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BackgroundIn this study, we aimed to investigate the risk factors contributing to secondary vertebral compression fractures (SVCF) in patients undergoing percutaneous vertebroplasty (PVP) or kyphoplasty (PKP) due to osteoporotic vertebral compression fracture (OVCF).Material/MethodsBetween January 2010 and December 2017, 650 patients with regular follow-up were identified and retrospectively analyzed in this study. Of these patients, 410 patients underwent PVP and 240 patients underwent PKP surgery. Patients were followed for 24 months on average, ranging from 6 months to 36 months follow-up. Possible risk factors screened for were age, gender, regional distribution, outdoor activity (ODA), bone mineral density (BMD), surgical methods (unilateral or bilateral), bone cement dose, bone cement leakage, chronic disease history, postoperative anti-osteoporosis treatment, and level of preoperative OVCF. Logistic regression analysis was applied to determine potential risk factors.ResultsAs a result, 102 patients (15.7%) suffered SVCF after PVP/PKP surgery at the last follow-up. Binary logistic regression model showed that older age increased the risk of developing SVCF [odds ratio (OR)=2.48, P=0.031] while high-level BMD (OR=0.31, P<0.001) and ODA (OR=0.38, P=0.001) decreased the risk. Binary logistic regression model showed the following: Logit (P)=1.03+0.91X1–1.18X2–0.97X3 (X1=age, OR=2.48, P=0.031; X2=BMD, OR=0.31, P<0.001; X3=ODA, OR=0.38, P=0.001).ConclusionsIn conclusion, older age and lower BMD were identified as risk factors of SVCF for OVCF patients following PVP/PKP surgery, whereas more ODA played a protective role in SVCF development.

Given the severity of today’s environmental issues, companies are increasingly making green concepts a key component of their operational strategies. As an essential complement to corporate environmental strategy, employees’ green behavior has received attention from all sectors of society. Based on resource conservation theory, this study explores the formation mechanism of employees’ green behaviors in enterprises starting from two green management tools: green human resource management (HRM) practices and green transformational leadership. Through two-stage questionnaire research, 296 sample data points were obtained, and the research hypotheses were tested by using linear regression analysis. The results showed that green HRM practices in enterprises enhance employees’ green mindfulness and thus stimulate their green behaviors and that green transformational leadership and green self-efficacy play a positive moderating role in the above relationship. These results support the applicability of resource conservation theory in green management and suggest that green HRM practices and green transformational leadership can be used together in the process of green management.

As a minimally invasive surgery, percutaneous cement discoplasty (PCD) is now contemplated to treat lumbar disc degeneration disease in elder population. Here, we investigated whether the osteogenic mineralized collagen (MC) modified polymethylmethacrylate (PMMA) cement could be a suitable material in PCD surgery. Injectability, hydrophilicity and mechanical properties of the MC-modified PMMA (PMMA-MC) was characterized. The introduction of MC did not change the application and setting time of PMMA and was easy to be handled in minimally invasive operation. Hydrophilicity of PMMA-MC was greatly improved and its elastic modulus was tailored to complement mechanical performance of bone under dynamic stress. Then, PCD surgery in a goat model with induced disc degeneration was performed with implantation of PMMA-MC or PMMA. Three months after implantation, micro-computed tomography analysis revealed a 36.4% higher circumferential contact index between PMMA-MC and bone, as compared to PMMA alone. Histological staining confirmed that the surface of PMMA-MC was in direct contact with new bone, while the PMMA was covered by fibrous tissue. The observed gathering of macrophages around the implant was suspected to be the cause of fibrous encapsulation. Therefore, the interactions of PMMA and PMMA-MC with macrophages were investigated in vitro. We discovered that the addition of MC could hinder the proliferation and fusion of the macrophages. Moreover, expressions of fibroblast-stimulating growth factors, insulin-like growth factor, basic fibroblast growth factor and tumor necrosis factor-β were significantly down-regulated in the macrophages cocultured with PMMA-MC. Together, the promoted osteointegration and reduced fibrous tissue formation observed with PMMA-MC material makes it a promising candidate for PCD surgery.

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