneous Cdk5 and Erk depletion abrogated the osteoblastogenesis conferred by Cdk5 depletion alone, suggesting that Cdk5 regulates osteoblast differentiation through MAPK pathway modulation. We conclude that Cdk5 is a potential therapeutic target to treat osteoporosis and improve fracture healing.
文摘Objective:To compare the clinical therapeutic effect of bridge combined internal fixation system and locking compression plate internal fixation in the treatment of displaced midshaft clavicle fractures by emphatically observing fracture healing and shoulder joint function.Methods:Totally 44 elderly patients with Robinson type 2B displaced midshaft clavicle fractures were included from the Department of Orthopaedics,Shenyang Fourth People's Hospital during February 2016 and December 2018,including 23 males and 21 females,mean age(69.8±10.2)years old.The patients were divided into a bridge combined internal fixation system group(bridge group,n=22)and a locking compression plate internal fixation group(plate group,n=22)according to the internal fixation methods.The operation time,intraoperative blood loss,fracture healing time,and postoperative complications were recorded.At 12 months after surgery,the shoulder joint Constant-Murley score and DASH score were used to assess the recovery of joint function.The serum levels of bone turnover biochemical markers procollagen I N-terminal peptide(P1NP),cross-linked Carboxy-terminal telopeptide of typeⅠcollagen(CTX-I),and osteoblast specific factor(OSF)were measured before and 3 months after surgery.Results:The operation time,intraoperative blood loss and fracture healing time of the bridge group were significantly shorter than those of the plate group(P<0.05).Constant scores and DASH scores in the bridge group were significantly better than those of the plate group at 12 months after surgery(P<0.05).Serum levels of CTX-I was significantly decreased,while the P1NP and OSF were significantly increased compared with before surgery in the both groups(P<0.05),and the changes were more obvious in the bridge group(P<0.05).The incidence of complications was similar between the two groups(P<0.05).Conclusion:Compared with the locking plate system,the bridge combined internal fixation system can effectively improve the operation efficiency,have more benefits on fracture healing,better promote the recovery of patients'function,and reduce the failure rate of internal fixation,thus providing a better choice to treat displaced midshaft clavicle fractures by intraoperative internal fixation.
文摘To observe the safety and effectiveness of a topical herbal agent used to promote fracture healing, a herbal patch containing extracts of three herbs, viz., Flos Carthami, Radix Dipsaci, Rhizoma Rhei and Borneolum Syntheticum (an enhancer) was applied on ten subjects with un-displaced fifth metatarsal fractures. Pain scores, foot and ankle function questionnaires and regional swelling were carefully assessed and recorded. Peripheral blood was taken to measure the inflammation cytokines. Assessment checks were performed biweekly to enforce effective patch application and compliance. The results showed that pain improved after two weeks and fracture sites swelling had 20% reduction in thickness when measured with an ultrasonic tool. Foot and ankle functional scores markedly improved after six weeks. Radiological examinations revealed early perfect fracture unions. The topical herbal patch was effective in promoting fracture healing. It was well tolerated by the fracture patients. Larger randomized controlled trials would be indicated.
基金This project was supported by the National Natural Science Foundation of China !(No. 969202011 ) by Hubei Province Natural S
文摘Summary: In order to investigate the effect of a new institute-designed absorbable hydroxyapatite microparticles/poly-DL-lactide (HA/PDLLA) fracture fixation devices on experimental fracture healing, 25 rabbits with a transverse transcondylar osteotomy of the distal femur were fixed in- tramedullary by a HA/PDLLA rod (4. 5 mm in diameter, 30-40 mm in length). The follow-up time lasted 1, 2, 4, 6 and 12 week(s). Roentgenographic, histological and ultrastructural analyses were conducted. The results showed that all osteotomies united within 6 weeks without delay. No accumulation of inflammatory cells was seen. Ultrastructural studies showed that polymorphonuclear neutrophils and macrophages were observed mainly at the 1st week, but only few were noted at the 2nd week. The inflammatory and debridement stages were not prolonged. Large amount of active fibroblasts and some chondroblasts were observed at the 2nd week, suggesting a fibrous callus stage. The main cellularity at 4th week was osteoblasts and osteocytes. Part of osteocytes had already entered the static stage at the 6th week. Our experiment showed that the HA/PDLLA had good biocompatibility, sufficient mechanical strength and caused no delay to the fracture healing.
文摘The trabecular bone fracture healing differs from diaphyseal fracture healing, in which trabecular bone heals based on intramembraneous ossification. The process includes a small callus formation, then woven bone forms, it follows by remodeling process to form regular trabecular bone. The objective of this study was to present an energy based model to simulate bone formation and remodeling during trabecular bone fracture healing. This modeling mainly focused on the mechanical factors. The model distinguishes three basic type of tissue: bone, cartilage and soft tissue. In order to determine tissue differentiation a fuzzy controller was proposed. An algorithm was developed to link the fuzzy logic controller to a finite element model (FEM) of trabecular bone. In general, finite element analysis provides input for fuzzy controller. Based on the input data, the fuzzy system selects the type of tissue to build. Strain energy density was used as the mechanical stimulus and a new parameter was incorporated in to the healing process as the remodeling index.
文摘Following fracture of left tibia in 14 Wistar rats the mitosis and proliferation of various cellular components in callus tissues were studied with ~3H-Thymidine labelling and radioautographic technique. There was accumulation of silver grains over the nuclei of mesenchymal cells ,endothelial cells of capillaries, fibroblasts and chondrocytes as a result of mitosis and incorporation of the labelling isotopes. Although the osteoblasts and osteocytes could not divide they derived from the mesenchymal cells and osteogenic cells, thus showing silver grains as well. Besides, fat cells and muscle cells likewise revealed silver grains signifying that in fracture healing a number of connective tissue cells underwent mitosis and proliferation.
文摘Background: In this experimental study, we aimed to determine the possible changes in fracture healing due to denervation and/or nerve ending interpositioning. Methods: 50 Wistar Albino type male rats were divided into three study groups. A standard transverse diaphysial fracture in the femurs of the same side of all subjects under anesthesia was created and the fracture were fixed intramedullarily. While preserving the structural integrity of the sciatic nerve in the first group, neurectomy to the nerve in the second group was performed. In the third group, following the sciatic nerve cut, the proximal end of the nerve were interposed the fracture line. After a 28-day observational period, the callus formation in the subjects was examined radiologically, biomechanically and histopathologically. Results: Among all groups, the third group subjects showed significant increase in radiological area measurements when they are compared to the second group rats. There was no significant difference in biomechanical measurements of fractured femurs of the three groups. In histopathological evaluations, it was observed that denervation had increased the thickness of the cartilage and the number of the chondrocytes and osteoclasts significantly but decreased the number of fibroblasts compared to the control group. In addition to the denervation nerve ending interpositioning increased the bone thickness and the number of the osteoblasts but decreased the number of the osteoclasts significantly. Conclusions: While radiological observations exhibit that nerve ending interpositioning has resulted more hypertrophic callus formation, histopathological evaluations led us to that denervation created partial (immature) callus formation and nerve ending interpositioning demonstrated larger but immature callus formation.
