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BACKGROUND:Previous literature reported that the fusion cage moved more than 2 mm from its original position,which means that the fusion cage moved backward.At present,clinical observation has found that the factors leading to the displacement of the fusion cage are complex,and the relationship between these factors and the cage retropulsion is not clear. OBJECTIVE:To explore the risk factors related to cage retropulsion after lumbar interbody fusion. METHODS:Retrospective analysis was conducted in 200 patients who underwent transforaminal lumbar interbody fusion surgery with a polyetheretherketone interbody fusion from February 2020 to February 2022.According to the distance from the posterior edge of the vertebral fusion cage to the posterior edge of the vertebral body after the operation(the second day after the removal of the drainage tube)and 1,3,6 and 12 months after the operation,patients were divided into cage retropulsion group(≥2 mm)and cage non-retropulsion group(<2 mm).The factors that may affect cage retropulsion,such as age,gender,body mass index,bone mineral density,operation time,bleeding,endplate injury,preoperative and postoperative interbody height,cage implantation depth,cage size,and segmental anterior convexity angle,were analyzed by univariate and logistic regression analysis. RESULTS AND CONCLUSION:(1)Posterior displacement of the fusion cage occurred in 15 cases(15/200).The differences in basic information such as age and body mass index between the two groups were not statistically significant.(2)The results of the univariate analysis were that gap height difference,time to wear a brace,segmental anterior convexity angle difference,bone mineral density,and age were related to posterior migration of the cage.(3)The results of logistic regression analysis were that cage size,endplate injury condition,and depth of cage implantation were risk factors for cage retropulsion.(4)These findings suggest that cage retropulsion after lumbar interbody fusion is caused by multiple factors,including segmental anterior convexity angle difference,bone mineral density,cage size,endplate damage,time to wear a brace,and depth of cage implantation.
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Objective:To isolate SD rat adipose-derived stem cells(ASCs)by suspended explant culture method.Methods: The healthy rat inguinal fat pads were obtained.The SD rat ASCs were isolated by suspended explant culture method and explant adherent culture method.The growth status and morphology were observed.The growth curve and cell surface markers CD29,CD44,CD45 of the 3rd passage cells were analyzed respectively by CCK-8,immunocytochemistry;the 3rd passage cells were induced individually by adipogenic differentiation medium and osteogenic differentiation medium,and cells were examined by oil red O staining and alizarin red staining.Results: The SD rat ASCs obtained by the two methods exhibited a spindle-shaped appearance and could rapidly expand.The cell growth curves were typical of S type.Immunocytochemistry analysis revealed that the third passage of SD rat ASCs were positive for CD29,CD44,but were negative for CD45.SD rat ASCs were positive for oil red O staining at 14 days after adipogenic induction,and positive for alizarin red staining at 14 days after osteogenic induction.Conclusion: Isolation of SD rat ASCs by suspended explant culture method is successfully established.The method is simple.It provides a new method for the isolation of SD rat ASCs in vitro.
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Objective To study the effect of cryopreservation on some biological properties of rabbit adipose -de-rived mesenchymal stem cells (rADMSCs).Methods rADMSCs culture was isolated by tissue explants adherent meth-od.Morphology of the primary cells was observed by inverted microscopy .Immunophenotypes of the rADMSCs were deter-mined using flow cytometry .The third passage cells were preserved in liquid nitrogen for 6 months, and then were thawed , and subcultured to passage 7.The growth curves of the cryopreserved cells were analyzed by MTT assay , and the cryopre-served cells were cultured in adipogenic and osteogenic medium , with non-cryopreserved rADMSCs as a control group .The adipogenic and osteogenic abilities of the rADMSCs were evaluated by oil red O staining , alizarin red staining and alkaline phosphatase activity assay , respectively.Results The rADMSCs cultured in vitro exhibited a spindle-shaped appearance and rapid growth expansion .Flow cytometry analysis revealed that the third passage rADMSCs were CD 44-and CD90-posi-tive, but negative for hematopoietic cells surface marker CD 45.The growth curves of cells in the experimental and control groups were “S” shaped, showing a non-significant difference between the two groups (P>0.05).The oil red O staining and alizarin red staining results were positive at 2 weeks after adipogenic and osteogenic induction .The ALP activities of the two groups were increased with osteogenic induction time , with a non-significant difference (P>0.05).Conclusions Cryopreservation does not affect the growth and differentiation pluripotency of rADMSCs significantly .