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Abstract Background The inflammatory microenvironment plays an essential role in bone healing after fracture. The signaling lymphocytic activation molecule family (SLAMF) members deeply participate in inflammatory response and make a vast difference. Methods We identified SLAMF8 in GEO datasets (GSE129165 and GSE176086) and co-expression analyses were performed to define the relationships between SLAMF8 and osteogenesis relative genes (RUNX2 and COL1A1). In vitro, we established SLAMF8 knockdown and overexpression mouse bone marrow mesenchymal stem cells (mBMSCs) lines. qPCR, Western blot, ALP staining, ARS staining, Oil Red O staining and Immunofluorescence analyses were performed to investigate the effect of SLAMF8 in mBMSCs osteogenesis and adipogenesis. In vivo, mice femoral fracture model was performed to explore the function of SLAMF8. Results SLAMF8 knockdown significantly suppressed the expression of osteogenesis relative genes (RUNX2, SP7 and COL1A1), ALP activity and mineral deposition, but increased the expression of adipogenesis relative genes (PPARγ and C/EBPα). Additionally, SLAMF8 overexpression had the opposite effects. The role SLAMF8 played in mBMSCs osteogenic and adipogenic differentiation were through S100A6 and Wnt/β-Catenin signaling pathway. Moreover, SLAMF8 overexpression mBMSCs promoted the healing of femoral fracture. Conclusions SLAMF8 promotes osteogenesis and inhibits adipogenesis of mBMSCs via S100A6 and Wnt/β-Catenin signaling pathway. SLAMF8 overexpression mBMSCs effectively accelerate the healing of femoral fracture in mice.

Abstract Background Despite centuries of traditional use of silymarin for hepatoprotection, current randomized controlled trial (RCT) studies on the effectiveness of silymarin in managing metabolic dysfunction-associated steatotic liver disease (MASLD) are limited and inconclusive, particularly when it is administered alone. The low bioavailability of silymarin highlights the possible influence of gut microbiota on the effectiveness of silymarin; however, no human studies have investigated this aspect. Objective To determine the potential efficacy of silymarin in improving MASLD indicators and to investigate the underlying mechanisms related to gut microbiota. Method In this 24-week randomized, double-blind, placebo-controlled trial, 83 patients with MASLD were randomized to either placebo (n = 41) or silymarin (103.2 mg/d, n = 42). At 0, 12, and 24 weeks, liver stiffness and hepatic steatosis were assessed using FibroScan, and blood samples were gathered for biochemical detection, while faecal samples were collected at 0 and 24 weeks for 16S rRNA sequencing. Results Silymarin supplementation significantly reduced liver stiffness (LSM, -0.21 ± 0.17 vs. 0.41 ± 0.17, P = 0.015) and serum levels of γ-glutamyl transpeptidase (GGT, -8.21 ± 3.01 vs. 1.23 ± 3.16, P = 0.042) and ApoB (-0.02 ± 0.03 vs. 0.07 ± 0.03, P = 0.023) but had no significant effect on the controlled attenuation parameter (CAP), other biochemical indicators (aminotransferases, total bilirubin, glucose and lipid parameters, hsCRP, SOD, and UA), physical measurements (DBP, SBP, BMI, WHR, BF%, and BMR), or APRI and FIB-4 indices. Gut microbiota analysis revealed increased species diversity and enrichment of Oscillospiraceae in the silymarin group. Conclusion These findings suggest that silymarin supplementation could improve liver stiffness in MASLD patients, possibly by modulating the gut microbiota. Trial registration The trial was registered at the Chinese Clinical Trial Registry (ChiCTR2200059043).

Abstract Background The treatment of Dubberley type B capitellar fractures, which are frequently complicated, is widely debated. This study aimed to investigate the prognostic factors and clinical outcomes of Dubberley type B capitellar fractures treated with Herbert screws combined with posterior buttress plates. Methods Seven men and nine women (aged 30–68 years) with Dubberley type B capitellar fractures were operated on with Herbert screws combined with posterior buttress plates. The patients were classified into Dubberley types IB (seven), IIB (four), and IIIB (five). Complications and bone union were observed, and functional outcomes were evaluated by the Mayo Elbow Performance Index (MEPI). Results All patients were followed up for a mean period of 23.5 months (12–30 months). All fractures healed in 8–14 weeks (mean, 10.5 weeks). No cases of non-union, elbow instability, or avascular necrosis occurred. Degenerative arthritis occurred in 7 (44%) and heterotopic ossification in 11 (69%) patients. The median MEPI score was 92.5 (interquartile range, 85–100) points, with 11 reporting excellent, 3 good, and 2 fair outcomes. The MEPI scores of type IIIB fractures were significantly lower than those of types IB and IIB fractures, while the MEPI scores of type IB and IIB fractures did not differ significantly. Conclusions Dubberley type IIIB capitellar fractures with multiple articular fragments have a poorer prognosis than type IB and IIB fractures. However, Herbert screw fixation combined with posterior metacarpal locking plates is feasible, providing satisfactory recovery of elbow joint function.

Abstract Background The available therapeutic options for large bone defects remain extremely limited, requiring new strategies to accelerate bone healing. Genetically modified bone mesenchymal stem cells (BMSCs) with enhanced osteogenic capacity are recognised as one of the most promising treatments for bone defects. Methods We performed differential expression analysis of miRNAs between human BMSCs (hBMSCs) and human dental pulp stem cells (hDPSCs) to identify osteogenic differentiation-related microRNAs (miRNAs). Furthermore, we identified shared osteogenic differentiation-related miRNAs and constructed an miRNA-transcription network. The Forkhead box protein A1 (FOXA1) knockdown strategy with a lentiviral vector was used to explore the role of FOXA1 in the osteogenic differentiation of MSCs. Cell Counting Kit-8 was used to determine the effect of the knockdown of FOXA1 on hBMSC proliferation; real-time quantitative reverse transcription PCR (qRT-PCR) and western blotting were used to investigate target genes and proteins; and alkaline phosphatase (ALP) staining and Alizarin Red staining (ARS) were used to assess ALP activity and mineral deposition, respectively. Finally, a mouse model of femoral defects was established in vivo, and histological evaluation and radiographic analysis were performed to verify the therapeutic effects of FOXA1 knockdown on bone healing. Results We identified 22 shared and differentially expressed miRNAs between hDPSC and hBMSC, 19 of which were downregulated in osteogenically induced samples. The miRNA-transcription factor interaction network showed that FOXA1 is the most significant and novel osteogenic differentiation biomarker among more than 300 transcription factors that is directly targeted by 12 miRNAs. FOXA1 knockdown significantly promoted hBMSC osteo-specific genes and increased mineral deposits in vitro. In addition, p-ERK1/2 levels were upregulated by FOXA1 silencing. Moreover, the increased osteogenic differentiation of FOXA1 knockdown hBMSCs was partially rescued by the addition of ERK1/2 signalling inhibitors. In a mouse model of femoral defects, a sheet of FOXA1-silencing BMSCs improved bone healing, as detected by microcomputed tomography and histological evaluation. Conclusion These findings collectively demonstrate that FOXA1 silencing promotes the osteogenic differentiation of BMSCs via the ERK1/2 signalling pathway, and silencing FOXA1 in vivo effectively promotes bone healing, suggesting that FOXA1 may be a novel target for bone healing.

Abstract Background Aucubin (AU), an iridoid glucoside isolated from many traditional herbal medicines, has anti-osteoporosis and anti-apoptosis bioactivities. However, the effect of AU on the treatment of bone-fracture remains unknown. In the present study, the aims were to investigate the roles and mechanisms of AU not only on osteoblastogenesis of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) and anti-oxidative stress injury in vitro, but also on bone-fracture regeneration by a rat tibial fracture model in vivo. Methods CCK-8 assay was used to assess the effect of AU on the viability and proliferation of hBM-MSCs. The expression of specific genes and proteins on osteogenesis, apoptosis and signaling pathways was measured by qRT-PCR, western blotting and immunofluorescence analysis. ALP staining and quantitative analysis were performed to evaluate ALP activity. ARS and quantitative analysis were performed to evaluate calcium deposition. DCFH-DA staining was used to assess the level of reactive oxygen species (ROS). A rat tibial fracture model was established to validate the therapeutic effect of AU in vivo. Micro-CT with quantitative analysis and histological evaluation were used to assess the therapeutic effect of AU locally injection at the fracture site. Results Our results revealed that AU did not affect the viability and proliferation of hBM-MSCs. Compared with control group, western blotting, PCR, ALP activity and calcium deposition proved that AU-treated groups promoted osteogenesis of hBM-MSCs. The ratio of phospho-Smad1/5/9 to total Smad also significantly increased after treatment of AU. AU-induced expression of BMP2 signaling target genes BMP2 and p-Smad1/5/9 as well as of osteogenic markers COL1A1 and RUNX2 was downregulated after treating with noggin and LDN193189. Furthermore, AU promoted the translocation of Nrf2 from cytoplasm to nucleus and the expression level of HO1 and NQO1 after oxidative damage. In a rat tibial fracture model, local injection of AU promoted bone regeneration. Conclusions Our study demonstrates the dual effects of AU in not only promoting bone-fracture healing by regulating osteogenesis of hBM-MSCs partly via canonical BMP2/Smads signaling pathway but also suppressing oxidative stress damage partly via Nrf2/HO1 signaling pathway.

Abstract Background Globally, bone fractures are the most common musculoskeletal trauma, and approximately 8–10% of cases that fall into the categories of delayed or non-union healing. To date, there are no efficient pharmacological agents to accelerate the healing of bone fractures. Thus, it is necessary to find new strategies that accelerate bone healing and reduce the incidence of non-union or delayed fracture healing. Previous studies have revealed that the plasminogen activation system has been demonstrated to play an important role in bone metabolism. However, the function of SERPINB2 in the osteogenesis of hBMSCs remains unclear. Therefore, in this study, we investigated the effects and mechanism of SERPINB2 on osteogenic differentiation. Methods We investigated the osteogenesis effects of hBMSCs by both exogenous SerpinB2 protein and SERPINB2 gene silencing in vitro. Cell proliferation assay was used to assess the effect of exogenous SerpinB2 or SERPINB2 silencing on proliferation of hBMSCs. qPCR and Western blotting analysis detected the expression of target genes and proteins respectively. ALP staining was used to evaluated ALP activity and Alizarin Red staining (ARS) was used to evaluate mineral deposition. In vivo, a murie tibial fracture model was established, histological evaluation and radiographic analysis was used to confirm the therapeutic effects of SERPINB2 silencing in fracture healing. Statistical significance between two groups was determined by Student’s t test, one-way ANOVA or Bonferroni’s post-hoc test according to the distribution of the tested population. Results The addition of exogenous SerpinB2 protein inhibted osteoblast differentiation of hBMSCs in vitro, while SERPINB2 gene silencing significant promote osteoblast differentiation of hBMSCs in vitro. And silenced SERPINB2 gene also increased mineral deposits. Moreover, β-catenin levels were up-regulated by SERPINB2 gene depletion. And the enhancement of osteogenic differentiation induced by SERPINB2 silencing was almost inhibited by specific Wnt/β-catenin signaling pathway inhibitor. In a murine tibial fracture model, local injection of SERPINB2 siRNA improved bone fracture healing. Conclusions Taken together, these findings indicate that SERPINB2 silencing promoted osteogenic differentiation of BMSCs via the Wnt/β-catenin signaling pathway, and silenced SERPINB2 in vivo effectively promotes fracture healing, suggesting that SERPINB2 may be a novel target for bone fracture healing.

Abstract Background Inflammatory microenvironment is significant to the differentiation and function of mesenchymal stem cells (MSCs). It evidentially influences the osteoblastogenesis of MSCs. IL-34, a newly discovered cytokine, playing a key role in metabolism. However, the research on its functional role in the osteogenesis of MSCs was rarely reported. Here, we described the regulatory effects of low-dose IL-34 on both osteoblastogenesis and osteoclastogenesis. Methods We performed the osteogenic effects of hBMSCs by exogenous and overexpressed IL-34 in vitro, so were the osteoclastogenesis effects of mBMMs by extracellular IL-34. CCK-8 was used to assess the effect of IL-34 on the viability of hBMSCs and mBMMs. ALP, ARS, and TRAP staining was used to evaluate ALP activity, mineral deposition, and osteoclastogenesis, respectively. qRT-PCR and Western blotting analysis were performed to detect the expression of target genes and proteins. ELISA was used to evaluate the concentrations of IL-34. In vivo, a rat tibial osteotomy model and an OVX model were established. Radiographic analysis and histological evaluation were performed to confirm the therapeutic effects of IL-34 in fracture healing and osteoporosis. Statistical differences were evaluated by two-tailed Student’s t test, one-way ANOVA with Bonferroni’s post hoc test, and two-way ANOVA with Bonferroni multiple comparisons post hoc test in the comparison of 2 groups, more than 2 groups, and different time points of treated groups, respectively. Results Promoted osteoblastogenesis of hBMSCs was observed after treated by exogenous or overexpressed IL-34 in vitro, confirmed by increased mineral deposits and ALP activity. Furthermore, exogenous or overexpressed IL-34 enhanced the expression of p-AKT and p-ERK. The specific AKT and ERK signaling pathway inhibitors suppressed the enhancement of osteoblastogenesis induced by IL-34. In a rat tibial osteotomy model, imaging and histological analyses testified the local injection of exogenous IL-34 improved bone healing. However, the additional IL-34 has no influence on both osteoclastogenesis of mBMMs in vitro and osteoporosis of OVX model of rat in vivo. Conclusions Collectively, our study demonstrate that low-dose IL-34 regulates osteogenesis of hBMSCs partly via the PIK/AKT and ERK signaling pathway and enhances fracture healing, with neither promoting nor preventing osteoclastogenesis in vitro and osteoporosis in vivo.

Abstract Background No standardized protocol has been suggested in the treatment of postoperative osteomyelitis following fracture fixation. Our team evaluates the clinical efficacy of the modified algorithm for managing postoperative osteomyelitis following fracture fixation with Cierny–Mader type. Methods Ninety-five wounds were reviewed from March 2009 to February 2016 in our hospital. Sixty-one wounds were treated by the modified algorithm as follows: stable hardware + bone not healed Cierny–Mader 1 type = remove hardware, temporary stabilize; stable hardware + bone not healed Cierny–Mader 2 type = retain hardware ; stable hardware + bone not healed Cierny–Mader for type 3 and type 4 = remove hardware, temporary stabilize/Ilizarov technique; unstable hardware + bone not healed = remove hardware, temporary stabilize/Ilizarov technique; and stable hardware + bone healed = remove hardware. Thirty-four wounds were treated by the conventional algorithm. Autodermoplasty, flap transfer, myocutaneous flap, and other methods including antibiotic irrigation and drug delivery system were used in wound repair. Results The patients treated with modified algorithm had a significantly reduced recurrence (P < 0.01) and increased results of negative bacterial cultures (P < 0.01); however, a decrease in the number of retained hardware cases was observed (P < 0.05). For those treated with tissue reconstruction, there was no significance (P > 0.05) compared with the conventional group. Conclusions The modified algorithm for the postoperative osteomyelitis following fracture fixation according to the stability of the hardware and Cierny–Mader type represents a good clinical efficacy in the management of postoperative osteomyelitis. This procedure is simple and shows promising results; more clinical evidence is needed to confirm the existing findings and optimize the treatment of postoperative osteomyelitis following fracture fixation.

Abstract Background Management of fracture healing with a large bone defect remains a tricky subject in orthopedic trauma. Enhancing osteogenesis of human bone marrow-derived mesenchymal stem cells (hBMSCs) is one of the useful therapeutic strategies for fracture healing. Previous studies have revealed that Apelin may play an important role in bone metabolism. However, its function in the osteogenesis of hBMSCs remains unclear. Therefore, in this study, we investigated the effects and mechanism of Apelin on osteogenic differentiation. Methods We investigated the osteogenesis effects of hBMSCs by both exogenous Apelin protein and overexpression Apelin in vitro. Cell proliferation assay was used to assess the effect of Apelin on the proliferation of hBMSCs. ALP staining and Alizarin Red staining were used to evaluate ALP activity and mineral deposition respectively. qPCR and Western blotting analysis were used to detect the expression of target genes and proteins. In vivo, a rat tibial osteotomy model was established; radiographic analysis and histological evaluation were used to confirm the therapeutic effects of Apelin in fracture healing. Statistical significance was determined by two-tailed Student’s t test when 2 groups were compared. When more than 2 groups were compared, one-way ANOVA followed by Bonferroni’s post-hoc test was used. And two-way ANOVA, followed by Bonferroni multiple comparisons post-hoc test, was performed when the treatment groups at different time points were compared. Results The addition of exogenous Apelin protein or overexpression of Apelin promoted osteoblast differentiation of hBMSCs in vitro. Increased mineral deposits were observed after treatment with extracellular Apelin protein or after the upregulation of Apelin. Moreover, β-catenin levels were upregulated by Apelin. The enhancement of osteogenic differentiation induced by Apelin was attenuated by specific Wnt/β-catenin signaling pathway inhibitors. In a rat tibial osteotomy model, local injection of exogenous Apelin protein improved bone healing, as demonstrated by imaging and histological analyses. Conclusions Taken together, these findings indicate that Apelin regulates osteogenic differentiation of hMSCs partly via the Wnt/β-catenin signaling pathway and effectively promotes fracture healing.

Abstract Background Our hospital has recently used the extended anterolateral approach in posterolateral tibial plateau fracture. We compared the clinical effects of this method in Schatzker type II or type V/VI fractures with posterolateral tibial plateau fracture based on our patients. Methods The patients from January 2013 to December 2015 were summarized, and some of them were assisted with arthroscopy. According to Schatzker classification, patients with Schatzker type II fracture were divided into group A; patients with Schatzker type V/VI fracture were divided into group B. The fracture characteristics, operation statistics, and postoperative functional evaluation of each group were compared. Results A total of 46 patients were included in the study and were followed up for 23–45 months. There were 24 cases in group A and 22 cases in group B. The operation time and the amount of bleeding were significantly less in group A (P 0.05). All patients experienced no significant influence on daily life. The knee Rasmussen score was 26.8 in group A and 23.5 in group B (P > 0.05), and the knee range motion was 115.5° in group A and 106.6° in group B (P > 0.05). The excellent and good rate of reduction was 91.7% in group A and 81.8% in group B (P > 0.05), but the excellent rate of reduction was 83.3% in group A and 27.3% in group B (P 0.05). One patient in group B suffered postoperative wound infection. Conclusions The extended anterolateral approach could obtain similar satisfactory clinical results in simple/complex tibial plateau fracture with posterolateral tibial plateau fracture. It seemed that easier operation, better posterolateral fracture reduction, and fixation occurred in relative simple fracture from our cases. Trial registration It was a retrospective study. This study was consistent with the ethical standards of the Second Affiliated Hospital of Zhejiang University Medical College and was approved by the hospital ethics committee and the trial registration number of our hospital was 20170053.

Abstract Background The use of bone graft for the radial head fractures has been previously described and occasionally used by other authors.This is the first paper, to my knowledge, dealing with the relevant issue about the importance that the use of an autologous bone graft can have on the radial head fractures. Methods From July 2010 to July 2014, 20 consecutive patients who underwent open reduction and internal fixation for a closed Mason type II radial head fracture were retrospectively reviewed. Patients with Mason type I, III, simple type II, and comminuted type II fractures treated without bone grafting were excluded. A clinical examination and radiographic evaluation were performed. The overall functional result was evaluated using the Mayo Elbow Performance Score (MEPS). The Broberg and Morrey classification was used to evaluate traumatic arthritis. Results The average follow-up duration was 31 months (range, 24–50 months). Bone union of the radial head fracture was achieved in all patients at an average of 13.5 weeks (range, 12–17 weeks). Postoperative radiographs showed no cases of postsurgical ligamentous instability, necrosis of the radial head, or internal fixation failure. The mean range of motion of the affected elbow was 128° ± 8.4° in flexion, 14.5° ± 11.1° in extension, 68.7° ± 14.1° in pronation, and 65.2° ± 18.2° in supination. The mean MEPS was 92 ± 7.9 points (range, 80–100); the outcome was excellent (90–100 points) in 13 patients and good (75–89 points) in 7 patients. The MEPS tended to be higher in patients with an isolated fracture (p = 0.016). Based on the Broberg and Morrey classification for radiographic assessment of post-traumatic arthritis, 15 elbows had no evidence of degenerative changes (grade 0), and 5 elbows had grade 1 changes. Conclusion Although radial head fractures may not be amenable to internal fixation, our findings suggest that open reduction and internal fixation with an autogenous bone graft from the lateral epicondyle of the humerus provides satisfactory elbow function in patients with comminuted Mason type II radial head fractures.

Abstract Background Tourniquet is widely used by orthopedic surgeons in total knee arthroplasty (TKA). However, there are still controversies on the optimal timing of tourniquet application. The aim of this meta-analysis was to compare the effect and safety of tourniquet application only during cementation with long-duration tourniquet application in TKA. Methods An electronic literature search of PubMed, the Cochrane library, Embase, and Web of Science was conducted in July 2017. All randomized controlled trials (RCTs) comparing tourniquet application only during cementation with long-duration tourniquet application in TKA were included. RevMan 5.3 software was selected to perform the meta-analysis. Results Seven studies involving 440 TKAs were included for meta-analysis. The results suggested that although significant less intraoperative and total blood loss were observed with long-duration tourniquet application, tourniquet application only during cementation would not increase the number of transfusion and operation time. Tourniquet application only during cementation results in less knee pain on post-operative day 1 (POD 1), less time needed to achieve straight-leg raise, and less minor complications following TKA. Conclusions Tourniquet application only during cementation might reduce the rate of minor complications and have faster functional recovery during the early rehabilitation period following TKA, but it could not limit intraoperative and total blood loss. No definitive conclusions can be drawn based on the current evidences. Further, large well-designed RCTs with extensive follow-up are still needed to validate this research.