BACKGROUND: Simple bone cement is easy to cause refracture of adjacent vertebra due to its high hardness. Currently, a material that can reduce the incidence of adjacent vertebra fracture is urgently needed. OBJECTIVE: To observe the clinical efficacy of percutaneous vertebroplasty using mineralized collagen modified bone cement. METHODS: Totally 60 patients with fresh single osteoporotic vertebral compression fractures who underwent percutaneous vertebroplasty were randomly divided into two groups, with 30 cases in each group. Patients in the simple bone cement group were given polymethyl methacrylate bone cement. Patients in the modified bone cement group were given mineralized collagen modified bone cement mixed with artificial bone repair material and simple polymethyl methacrylate bone cement. All patients signed the informed consent. This study was approved by the Hospital Ethics Committee. The follow-up time was 6-12 months. The clinical effect was assessed by the visual analogue scale, Oswestry Disability Index, Cobb angle and percentage of vertebral anterior edge height before surgery, at 2 days after surgery and during the last follow-up. Postoperative complications were recorded. RESULTS AND CONCLUSION: (1) All patients underwent successful operation. A total of four patients were found to have different degrees of bone cement leakage, and none of the patients presented obvious clinical discomfort symptoms. (2) Compared with pre-operation, visual analogue scale and Oswestry Disability Index were significantly improved (P < 0.05); the height of the anterior border of the injured vertebrae and the Cobb angle of the kyphosis were not significantly changed (P > 0.05) at 2 days after operation and during the last follow-up in the two groups. There were no significant differences in above indexes between the two groups at the same time point (P > 0.05). (3) The number of adjacent fractures in the simple bone cement group was more than that in the modified bone cement group, but there was no statistically significant difference in the incidence of adjacent vertebral fractures between the two groups (P > 0.05). (4) It is confirmed that compared with simple bone cement, mineralized collagen modified bone cement has no obvious disadvantages. In addition, mineralized collagen modified bone cement can give better biological properties while ensuring the strength of bone cement support and reducing pain. Further studies are needed to reduce the incidence of adjacent vertebral fractures.

Objective:To investigate the biomechanical properties of anterior pelvic ring external fixators of two new configurations [iliac crest (IC)+anterior inferior iliac spine (AIIS), anterior superior iliac spine(ASIS)+AIIS] in the treatment of Tile type C1 pelvic fracture.Methods:A 3-dimensional finite element model of Tile type C1 pelvic ring injury (unilateral longitudinal sacral fracture and ipsilateral pubic fracture) was produced. The pelvis was fixed with external fixators of IC, AIIS, combination of IC and AIIS, combination of ASIS and AIIS, and S 1 sacroiliac screw in 5 types of models. In the simulated bipedal standing position and semi-recumbent position, the longitudinal displacement and back rotation angle displacement of the midpoint on the upper surface of S 1 were quantified and compared. Under the simulated left-right compression load state, the lateral displacements of the highest point of the lateral sacral fracture and the highest point of the lateral pubic fracture end were quantified and compared. Under the simulated anterior-posterior shear load state, the backward displacements of the highest point of the lateral sacral fracture end and the highest point of the lateral pubic fracture end were quantified and compared. Results:(1) In the simulated bipedal standing position under the vertical and longitudinal load state, the results of the longitudinal downward displacement of the midpoint on the upper surface of S 1 were consistent with the backward rotation angle displacement, and the order from largest to smallest was IC, AIIS, ASIS+AIIS, IC+AIIS and S 1 sacroiliac screw. The longitudinal downward displacement of IC was significantly larger than that of other models. The longitudinal downward displacement and backward rotation angle displacement of ASIS+AIIS and IC+AIIS were similar, and the latter was smaller. (2) In the simulated semi-recumbent position under the vertical and longitudinal load state, the results of the longitudinal downward displacement and backward rotation angle displacement of the midpoint on the upper surface of S 1 were also consistent, and the order from largest to smallest was IC, AIIS, ASIS+AIIS, IC+AIIS and S 1 sacroiliac screw. (3) Under the simulated left-right compression load state, the results of the lateral displacement of the highest point of the lateral sacral fracture end were consistent with that of the highest point of the lateral pubic fracture end, and the order from largest to smallest was S 1 sacroiliac screw, IC, AIIS, ASIS+AIIS and IC+AIIS. Among them, Among them, The lateral displacement of S 1 sacroiliac screw and IC was larger. The lateral displacement of ASIS+AIIS and IC+AIIS was similar, and the latter was smaller, significantly smaller than that of other models. (4) Under the simulated anterior-posterior shear load state, the results of the backward displacement of the highest point of the lateral sacral fracture end and the highest point of the lateral pubic fracture end were also consistent, and the order from largest to smallest was IC, AIIS, ASIS+AIIS, IC+AIIS and S 1 sacroiliac screw. Among them, the backward displacement of IC and AIIS was larger. The backward displacement of ASIS+AIIS and IC+AIIS was similar, and the latter was smaller. Conclusions:For type C1 pelvic fracture, the biomechanical stabilities of IC+AIIS and ASIS+AIIS are superior to those of IC or AIIS, with ASIS+AIIS being slightly inferior to IC+AIIS. Compared with S 1 sacroiliac screw, IC or AIIS, the lateral stabilities of IC+AIIS and ASIS+AIIS are particularly prominent. The two new external fixator configurations in this study are worthy of clinical application.

ObjectiveTo investigate the protective effect of folic acid against cholestatic liver injury in mice induced by bis（2-ethylhexyl） phthalate （DEHP） exposure and its mechanism. MethodsICR mice were randomly divided into control group， high-dose folic acid （H-FA） group， DEHP group， DEHP+low-dose folic acid （DEHP+L-FA） group， and DEHP+high-dose folic acid （DEHP+H-FA） group， with 6 mice in each group. The mice in the H-FA group， the DEHP+L-FA group， and the DEHP+H-FA group were given folic acid by gavage at the corresponding dose， and those in the control group and the DEHP group were given an equal volume of PBS solution by gavage. After 2 hours， the mice in the DEHP group， the DEHP+L-FA group， and the DEHP+H-FA group were given corn oil containing 200 mg/kg DEHP， and those in the control group and the H-FA group were given an equal volume of pure corn oil， by gavage for 4 weeks. Body weight and food intake were recorded every day， and blood and liver tissue samples were collected. A biochemical analyzer was used to measure the serum levels of total bile acid （TBA） and alkaline phosphatase（ALP）； HE staining was used to observe the histopathological changes of liver tissue； kits were used to measure the content of malondialdehyde （MDA） and superoxide dismutase （SOD） in the liver； LC-MS/MS was used to measure serum bile acid profiles； Western blot was used to measure the expression levels of proteins associated with hepatic bile acid metabolism. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the control group， the daily food intake of the mice in the DEHP group decreased significantly， and the body weight decreased significantly from day 10 （P<0.05）， and compared with the DEHP group， the DEHP+L-FA group and the DEHP+H-FA group had basically unchanged body weight and daily food intake （P>0.05）. Compared with the control group， the DEHP group had significant increases in liver weight index and the serum levels of TBA and ALP （all P<0.05）， with enlarged portal area， bile duct deformity and hyperplasia， and a small amount of inflammatory cell infiltration in liver tissue； compared with the DEHP group， the DEHP+L-FA group and the DEHP+H-FA group had a significant reduction in liver weight index （P<0.01）， and the DEHP+H-FA group had significant reductions in the serum levels of TBA and ALP （P<0.05）， with a significant improvement in liver histomorphology and structure after folic acid intervention. Compared with the control group， the DEHP group had a significant reduction in the content of SOD （P<0.05） and a significant increase in the content of MDA in the liver （P<0.01）， and compared with the DEHP group， the DEHP+H-FA group had significant reductions in the content of MDA and SOD （P<0.05）. Compared with the control group， the DEHP group had significant increases in the serum levels of α-muricholic acid （α-MCA），β- muricholic acid （β-MCA），deoxycholic acid （DCA）， lithocholic acid （LCA）， taurocholic acid （TCA）， taurodeoxycholic acid （TDCA）， tauroursodeoxycholic acid （TUDCA）， tauro-β-muricholic acid （T-β-MCA）， tauro-α-muricholic acid （T-α-MCA）， taurohyodeoxycholic acid （THDCA）， and taurolithocholic acid （TLCA） （P<0.05） and a significant reduction in ursodeoxycholic acid （UDCA）（P<0.05）； compared with the DEHP group， the DEHP+H-FA group had significant reductions in the serum levels of DCA， LCA， TCA， TDCA， TUDCA， T-β-MCA， T-α-MCA， THDCA， and TLCA （P<0.05）. Compared with the control group， the DEHP group had significant increases in the protein expression levels of FXR and CYP3A11 in the liver （P<0.01） and significant reductions in the protein expression levels of CYP7A1 and MRP2 （P<0.01）； compared with the DEHP group， the DEHP+L-FA group and the DEHP+H-FA group had significant reductions in the protein expression levels of FXR and CYP3A11 in the liver （P<0.05） and a significant increase in the protein expression level of MRP2 （P<0.05）， and the DEHP+H-FA group had a significant increase in the protein expression level of CYP7A1 （P<0.05）. ConclusionFolic acid has a protective effect against cholestatic liver injury in mice induced by DEHP exposure， possibly by regulating bile acid synthesis， catabolism， and transport and maintaining bile acid homeostasis.