Objective To compare the clinical efficacies among three surgical methods in the treatment of stage Ⅲ Kümmell's disease without neurological symptoms.Methods A total of 71 patients with stage Ⅲ Kümmell's disease without neurological symptoms admitted and treated in the orthopedics department of Af-filiated Yueyang Hospital of Hunan Normal University from September 2019 to April 2022 were selected and divided into three groups:29 cases in the percutaneous vertebroplasty (PVP) group (group A),19 cases in the percutaneous pedicle screw+lesioned vertebral PVP group (group B) and 21 cases in the percutaneous bone cement screw combined with lesioned vertebral PVP group (group C) according to the operation methods.The imaging,perioperative and follow-up indexes were compared among the three groups.Results All patients successfully completed the operation,no serious complications occurred after operation,and the follow-up time was more than 1 year.The sagittal position index (SI value) in the affected vertebra,visual analogue scale (VAS) score and Oswestry Disability Index (ODI) score at each time point (postoperative 1,3 months,1 year) after surgery in the group A were improved compared with before operation (P<0.05).The affected vertebra SI value,kyphosis Cobb angle,spinal canal stenosis rate,VAS score and ODI score at postoperative time points in the group B and C were improved compared with before operation (P<0.05).The affected ver-tebra SI value,kyphosis Cobb angle,spinal canal stenosis rate and ODI score at postoperative time points in the group B and C all were superior to those in the group A (P<0.05),while the affected vertebra SI value,kyphosis Cobb angle and spinal canal stenosis rate in postoperative 1 year in the group C were superior to those in the group B (P<0.05).The operative time,intraoperative bleeding volume,postoperative hospitaliza-tion duration and affected vertebral cement injection volume in the group A were significantly less than those in the group B and C (P<0.05).The operation time in the group B was less than that in the group C (P<0.05).Conclusion The three surgical methods for the treatment of stage Ⅲ Kümmell's disease without neu-rological symptoms all could relieve the symptoms and restore the function.The two surgical methods of pedi-cle screw reduction could more effectively restore the height of the affected vertebra,correct kyphosis malfor-mation and improve spinal stenosis than PVP alone.The pedicle screw has more advantages in maintaining mechanical support and stability after bone cement reinforcement.

Objechves:To establish an X-ray induced senescence model of rat intervertebral disc nucleus pulposus cells in vitro and to evaluate it.Methods:12 clean-grade mature SD rats were selected to take the lumbar intervertebral disc nucleus pulposus for cell culture in vitro,and the cultured nucleus pulposus cells were randomly divided into 0 Gy group(Control group),5Gy group,10Gy group and 15Gy group on the basis of different X-ray doses of irridiation.Cell morphology observation,SA-β-Gal staining,cell counting kit-8(CCK-8),flow cytometry(FCM),polymerase chain reaction(PCR),immunofluorescence(IF)technique,Western blot(WB)and 1,9-dimethyl-methylene blue(DMMB)colorimetric method were used to observe and compare the senescence and proliferation of different groups of nucleus pulposum cells.The expression of age-related genes,proteins and related factors were detected.Results:The nucleus pulposus cells gradually showed typi-cal characteristics of senescence in morphology with the increase of X-ray radiation dose,and the degree of aging was positively correlated with radiation dose.SA-β-Gal assay showed that the positive percentages of nucleus pulposus cells in 0Gy,5Gy,10Gy and 15Gy groups were 15％,41％,88％and 77％,respectively.CCK-8 experiment showed on the 5th day,the proliferation of nucleus pulposus cells in the 10Gy group re-sumed,while that in the 15Gy group still showed no proliferation.FCM confirmed that the cells were still active,and when the radiation dose was increased to 20Gy,the early apoptosis rate of nucleus pulposus cells increased sharply.Both IF and PCR showed that the expression of aging genes p16 and p21 increased with the increase of radiation dose,and the expression of aggrecan fragmentation was also increased in WB assay.The above experimental results suggested that 15Gy was the appropriate radiation dose.When the 15Gy group was compared with the control group again,CCK-8 showed no proliferation of nucleus pulposus cells in the 15Gy group on day 9,and the PCR showed significantly higher expression of aggrecan fragmentation in the 15Gy group than the control group(P＜0.05).The expression of MMP-1,MMP-3 and inflammatory factors IL-6 and IL-8 in PCR and IF were also significantly higher in 15Gy group than in the control group(P＜0.05).Conclusions:X-ray can induce senescence of the rat nucleus pulposus cells cultured in vitro,and the senescence degree of nucleus pulposus cells receiving 15Gy radiation is obvious and stable,which can be used as an ideal model of nucleus pulposus cell senescence.