Biomechanical analysis of bridge combined fixation system as a novel treatment for the fixation of type A3 distal femoral fractures.

Background: To compare the biomechanical parameters of AO/OTA type A3 distal femoral fractures fixed bilaterally with a bridge combined fixation system (BCFS) and lateral locking compression plate + locking reconstruction plate (LCP + LRP). Methods: Twelve A3 distal femoral fracture models with medial cortical defects of the distal femur were created using synthetic femoral Sawbones. BCFS and LCP + LRP were used for bilateral fixation, with six in each group. Axial compression and torsion tests were performed on the two groups of fracture models to determine their stiffness during axial compression and the Torsional stiffness during torsion tests. Axial compression failure tests were performed to collect the vertical loads of the ultimate failure tests. Results: In the test conducted on the fixed type A3 distal femoral fracture models, the axial stiffness in the BCFS group (group A) (1,072.61 ± 113.5 N/mm) was not significantly different from that in the LCP + LRP group (group B) (1,184.13 ± 110.24 N/mm) (t = 1.726, P = 0.115), the Torsional stiffness in group A (3.73 ± 0.12 N.m/deg) was higher than that in group B (3.37 ± 0.04 N.m/deg) (t = 6.825, P < 0.001),and the ultimate failure test of type A3 fracture model showed that the vertical load to destroy group A fixation (5,290.45 ± 109.63 N) was higher than that for group B (3,978.43 ± 17.1 N) (t = 23.28, P < 0.05). Notably, intertrochanteric fractures occurred in groups A and B. Conclusions: In the fixation of type A3 distal femoral fractures, the anti-axial compression of the BCFS group was similar to that of the LCP + LRP group, but the anti-torsion was better.

Piperine improves the sensitivity of osteosarcoma cells to doxorubicin by inducing apoptosis and inhibiting the PI3K/AKT/GSK-3ß pathway.

BACKGROUND: Osteosarcoma is a primary bone malignancy associated with the highest incidence rate. Chemotherapy for osteosarcoma has not substantially changed, and survival of patients with metastatic tumours has reached a plateau. Doxorubicin (DOX) is a broad-spectrum anti-osteosarcoma drug; however, its application is limited due to its high cardiotoxicity. Piperine (PIP) has been verified to drive certain cancer cell death and increases chemosensitivity of DOX. However, the effects of PIP in promoting the chemosensitivity of osteosarcoma to DOX have not been studied. METHODS: We examined the combined effect of PIP and DOX on U2OS and 143B osteosarcoma cells. CCK-8 assays, scratch assays, flow cytometry analysis, and western blotting were performed. Furthermore, the effect of PIP combined with DOX on osteosarcoma tumours was observed in vivo using nude mice. RESULTS: PIP can increase the chemosensitivity of U2OS and 143B cells to DOX. Both in vitro and in vivo results showed the dramatic inhibition of cell proliferation and tumour growth by the combined therapy group compared to monotherapy groups. Apoptosis analysis revealed that PIP augments DOX-induced cell apoptosis by upregulating BAX and P53 expression, as well as reducing Bcl-2 expression. Furthermore, PIP also attenuated the initiation of the PI3K/AKT/GSK-3ß signaling pathway in osteosarcoma cells by altering the expression levels of P-AKT, P-PI3K and P-GSK3ß. CONCLUSIONS: This study revealed for the first time that PIP can potentiate the sensitivity and cytotoxicity of DOX during osteosarcoma therapy in vitro and in vivo, which probably achieved by inhibiting the PI3K/AKT/GSK-3ß signalling pathway.

Effectiveness and Biomechanical Analysis of the Ortho-Bridge System on Femoral Fracture Healing: A Retrospective Analysis.

Background: Among the surgical methods for femoral fractures, the Ortho-Bridge System (OBS) appears to heal fractures via an uncommon process. We compared its effectiveness and biomechanical aspects to those of a locking compression plate (LCP) and explained the healing process demonstrated by the OBS. Methods: Eleven femoral shaft fracture cases treated with OBS between July 2017 and May 2020 were retrospectively reviewed. Clinical and radiographic data were collected during regular postoperative follow-up visits and assessed via the Harris Hip Score and Knee Society Score. We performed biomechanical experiments of OBS. We simulated different fracture conditions and selected appropriate screw holes at the fracture's far and near segments. The OBS module was placed according to the position of LCP's locking hole at both ends of the fracture; then, a static three-point bending test was performed. Results: All patients had contralateral callus growth with secondary fracture healing. Healing time was 3-5 months with excellent hip and knee function. When the key screw distance was 22-34 mm, the OBS was significantly less stiff than the LCP (P < 0.05). The stiffness of LCP and OBS decreased significantly when the key screw distance was 49-82 mm, with the LCP being slightly stronger (P < 0.05). Conclusions: Femoral shaft fracture treatment with OBS demonstrated secondary healing. When the distance between the key screws was 20-40 mm, the elasticity was higher in OBS than in LCP, possibly producing axial micro-motion to stimulate callus formation and promote fracture healing, which differ from the plate's primary healing process.

Femoral periprosthetic fracture treatment using the Ortho-Bridge System: a biomechanical study.

BACKGROUND: We undertook a comparative biomechanical study of type B1 fractures around femoral prostheses following cemented hip arthroplasty using the Ortho-Bridge System (OBS) and a locking compression plate/locking attachment plate structure (LCP + LAP). We aimed to investigate the biomechanical characteristics and advantages of the OBS compared with LCP + LAP when treating this fracture type. METHODS: An OBS fixation model was designed based on OBS and LCP + LAP fixation characteristics. The LCP + LAP combination (Group A) and three different OBS combinations (Groups B, C, and D) were used to fix a B1 fracture model with a femoral periprosthetic fracture. Axial compression and torsion experiments were then performed using simple and comminuted fracture models. The axial compression failure experiment was carried out, and the model stiffness during axial compression, torsion angle in torsion test, and vertical load in the final failure test were collected. RESULTS: When simulating simple oblique fractures, no significant difference was found among the four groups in terms of stiffness in the axial compression experiment (P = 0.257). The torsion angle of the LCP + LAP system was significantly higher compared with the OBS system (P < 0.05). When simulating a comminuted fracture, the experimental data for axial compression showed that the rigidity measurements of the three combinations of the OBS system were higher compared with the LCP + LAP system (P = 0.000) and that the torsion angles of three combinations of the OBS system were smaller compared with the LCP + LAP system (P < 0.05). In the axial compression failure test, the fixed failure mode of the LCP + LAP system was the destruction of the contact cortex at the fracture site, whereas the failure modes in the three OBS combinations involved fracture around the screws above the osteotomy and destruction of the contact cortex at the fracture site. CONCLUSIONS: The findings revealed that the OBS produced superior biomechanical outcomes compared with LCP + LAP, especially for the bridging two-rod dual cortex. According to the performance observed after model axial compression destruction, the OBS was fixed and provided greater stress dispersion, which might make it more suitable for facilitating early functional movement and avoiding the failure of internal fixation.

S-Type Posterolateral Approach for Open Reduction and Internal Fixation of Pronation External Rotation Ankle Fractures: Improved Visualisation of the Posterior Joint and the Lateral Malleolus.

Pronation external rotation (PER) fractures are unstable ankle fractures that require anatomically stable fixation. However, due to the long distance between the fibula and the posterior malleolus in PER IV, existing approaches may make it difficult for the fixation of the associated posterior joint and the lateral malleolus. We describe an S-type posterolateral approach for the open reduction and internal fixation of posterior malleolar fractures with an associated lateral malleolar fracture in PER IV.

Wnt/ß­catenin signaling modulates piperine­mediated antitumor effects on human osteosarcoma cells.

The plant extract piperine is used as a traditional Chinese medicine due to its anti­inflammatory effects and efficacy against numerous types of cancer. The aim of the present study was to investigate the antitumor mechanism of piperine in human osteosarcoma U2OS and 143B cell lines. The effects of piperine on cell apoptosis and invasion of human osteosarcoma cells were assessed using flow cytometry and Transwell assays. Moreover, western blotting was used to measure the effects of piperine on the protein expression levels of the metastasis markers matrix metalloproteinase­2 (MMP­2) and vascular endothelial growth factor (VEGF). In addition, the involvement of the Wnt/ß­catenin signaling pathway in modulating the effects of piperine was examined via western blot analysis. The results of MTT and Transwell invasion assays indicated that piperine treatment dose­dependently reduced U2OS and 143B cell viability and invasion. Furthermore, a significant reduction was identified in MMP­2, VEGF, glycogen synthase kinase­3ß and ß­catenin protein expression levels, as well as the expression levels of their target proteins cyclooxygenase­2, cyclin D1 and c­myc, in U2OS cells after piperine treatment. In addition, similar results were observed in 143B cells. Therefore, the present study demonstrated the efficacy of piperine in osteosarcoma, and identified that the Wnt/ß­catenin signaling pathway may modulate the antitumor effects of piperine on human U2OS and 143B cells.

A comprehensive analysis for associations between multiple microRNAs and prognosis of osteosarcoma patients.

BACKGROUND: Osteosarcoma (OS) is the most common malignant primary bone tumor occurring in children and young adults, which occupies the second important cause of tumor-associated deaths among children and young adults. Recent studies have demonstrated that many microRNAs (miRNAs) have abnormal expression in OS, and can function as prognostic factors of OS patients. However, no previous studies have comprehensively analyzed the relationship between multiple miRNAs and prognosis of OS patients. METHODS: A total of 63 OS patients were retrospectively enrolled. The clinical characteristics were collected, and the expression levels of miRNA-21, miRNA-30c, miRNA-34a, miRNA-101, miRNA-133a, miRNA-214, miRNA-218, miRNA-433 and miRNA-539 in tumor tissues were measured through quantitative real-time polymerasechain reaction. Kaplan-Meier analysis was used to perform univariate survival analysis, and Cox regression model was used to perform multivariate survival analysis which included the variables with P < 0.1 in univariate survival analysis. RESULTS: The cumulative survival for 1, 2 and 5 years was 90.48%, 68.25% and 38.10%, respectively, and mean survival time was (45.39 ± 3.60) months (95% CI [38.34-52.45]). Kaplan-Meier analysis demonstrated that TNM stage, metastasis or recurrence, miRNA-21, miRNA-214, miRNA-34a, miRNA-133a and miRNA-539 were correlated with cum survival, but gender, age, tumor diameter, differentiation, miRNA-30c, miRNA-433, miRNA-101 and miRNA-218 were not. Multivariate survival analysis demonstrated that miRNA-21 (hazard ratio (HR): 3.457, 95% CI [2.165-11.518]), miRNA (HR: 3.138, 95% CI [2.014-10.259]), miRNA-34a (HR: 0.452, 95% CI [0.202-0.915]), miRNA-133a (HR: 0.307, 95% CI [0.113-0.874]) and miRNA-539 (HR: 0.358, 95% CI [0.155-0.896]) were independent prognostic markers of OS patients after adjusting for TNM stage (HR: 2.893, 95% CI [1.496-8.125]), metastasis or recurrence (HR: 3.628, 95% CI [2.217-12.316]) and miRNA-30c (HR: 0.689, 95% CI [0.445-1.828]). CONCLUSIONS: High expression of miRNA-21 and miRNA-214 and low expression of miRNA-34a, miRNA-133a and miRNA-539 were associated with poor prognosis of OS patients after adjusting for TNM stage, metastasis or recurrence and miRNA-30c.