Panda rope bridge technique versus open repair of acute Achilles tendon rupture: A comparative clinical study.

PURPOSE: The treatment options of acute Achilles tendon rupture (AATR) remain controversial. This article aims to compare the efficacy of a new surgical procedure, the panda rope bridge technique (PRBT) with open surgery of AATR. METHODS: Ninety-eight patients with AATR were recruited, 53 underwent the PBRT, and 45 underwent open surgery. The operation time, postoperative American Orthopaedic Foot and Ankle Score, Achilles Tendon Rupture Score, complications and time to return to work and restore exercise were documented. RESULTS: The average operation time, intraoperative blood loss and complication rate were 35.1 min, 18.2 ml and 3.8%, respectively, in the PRBT group, which were significantly lower than those of the open surgery group (P<0.001). The post-operative American Orthopaedic Foot and Ankle Score of 99.6 and the Achilles Tendon Rupture Score of 97.5 in the PRBT group were significantly higher than that of the open surgery group (P<0.001). The time to return to work and return to exercise were shorter in the PRBT group (P<0.001). CONCLUSION: Compared to open surgery, PRBT is a better approach to the management of AATR. PRBT offers accelerated recovery, lower occurrence of post-operative complications and improved recovery of ankle joint function.

Correction: Adenovirus-Mediated Efficient Gene Transfer into Cultured Three-Dimensional Organoids.

[This corrects the article DOI: 10.1371/journal.pone.0093608.].

Characteristics and prognosis of telangiectatic osteosarcoma: a population-based study using the Surveillance, Epidemiology and End Results (SEER) database.

BACKGROUND: Telangiectatic osteosarcoma (TOS) is a rare type of osteosarcoma for which limited clinical data is available. Furthermore, the clinical characteristics and prognosis of TOS remain unclear. METHODS: A large population-based cohort analysis was conducted using the Surveillance, Epidemiology and End Results (SEER) registry. The data of TOS and conventional osteosarcoma (COS) patients from 2000 to 2017 were collected. The categorical variables were assessed by Chi-squared tests. Kaplan-Meier curves and log-rank (Mantel-Cox) tests were used to examine the survival outcomes between the groups. Cox proportional hazard models were used for univariate and multivariate analyses of TOS patient survival-related variables. RESULTS: A total of 141 TOS patients and 2961 COS patients were included in this analysis, and the mean age at diagnosis was 23.5 and 29.4 years, respectively. Compared to COS patients, TOS patients were more likely to be under 20 years old (61.7% vs. 51.7%, P=0.022), and without a second peak of incidence after 60 years of age. The median overall survival (mOS) of TOS patients was not reached compared to a median survival of 84 months for COS patients (hazard ratio 0.75, 95% confidence interval 0.59 to 0.95, P=0.0175). After adjusting these data for age at diagnosis, stage, and surgery at the primary site, no significant differences in mOS were observed between the two groups. In univariate analyses, being under 20 years of age, having localized or regional stage disease, and having undergone surgery were associated with a decreased risk of death. Subsequent multivariate analysis indicated that age at diagnosis, stage, and surgery at the primary site were all independent predictors of prognosis in TOS patients. CONCLUSIONS: Patients with TOS were younger than patients with COS and did not show a second peak after 60 years of age. Age, summary stage at diagnosis, and surgery at the primary site were independent predictors of survival for TOS patients.

Targeting local lymphatics to ameliorate heterotopic ossification via FGFR3-BMPR1a pathway.

Acquired heterotopic ossification (HO) is the extraskeletal bone formation after trauma. Various mesenchymal progenitors are reported to participate in ectopic bone formation. Here we induce acquired HO in mice by Achilles tenotomy and observe that conditional knockout (cKO) of fibroblast growth factor receptor 3 (FGFR3) in Col2+ cells promote acquired HO development. Lineage tracing studies reveal that Col2+ cells adopt fate of lymphatic endothelial cells (LECs) instead of chondrocytes or osteoblasts during HO development. FGFR3 cKO in Prox1+ LECs causes even more aggravated HO formation. We further demonstrate that FGFR3 deficiency in LECs leads to decreased local lymphatic formation in a BMPR1a-pSmad1/5-dependent manner, which exacerbates inflammatory levels in the repaired tendon. Local administration of FGF9 in Matrigel inhibits heterotopic bone formation, which is dependent on FGFR3 expression in LECs. Here we uncover Col2+ lineage cells as an origin of lymphatic endothelium, which regulates local inflammatory microenvironment after trauma and thus influences HO development via FGFR3-BMPR1a pathway. Activation of FGFR3 in LECs may be a therapeutic strategy to inhibit acquired HO formation via increasing local lymphangiogenesis.

Biomechanical Comparison of Panda Rope Bridge Technique and Other Minimally Invasive Achilles Tendon Repair Techniques In Vitro.

BACKGROUND: Although nonoperative management of acute Achilles tendon rupture (ATR) is a reasonable option, surgical repair has attracted attention for young and active patients. More reliable Achilles tendon repair techniques are needed to enhance recovery after ATR in this population. PURPOSE/HYPOTHESIS: To biomechanically analyze the panda rope bridge technique (PRBT) and compare it with other minimally invasive repair techniques over a simulated, progressive rehabilitation program. It was hypothesized that PRBT would result in better biomechanical properties and enhanced recovery after ATR. STUDY DESIGN: Controlled laboratory study. METHODS: An Achilles tendon rupture was created 4 cm from the distal tendon insertion site in 40 bovine lower extremities, and specimens were then randomly allocated to 5 Achilles tendon repair techniques: (1) Achillon, (2) modified Achillon, (3) Percutaneous Achilles Repair System (PARS), (4) modified PARS, and (5) PRBT. Each group was subjected to a cyclic loading protocol that was representative of progressive postoperative rehabilitation for ATR (250 cycles at 1 Hz for each loading stage: 20-100 N, 20-200 N, 20-300 N, and 20-400 N). RESULTS: The PRBT technique demonstrated significantly less elongation (1.62 ± 0.25 mm) than the 4 other repair techniques after the first loading stage of 20 to 100 N (P < .05). All specimens in the 4 other groups developed a large gap (elongation ≥5 mm) at the 20- to 200-N loading stage. When overall biomechanical performance was examined, the PRBT group exhibited higher strength (20-400 N) and more mean loading cycles (984 ± 10) compared with the 4 other groups (P < .05). CONCLUSION: In this bovine model, PRBT biomechanically outperformed the other minimally invasive Achilles tendon repair techniques that were tested and could therefore meet the requirements of accelerated rehabilitation. CLINICAL RELEVANCE: The reduced tendency for premature rerupture and the overall improved biomechanical properties of PRBT suggest that ATR patients treated with PRBT may more readily complete early and aggressive postoperative rehabilitation protocols. In addition, they may have a lower risk of early irreversible suture failure.

Intramedullary hemostasis further reduces postoperative anemia in patients over 70 years old undergoing total hip arthroplasty.

PURPOSE: Postoperative anemia has been a threat to total hip arthroplasty patients. We introduced a novel medullary cavity hemostasis (MCH) technique and combined it with tranexamic acid (TXA) to prevent postoperative anemia in elder patients. This trial was conducted to evaluate the effectiveness and safety of this technique. METHODS: In this retrospective consecutive study, each group has 88 patients who were all over 70 years old. In the control group, patients were given TXA. In the experimental group, the MCH technique and same TXA application were used. RESULTS: The average of total blood loss, drainage volume, and hidden blood loss were significantly less in the experimental group. The postoperative hemoglobin (Hb) level was significantly higher in the experimental group (100.6 g/dL) than it is in the control group (81.4 g/dL). None of the patient has shown signs of prosthesis subsidence, periprosthetical osteolysis, or stem loosening during follow-ups in the average follow-up time of 3 years. CONCLUSION: We discovered that application of TXA alone is not sufficient to prevent postoperative moderate anemia in patients over 70 years old. Combination of TXA and MCH is an effective and safe way to alleviate the severity of postoperative anemia.

Optimization of the knot configuration for early accelerated rehabilitation after Achilles tendon rupture.

Background Panda Rope Bridge Technique (PRBT) was an new minimally invasive technique consisted of two bridge anchors (proximal anchors at calcaneus and distal anchors at myotendinous junction) and strong ropes (threads of the suture anchors) stretched between them, which was suitable for early accelerated rehabilitation of Achilles tendon rupture. However, the optimal knot configuration with PRBT was unknow. The purpose of this study was identify minimum number of half hitches necessary to maintain knot security for PRBT. Methods Using an Instron device we tested the effect of different knot configuration in two kinds of suture threads (Ethibond™ #5 and Ultrabraid™ #2). According to the result of it, we put the optimal knot configuration into Part 1 with PRBT test model and Part 2 with modified PRBT test model, to evaluate whether the optimal knot configuration could complete the cyclic loading test simulated early rehabilitation. Findings In the first part of the study, the optimal knot configuration of Ethibond™ #5 suture thread was the combination of three half hitches and one double throw half knot, and the optimal knot configuration of Ultrabraid™ #2 suture thread was the combination of five half hitches and one double throw half knot. In the second part of the study, only Ultrabraid™ #2 suture thread with optimal knot configuration had finished all test in Part 1. Interpretation The Ultrabraid™ #2 suture thread with optimal knot configuration was suitable for PRBT with early accelerated rehabilitation after Achilles tendon repair.

TGFß1 induces bone formation from BMP9-activated Bone Mesenchymal Stem Cells, with possible involvement of non-canonical pathways.

Reconstruction of bone defects is one of the most substantial and difficult clinical challenges in orthopedics. Transforming growth factor beta 1 (TGFß1) might play an important role in stimulating osteogenic differentiation of bone morphogenetic protein 9 (BMP9)-induced C3H10T1/2 mesenchymal stem cells. In our current study, we examined the potential synergy between TGFß1 and BMP9 in promoting the osteogenesis of C3H10T1/2 cells, and whether such effects could contribute to bone formation in vivo. Our experiment data indicated that TGFß1 could increase the expression of osteogenic markers and the formation of mineralized calcium nodules in, while suppressing the proliferation of, BMP9-induced C3H10T1/2 cells. Furthermore, mice intramuscularly injected with BMP9/TGFß1-transduced C3H10T1/2 cells into the gastrocnemius muscle on their tibiae developed ectopic bone masses with more mature osteoid structures, compared to those grafted with cells expressing BMP9/RFP. Subsequent mechanistic studies found that TGFß1-induced enhancement of osteogenesis in BMP9-overexpressing C3H10T1/2 cells was accompanied by augmented expression of heat shock protein 47 (HSP47), a collagen-specific molecular chaperone essential for collagen biosynthesis, and can be attenuated by pirfenidone, a known anti-fibrotic inhibitor. Interestingly, protein microarray analysis suggested that TGFß1/BMP9-dependent osteogenesis of C3H10T1/2 cells seemed to involve several non-canonical signaling pathways such as Janus kinase-signal transducer and activator of transcription, phosphoinositide-3-kinase-protein kinase B, and mitogen-activated protein kinase. These results provided further evidence that TGFß1 could promote bone formation from BMP9-induced C3H10T1/2 cells and shed important light on the underlying molecular mechanisms.

FGFR3 deficiency enhances CXCL12-dependent chemotaxis of macrophages via upregulating CXCR7 and aggravates joint destruction in mice.

OBJECTIVES: This study aims to investigate the role and mechanism of FGFR3 in macrophages and their biological effects on the pathology of arthritis. METHODS: Mice with conditional knockout of FGFR3 in myeloid cells (R3cKO) were generated. Gait behaviours of the mice were monitored at different ages. Spontaneous synovial joint destruction was evaluated by digital radiographic imaging and µCT analysis; changes of articular cartilage and synovitis were determined by histological analysis. The recruitment of macrophages in the synovium was examined by immunostaining and monocyte trafficking assay. RNA-seq analysis, Western blotting and chemotaxis experiment were performed on control and FGFR3-deficient macrophages. The peripheral blood from non-osteoarthritis (OA) donors and patients with OA were analysed. Mice were treated with neutralising antibody against CXCR7 to investigate the role of CXCR7 in arthritis. RESULTS: R3cKO mice but not control mice developed spontaneous cartilage destruction in multiple synovial joints at the age of 13 months. Moreover, the synovitis and macrophage accumulation were observed in the joints of 9-month-old R3cKO mice when the articular cartilage was not grossly destructed. FGFR3 deficiency in myeloid cells also aggravated joint destruction in DMM mouse model. Mechanically, FGFR3 deficiency promoted macrophage chemotaxis partly through activation of NF-κB/CXCR7 pathway. Inhibition of CXCR7 could significantly reverse FGFR3-deficiency-enhanced macrophage chemotaxis and the arthritic phenotype in R3cKO mice. CONCLUSIONS: Our study identifies the role of FGFR3 in synovial macrophage recruitment and synovitis, which provides a new insight into the pathological mechanisms of inflammation-related arthritis.

[Biomechanical comparison study of two ultra-strong sutures in repair of Achilles tendon via panda rope bridge technique].

OBJECTIVE: To compare the biomechanical properties of two ultra-strong sutures and suturing methods in panda rope bridge technique (PRBT) application, and provide guidance for clinical selection of suture threads and suture methods. METHODS: Forty Achilles tendons from bulls were randomly divided into 4 groups ( n=10) and transected at the 4 cm proximal to the tendon insertion. Groups A and B used Ethibond sutures (USP 5), the proximal end was fixed at the myotendious junction with Krackow sutures and the distal end was fixed through a calcaneus canal. Groups A and B had 4 and 8 threads through the stump plane, respectively. Groups C and D used Ultrabraid sutures (USP 2), the proximal end was fixed at the myotendious junction with Krackow sutures and the distal end was fixed in the calcaneus with two anchors. Groups C and D had 4 and 8 threads through the stump plane, respectively. The dynamic tensile forces of 20-100, 20-200, 20-300, and 20-400 N were tested respectively by using a dynamic tensile testing machine at 0.5 Hz for 250 cycles. After each stage of testing, the gap between stumps was measured with a caliper and the type of suture failure was recorded. RESULTS: After dynamic tensile forces of 20-100 N and 20-200 N, the gaps of the four groups arranged from small to large were groups D, B, C, and A. The differences between groups A and B and groups C and D were significant ( P<0.05). But after dynamic tensile forces of 20-300 N and 20-400 N, the gaps were more than 5 mm in all groups. The suture retention rates of the four groups after dynamic tensile forces of 20-100 N and 20-200 N were all 100%. The suture retention rates of groups A, B, C, and D were 0, 80%, 60%, and 100%, respectively after dynamic tensile forces of 20-300 N. The differences of suture retention rates between group A and groups B and D were significant ( P<0.05). There was no significant difference between groups B, C, and D ( P>0.05). After dynamic tensile forces of 20-400 N, the suture retention rates of groups A, B, C, and D were 0, 50%, 0, and 70%, respectively. There were significant differences between groups A and B and groups C and D ( P<0.05). CONCLUSION: Repairing Achilles tendon rupture via PRBT with 8 ultra-strong sutures through the stump plane can meet the mechanical requirements for walking by using ankle boots and heel pads in the early accelerated rehabilitation after operation.

[Corrigendum] All-trans retinoic acid restored the osteogenic ability of BMP9 in osteosarcoma through the p38 MAPK pathway.

Subsequently to the publication of the above paper, the authors have realized that the images presented in Fig. 1A were selected erroneously (essentially, the images for group 'AdBMP9 +++' were chosen to represent the group 'AdGFP'). A corrected version of Fig. 1, including the correct data for the experiments depicted in Fig. 1A, is shown opposite. Note that this change does not affect the results or the conclusions reported in this paper, and all the authors agree to this correction. The authors apologize to the Editor and to the readership of the Journal for any inconvenience caused. [the original article was published in International Journal of Oncology 50: 1363­1371, 2017; DOI: 10.3892/ijo.2017.3910].

The exosome-like vesicles from osteoarthritic chondrocyte enhanced mature IL-1ß production of macrophages and aggravated synovitis in osteoarthritis.

Synovitis, a common clinical symptom for osteoarthritis (OA) patients, is highly related to OA pathological progression and pain manifestation. The activated synovial macrophages have been demonstrated to play an important role in synovitis, but the mechanisms about macrophage activation are still not clear. In this study, we found that the exosome-like vesicles from osteoarthritic chondrocytes could be a new biological factor to stimulate inflammasome activation and increase mature IL-1ß production in macrophages. The degraded cartilage explants produced more exosome-like vesicles than the nondegraded ones, while the exosome-like vesicles from chondrocytes could enter into joint synovium tissue and macrophages. Moreover, the exosome-like vesicles from osteoarthritic chondrocytes enhanced the production of mature IL-1ß in macrophages. These vesicles could inhibit ATG4B expression via miR-449a-5p, leading to inhibition of autophagy in LPS-primed macrophages. The decreased autophagy promoted the production of mitoROS, which further enhanced the inflammasome activation and subsequent IL-1ß processing. Ultimately, the increase of mature IL-1ß may aggravate synovial inflammation and promote the progression of OA disease. Our study provides a new perspective to understand the activation of synovial macrophages and synovitis in OA patients, which may be beneficial for therapeutic intervention in synovitis-related OA patients.

Rmrp Mutation Disrupts Chondrogenesis and Bone Ossification in Zebrafish Model of Cartilage-Hair Hypoplasia via Enhanced Wnt/ß-Catenin Signaling.

Cartilage-hair hypoplasia (CHH) is an autosomal recessive metaphyseal chondrodysplasia characterized by bone dysplasia and many other highly variable features. The gene responsible for CHH is the RNA component of the mitochondrial RNA-processing endoribonuclease (RMRP) gene. Currently, the pathogenesis of osteochondrodysplasia and extraskeletal manifestations in CHH patients remains incompletely understood; in addition, there are no viable animal models for CHH. We generated an rmrp KO zebrafish model to study the developmental mechanisms of CHH. We found that rmrp is required for the patterning and shaping of pharyngeal arches. Rmrp mutation inhibits the intramembranous ossification of skull bones and promotes vertebrae ossification. The abnormalities of endochondral bone ossification are variable, depending on the degree of dysregulated chondrogenesis. Moreover, rmrp mutation inhibits cell proliferation and promotes apoptosis through dysregulating the expressions of cell-cycle- and apoptosis-related genes. We also demonstrate that rmrp mutation upregulates canonical Wnt/ß-catenin signaling; the pharmacological inhibition of Wnt/ß-catenin could partially alleviate the chondrodysplasia and increased vertebrae mineralization in rmrp mutants. Our study, by establishing a novel zebrafish model for CHH, partially reveals the underlying mechanism of CHH, hence deepening our understanding of the role of rmrp in skeleton development.

Complications in the Management of Acute Achilles Tendon Rupture: A Systematic Review and Network Meta-analysis of 2060 Patients.

BACKGROUND: Acute Achilles tendon rupture (ATR) has increased in the past decade, and many new treatments and rehabilitation regimens have been introduced. But major complications in ATR management remain an unsolved problem. PURPOSE: To compare the risk of major complications of acute ATR after different combinations of treatments and rehabilitation regimens. STUDY DESIGN: Systematic review and network meta-analysis. METHOD: The authors searched 4 databases (PubMed, Medline, Embase, and the Cochrane Library) from the date of inception until February 2018 for articles in English. The authors considered randomized controlled trials comparing interventions and rehabilitation protocols for acute ATR and restricted (1) interventions to nonoperative treatment, minimally invasive surgery, and open surgery and (2) rehabilitation protocols to accelerated rehabilitation and early immobilization. Major complications were assessed-namely, rerupture, deep infection, and deep vein thrombosis (DVT). Only patients with primary acute ATR were considered. Quality assessment was performed with the Cochrane "risk of bias" tool. A series of additional tests were conducted to ensure the validity of the results. RESULTS: Twenty-nine randomized controlled trials with 2060 patients were included in this Bayesian network meta-analysis. The mean incidence of overall major complications from all managements was 9.13% (median, 6.67%). The mean incidence rates of rerupture, deep infection, and DVT from all managements were 5%, 1.50%, and 2.67%, respectively. According to relative risk, nonoperative treatment combined with early immobilization was significantly associated with a higher risk of major complications. According to the surface under the cumulative ranking curve, minimally invasive surgery with accelerated rehabilitation had the highest possibility (79.7%) of being the best management with regard to minimizing major complications. CONCLUSION: For treating acute ATR, management combining minimally invasive surgery with accelerated rehabilitation had the highest possibility of being superior in terms of major complication risks, according to the surface under the cumulative ranking curve. Management combining nonoperative treatment with early immobilization was statistically associated with a higher risk of complications as compared with the other methods of management.

Treatment of acute achilles tendon rupture with the panda rope bridge technique.

INTRODUCTION: Although nonsurgical methods and many surgical techniques have been developed for repairing a ruptured Achilles tendon, there is no consensus on its best treatment. In this article, a novel minimally invasive technique called the Panda Rope Bridge Technique (PRBT) is described. METHODS: Patient with acute Achilles tendon rupture was operated on in the prone position. The PRBT begin with making the proximal bridge anchor (Krackow sutures in the myotendinous junction), the distal bridge anchor (two suture anchors in the calcaneus bone) and the ropes (threads of the suture anchors) stretched between the anchor sites. Then a small incision was made to debride and reattach the stumps of ruptured tendon. After the surgery, no cast or splint fixation was applied. All patients performed enhanced recovery after surgery (ERAS), which included immediate ankle mobilisation from day 1, full weight-bearing walking from day 5 to 7, and gradually take part in athletic exercises from 8 weeks postoperatively. RESULTS: PBRT was performed in 11patients with acute Achilles tendon rupture between June 2012 and June 2015. No wound infection, fistula, skin necrosis, sural nerve damage, deep venous thrombosis or tendon re-rupture was found. One year after the surgery, all patients reported 100 AOFAS ankle-hindfoot score points and the mean ATRS was 96.6. CONCLUSION: The PRBT is a simple, effective and minimally invasive technique, with no need for immobilisation of the ankle, making possible immediate and aggressive postoperative rehabilitation.

PTH 1-34 Ameliorates the Osteopenia and Delayed Healing of Stabilized Tibia Fracture in Mice with Achondroplasia Resulting from Gain-Of-Function Mutation of FGFR3.

Bone fracture healing is processed through multiple stages including the cartilaginous callus formation and its transition to bony callus. FGFR3 negatively regulates chondrogenesis and enhances osteogenesis during skeleton development. We previously found in mice carrying gain-of-function mutation of FGFR3 that FGFR3 delays the healing of un-stabilized fracture that heals mainly through endochondral ossification. Since fracture is regularly treated in clinics with rigid fixation, and stabilized fracture is healed largely through intramembranous ossification, we asked whether FGFR3, a key regulator of osteogenesis, also affect the regeneration of stabilized fracture. We found that gain-of-function mutation of FGFR3 inhibits the initiation of chondrogenesis and the subsequent bone formation. We further studied whether PTH1-34 can improve the osteopenia and delayed healing of the stabilized tibia fracture in mice with achondroplasia. Fracture healing was evaluated by radiography, micro-CT, biomechanical tests, histology, and real-time polymerase chain reaction (RT-PCR) analysis. We found that PTH 1-34 can alleviate the decreased bone mass and compromised architecture in ACH mice. Histological analysis revealed that administration of PTH1-34 increased the size of both the total callus and cartilaginous callus at 14 days after the surgery in ACH mice. RT-PCR data suggested that systemic PTH1-34 accelerated the initiation of chondrogenesis and chondrocyte maturation (earlier and higher levels of expression of chondrogenesis related markers) and enhanced the osteogenic differentiation in the fracture callus in ACH mice. These results indicate that the PTH1-34 administration resulted in an enhanced callus formation during bone fracture healing in ACH mice, which is at least in part mediated by an increase of cartilaginous callus at early stage and the promotion of bone formation in bony callus. In summary, in this study we revealed that FGFR3 delays the regeneration of stabilized fracture by inhibiting both the chondrogenesis and osteogenesis, and PTH1-34 treatment can improve the dysregulated bone metabolism and delayed bone injury healing resulting from gain-of-function mutation of FGFR3.

miR­494 inhibits cell proliferation and metastasis via targeting of CDK6 in osteosarcoma.

Tumorigenesis is a multistep process involving various cell growth­associated factors. Accumulated evidence indicates that the disordered regulation of microRNAs (miRNAs) contributes to tumorigenesis. However, the detailed mechanism underlying the involvement of miRNAs in oncogenesis remains to be fully elucidated. In the present study, the repressed expression of microRNA (miR)­494 was identified in 18 patients with osteosarcoma (OS) and OS cell lines, compared with corresponding controls. To determine whether deregulated miR­494 exerts tumor­suppressive effects in the development of OS, the effects of miR­494 on cell proliferation and metastasis were evaluated. It was found that the restoration of miR­494 in MG­63 and U2OS cells led to inhibited cell proliferation and attenuated migratory propensity in vitro, determined through analysis using MTT, colony formation and Transwell assays. In addition, overexpression of miR­494 markedly suppressed the tumor volume and weight in vivo. In accordance, the ectopic expression of miR­494 induced cell cycle arrest at the G1/S phase in OS cells. Bioinformatics analysis and luciferase reporter assays were performed to investigate the potential regulatory role of miR­494, the results of which indicated that miR­494 directly targeted cyclin­dependent kinase 6 (CDK6). Of note, the data obtained through reverse transcription­quantitative polymerase chain reaction and western blot analyses suggested that the elevated expression of miR­494 resulted in reduced mRNA and protein expression levels of CDK6. Taken together, these findings indicated that the miR­494/CDK6 axis has a significant tumor­suppressive effect on OS, and maybe a diagnostic and therapeutic target for the treatment of OS.

Bone morphogenetic protein 9 stimulates callus formation in osteoporotic rats during fracture healing.

Fracture healing involves the coordinated actions of multiple cytokines. Bone morphogenetic protein 9 (BMP9) is an important factor in bone formation. The present study aimed to investigate the osteogenic potential of bone marrow stem cells (BMSCs) in response to adenoviral (Ad)BMP9, and the early fracture repair properties of AdBMP9 in surgically­created fractures in osteoporotic rats. Alkaline phosphatase (ALP) activity was assayed and matrix mineralization was examined by Alizarin Red S staining. mRNA and protein expression levels of BMP9, runt­related transcription factor 2 (RUNX2) and type 1 collagen (COL­1) were detected in vitro and in vivo. Femoral bone mineral density was assessed for osteoporosis in ovariectomized rats. An open femora fracture was subsequently created, and gelatin sponges containing AdBMP9 were implanted. The femora were harvested for radiographical, micro­computed tomography, biomechanical and histological analysis 4 weeks later. BMP9 successfully increased ALP activity and induced mineralized nodule formation in BMSCs. BMP9 in gelatin sponges demonstrated marked effects on microstructural parameters and the biomechanical strength of bone callus. In addition, it upregulated the expression levels of RUNX2 and COL­1. AdBMP9 in gelatin sponges significantly mediated callus formation, and increased bone mass and strength in osteoporotic rats with femora fractures. The results of the present study suggested that BMP9 enhanced callus formation and maintained early mechanical stability during fracture healing in osteoporotic rats, implicating it as a potential novel therapeutic target for fracture healing.

All-trans retinoic acid restored the osteogenic ability of BMP9 in osteosarcoma through the p38 MAPK pathway Corrigendum in /10.3892/ijo.2019.4817.

Osteosarcoma (OS) is the most common malignant bone tumour and is considered to be a disease caused by a dysfunction in differentiation. Bone morphogenetic protein 9 (BMP9) is the most potent osteogenic factor in mesenchymal stem cells, but it cannot induce osteogenic differentiation in OS cells; this might be one of the determinants in the pathogenesis of OS. All-trans retinoic acid (ATRA) can induce osteogenic differentiation of OS cells and potentiate BMP9-induced osteogenesis in preadipocytes. However, the concomitant effect of ATRA and BMP9 in OS cells is unclear; therefore, in the present study, we focused on this topic. The results showed that BMP9 significantly promoted the proliferation of human OS 143B cells and did not induce osteogenic differentiation of cells in vitro (p<0.01). ATRA inhibited proliferation and induced osteogenesis in 143B cells; these effects could be enhanced by BMP9 overexpression (p<0.05). ATRA could significantly increase the level of phosphorylated p38 MAPK (p-p38) in 143B cells, while BMP9 did not have any significant effect. Notably, BMP9 overexpression enhanced the ability of ATRA to increase the levels of p-p38. Both the osteogenic differentiation and the anti-proliferative activity of BMP9 in the presence of ATRA decreased upon treatment with a specific inhibitor of p38 MAPK (SB203580) (p<0.01). This study indicates that the osteogenic differentiation ability of BMP9 in 143B cells can be restored by ATRA, and the combination of BMP9 and ATRA generated a stronger anti-proliferative effect on 143B cells than ATRA alone. This result may be due to the activation of the p38 MAPK pathway.

A Bayesian network meta-analysis of three different surgical procedures for the treatment of humeral shaft fractures.

BACKGROUND: The optimal surgical procedure for humeral shaft fractures remains a matter of debate. We aimed to establish the optimum procedure by performing a Bayesian network meta-analysis. METHODS: PubMed, EMBASE, the Cochrane Library, and Medline were searched for both randomized controlled trials and prospective studies of surgical treatment for humeral shaft fractures. The quality of the included studies was assessed according to the Cochrane Collaboration's "Risk of bias". RESULTS: Seventeen RCTs or prospective studies were included in the meta-analysis. The pooled results showed that the occurrence rate of radial nerve injury was lowest for minimally invasive plate osteosynthesis (MIPO; SUCRA probability, 95.1%), followed by open reduction and plate osteosynthesis (ORPO; SUCRA probability, 29.5%), and was highest for intramedullary nailing (IMN; SUCRA probability, 25.4%). The aggregated results of pairwise meta-analysis showed no significant difference in radial nerve injury rate when comparing ORPO versus IMN (OR, 1.92; 95% CI, 0.96 to 3.86), ORPO versus MIPO (OR, 3.38; 95% CI, 0.80 to 14.31), or IMN versus MIPO (OR, 3.19; 95% CI, 0.48 to 21.28). Regarding the nonunion, SUCRA probabilities were 90.5%, 40.2%, and 19.3% for MIPO, ORPO, and IMN, respectively. The aggregated results of a pairwise meta-analysis also showed no significant difference for ORPO versus IMN (OR, 0.83; 95% CI, 0.41 to 1.69), ORPO versus MIPO (OR, 2.42; 95% CI, 0.45 to 12.95), or IMN versus MIPO (OR, 2.49; 95% CI, 0.35 to 17.64). CONCLUSION: The current evidence indicates that MIPO is the optimum choice in the treatment of humeral shaft fractures and that ORPO is superior to IMN.