Objectives:To explore the long-term follow-up prognosis and risk factors in patients with neuro-logical function deterioration after expansive open-door laminoplasty at early postoperative stage(within 3 months).Methods:A retrospective analysis was conducted on 17 patients who experienced neurological func-tion deterioration(the mJOA score decreased by ≥ 1 point at postoperative 3 months'follow-up compared with that before operation)at early stage after receiving laminoplasty with the preservation of unilateral muscle-lig-ament complex in our department between January 2006 and December 2012.The patients were divided into non-recovery group(n=5)and recovery group(n=12)based on whether the mJOA score of one patient recovered to one's preoperative level at postoperative 10-year follow-up.The baseline data,perioperative information,postoperative 3-month,1-year and 10-year mJOA score,neck disability index(NDI)score,and visual analog scale(VAS)score,as well as the imaging data[Cobb angle,range of motion(ROM)of the cervical spine,and sagittal vertical axis(SVA)of C2-C7]were collected and compared for regression analysis.The differences be-tween different mJOA categories involved between the two groups were also compared.Results:The proportion of patients with ossification of longitudinal ligament(OPLL)in the non-recovery group was significantly higher than that in the recovery group.There were no statistically significant differences between the two groups in baseline information such as age,gender,BMI,comorbidities,spinal cord T2 high singnal intensity and devel-opmental cervical canal stenosis,as well as perioperative information such as operative time,blood loss and the length of hospital stay(P＞0.05).One patient in the non-recovery group had experienced cerebrospinal fluid leakage and C5 nerve root palsy and 1 patient in the recovery group had experienced cerebrospinal fluid leakage,and the difference wasn't with statistical significance between the two groups.After neurological dete-rioration occurred within postoperative 3 months,imaging examinations were conducted on all the patients and found none insufficient decompression,therefore no secondary surgical treatment was performed.The preopera-tive mJOA scores of the non-recovery group and recovery group were 13.30±2.46 and 14.71±1.41,respective-ly,with no statistically significant difference between the two groups.After early postoperative neurological function deterioration,the mJOA score at 1-year follow-up in the recovery group significantly improved com-pared to that at 3-month follow-up,which wasn't significantly different from the preoperative level,and the mJOA score at 10-year follow-up was significantly higher than the values before surgery and at previous fol-low-up visits.However,in the non-recovery group,the 1-year and 10-year follow-up mJOA scores weren't statistically different from the value at 3-month follow-up.There was no statistically significant difference in VAS scores and NDI scores between the two groups before surgery and at each follow-up;The intragroup comparison of VAS scores and NDI scores in both groups showed no significant difference between different time points.In the recovery group,the Cobb angle increased at each follow-up compared to the preoperative value,and SVA increased significantly at the 10-year follow-up.In the non-recovery group,there was no statistically significant difference in Cobb angle and SVA at each follow-up compared with the preoperative values.The ROMs at postoperative follow-up visits of the recovery group decreased significantly compared to that of preoperation,while no such difference was found in the non-recovery group.In addition,there were no significant differences in Cobb angle,ROM,and SVA between the two groups at preoperation and each follow-up.It was found that the patients in the non-recovery group were more likely to have the sensory function of lower extremity affected in neurological deterioration at postoperative early stage.The logistic re-gression results suggested that OPLL before operation was a risk factor for early postoperative neurological de-terioration that was hard to recovery at 10 years of follow-up.Conclusions:The patients with cervical OPLL before operation who suffer from early postoperative neurological deterioration after laminoplasty tend to be more difficult to recover in the long-term follow-up.

Objectives:To investigate the relationship between serum miR-550a-5p levels and spinal metas-tasis in patients with non-small cell lung cancer(NSCLC).Methods:The clinical data of 175 patients with NSCLC who received treatment in the Affiliated Hospital of Chengde Medical College between May 2021 and May 2023 were retrospectively analyzed.According to the results of whole body bone imaging,70 patients with spinal metastasis were enrolled into the metastasis group,and 104 patients without spinal metastasis were enrolled into the none-metastasis group.There were no statistically significant differences in gender,age,smoking,hypertension,thrombosis,and tumor location between the two groups(P＞0.05).The pathological type,clinical stage,lymph node metastasis,and tumor diameter of the patients were collected and compared between the two groups.qRT-PCR was used to detect the expression level of serum miR-550a-5p,enzyme-linked immunosorbent assay was used to detect the serum tartrate-resistant acid phosphatase-5b(TRACP-5b)and type Ⅰ collagen cross-linked C-terminal peptide(ICTP)levels.The differences in serum levels of TRACP-5b,ICTP,and miR-550a-5p were compared between the two groups.The receiver operating characteristic(ROC)curve was adopted to evaluate the diagnostic value of miR-550a-5p,TRACP-5b,and ICTP alone and in combination for spinal metastasis in NSCLC patients.Results:Compared with the none-metastasis group,serum TRACP-5b,ICTP,and miR-550a-5p levels were significantly higher in patients in the metastasis group(P＜0.05).The miR-550a-5p level was significantly higher in patients with tumor diameter≥5cm,lung adenocarcinoma,stage Ⅲ-Ⅳ,and lymph node metastasis than in patients with tumor diameter＜5cm,squamous carcinoma,stage Ⅰ-Ⅱ,and no lymph node metastasis(P＜0.05).Elevated serum miR-550a-5p,lung adenocarcinoma,stage Ⅲ-Ⅳ,and lymph node metastasis were the independent risk factors for the development of spinal metastasis in NSCLC patients(P＜0.05).The AUC of miR-550a-5p for diagnosing spinal metastasis in NSCLC patients was 0.851,and the sensitivity and specificity were 74.29％and 85.58％,respectively,at the optimal cut-off value of 0.20.The diagnostic efficacy of serum miR-550a-5p for diagnosing spinal metastasis in NSCLC patients was significantly better than that of TRACP-5b(Z=2.309,P=0.023)and ICTP(Z=1.852,P=0.049).The AUC of miR-550a-5p,TRACP-5b,and ICTP combination for the diagnosis of spinal metastasis in NSCLC patients was 0.931,and the sensitivity and specificity were 88.57％and 87.50％,respectively.The diagnostic efficacy of the three-marker combination was significantly better than that of the two-marker combination of TRACP-5b and ICTP(Z=2.205,P=0.027).Conclusions:Elevated level of serum miR-550a-5p is associated with spinal metastasis,which can be used as a molecular marker for predicting spinal metastasis in NSCLC patients,moreover,its combination use with bone metabolism-related tumor markers,the ICTP and TRACP-5b,can improve diagnostic efficacy.

Objectives:To summarize the disease characteristics of thoracolumbar adhesive spinal arach-noiditis.Methods:The clinical data of 35 patients with thoracoland lumbar adhesive spinal arachnoiditis treated in our hospital from May 2012 to July 2023 were retrospectively analyzed,including 26 males and 9 females,aged 34 to 80 years(56.0±10.4 years).There were 17 cases secondary to thoracolumbar fracture,12 cases of lumbar disc herniation or combined with lumbar spinal stenosis,3 cases of thoracic spinal stenosis,and 3 cases of intradural tumor.14 cases were primarily characterized by persistent burning pain in the trunk or lower limbs,or accompanied by limb spasms.Another 17 cases mainly presented with numbness and weakness.Additionally,13 cases experienced urinary dysfunction,and 4 cases lost the ability to walk.Com-puted tomography myelography(CTM)and MRI were used to determine the location and imaging features of thoracolumbar adhesive spinal arachnoiditis.The treatment plans of patients were recorded,and the visual analogue scale(VAS)for lumbar and leg pain and Oswestry disability index(ODI)were observed before treat-ment,at 3 months after treatment and final follow-up.The McCormick grading was used to assess the recov-ery of patients who underwent surgery at the final follow-up.Results:The lesions were located in the tho-racic spinal cord in 11 cases,the conus medullaris in 7 cases,the cauda equina in 14 cases,and long seg-ments from the thoracic spinal cord to conus medullaris or cauda equina in 3 cases.11 patients received conservative treatment,and the VAS score was 7(7,8)and ODI was 54％(32％,64％).Only 3 patients showed mild alleviation of pain symptoms after conservative treatment,with a final follow-up VAS score of 7(6,8)and an ODI of 50％(32％,64％).24 patients underwent surgical treatment,and 9 of whom showed no significant improvement in symptoms at the final follow-up,with preoperative and final follow-up VAS scores of 8(8,9)and ODI of 72％(60％,85％),and McCormick grade Ⅲ;5 patients had a significant long-term im-provement in symptoms after operation,who could walk independently or with the aid of assistive devices and recovered to some extent in bowel and bladder functions,with preoperative VAS score of 7(6,8)and ODI of 58％(33％,68％)improving to 4(3,4)and 32％(19％,35％)respectively at final follow-up,and McCormick grade Ⅰ;3 patients recovered to grade Ⅰ postoperatively,and worsened to grade Ⅱ between 2 and 6 months;6 patients recovered to grade Ⅰ to Ⅱ postoperatively,with symptoms worsening to preoperative level(grade Ⅲ)between 2 weeks and 2 years;1 patient was implanted with electrical spinal cord stimulation de-vice,who was recovered in symptoms(grade Ⅱ).Conclusions:Conservative treatment for thoracolumbar adhesive spinal arachnoiditis is relatively limited in efficacy.While surgical treatment can achieve significant clinical improvement in some patients,its effects vary significantly among individuals.Some patients show no significant improvement in symptoms after surgery,and there are even cases where symptoms recur or worsen over time.

Objectives:To explore the CT classification and evaluation methods of thoracoabdominal folded deformity in ankylosing spondylitis(AS).Methods:A retrospective analysis was conducted on 31 patients with AS thoracolumbar kyphosis who underwent thoracolumbar CT examinations between July 2017 and January 2024.There were 28 males and 3 females,with an average age of 45.0±8.9 years.The thoracoabdominal folded angle(TAFA)and the distances between xiphoid process and the superior edge of the pubic symphysis(XP)were measured on the mid-sagittal plane of thoracolumbar CT.The global kyphosis(GK),thoracic kypho-sis(TK),and lumbar lordosis(LL)Cobb angle and sagittal vertical axis(SVA)were measured on the full-length lateral radiograph of the spine.According to the effect of sagittal lumbar physiological curvature on the change of abdominal volume,a CT classification of AS thoracoabdominal folded deformity was innovatively classified into three types,type Ⅰ when there was physiological lordosis in the lumbar spine,type Ⅱ when the physiological curvature of the lumbar spine became straight,and type Ⅲ when there was lumbar kyphosis deformity.According to TAFA,type Ⅲ patients were divided into two subtypes:TAFA＞90° was subtype A,and TAFA ≤90° was subtype B.Five trained spinal surgeons independently evaluated and classified the clini-cal data of patients(with a 10d interval),and used Kendall's W-test to analyze the consistency of multiple observation results.Using one-way analysis of variance to compare the differences in the above measurement parameters between different types.Results:Among the 31 patients,there were 5 cases of thoracoabdominal folded deformity type Ⅰ,8 cases of type Ⅱ,12 cases of type Ⅲ A,and 6 cases of type ⅢB.The Kendall's W consistency coefficient for inter-observer classification was 0.954(P＜0.001).The average GK,TK,LL,SV A,TAFA,and XP of patients were 83.7°±29.9°,48.7°±21.3°,-13.9°±25.3°,22.8±14.9cm,128.1°±50.5°,and 16.8±8.9cm,respectively;The Kendall's W consistency coefficients between the different groups'measurement values of TAFA and XP were 0.946(P＜0.001)and 0.979(P＜0.001),respectively;There were significant differ-ences in TAFA and XP pairwise comparisons between different subtypes(P＜0.001).Conclusions:CT imaging classification can objectively evaluate the thoracoabdominal folded deformity in AS,and the distance between the xiphoid process and pubic symphysis and the TAFA are important indicators for evaluating the thoracoab-dominal folded deformity in AS.

Objectives:This study aims to evaluate the safety and efficacy of minimally invasive small inci-sion decompression surgery for patients with thoracolumbar metastatic cancer.Methods:A retrospective analy-sis was conducted on 71 cases of spinal metastases who underwent posterior decompression surgery in our de-partment from June 2017 to March 2024.There were 55 males and 16 females with an average age of 63.9±1.2 years.Among them,24 patients underwent posterior minimally invasive small incision decompression surgery,and 47 patients underwent routine posterior decompression surgery.Independent sample t-test and chi square test were used to evaluate the differences between the two groups of patients in baseline data such as age,gender,primaiy tumor pathological type and blood supply,surgical site,and preoperative embolism,as well as the differences in total blood loss,surgical time,surgical complications,postoperative allogeneic blood transfusion volume,postoperative drainage volume and drainage tube retention time,and postoperative hospital-ization time.Results:There was no significant difference in baseline data between the two groups of patients(P＜0.001).The postoperative blood loss in the minimally invasive small incision group was significantly lower than that in the conventional surgery group(P=0.003).The postoperative blood transfusion(P=0.011),total drainage volume(P=0.000),drainage tube retention time(P=0.000),and postoperative hospital stay(P=0.000)were significantly reduced in the minimally invasive small incision group compared to the conventional surgery group.The decrease in ALB on the first day after surgery in the minimally invasive group was significantly improved compared to the conventional surgery group(P=0.040).There was no significant difference in the in-cidence of dural injury,postoperative pain,and functional improvement between the two groups of patients.Conclusions:Minimally invasive small incision decompression surgery can effectively reduce surgical blood loss and allogeneic blood transfusion in patients,shorten postoperative hospital stay,and improve surgical complications and postoperative function similar to conventional surgery.

Objectives:To observe the effect of teriparatide and elcatonin on the efficacy of endoscopic lum-bar interbody fusion(Endo-LIF)in patients with osteoporosis.Methods:A total of 60 patients diagnosed with lumbar spinal stenosis combined with osteoporosis undergone Endo-LIE via posterior transforaminal approach(Endo-P/TLIF)in Foshan Jianxiang Orthopedics Hospital between July 2021 and February 2023 were collect-ed.Among the patients,30 treated with vitamin D+calcium+elcatonin for 3 months after operation were included in the control group(6 males,24 females,aged 67.0±6.6 years;12 involved single segments,18 involved double segments);30 treated with teriparatide+elcatonin+vitamin 1)+calcium for 3 months after operation were included in the observation group(7 males,23 females,aged 66.0±5.9 years;10 involved single segments,20 involved double segments).There were no statistical differences in age,sex ratio,bone mineral density(BMD)before treatment and surgical segments between the two groups(P＞0.05).The visual analogue scale(VAS)score,Oswestry disability index(ODI),and systemic bone metabolism indexes[P 1NP,β-CTX,BGP,2,5(OH)VitD]were counted before and at 1 month and 3 months after treatment.The intervertebral body fusion at 3 months after treatment,and the T values of BMD before and at 6 months after treatment were also collected and evaluated.A t-test or chi-square test was applied to compare the differences between the two groups.Results:There were no statistical differences in VAS scores,ODIs,bone metabolism indexes,and T values of BMD between the two groups before treatment(P＞0.05).At 1 and 3 months after treatment,the VAS scores and ODIs were significantly reduced in both groups,with the decrease in the observation group more significantly than that in the control group at the same time point(P＜0.05).P1NP,β-CTX,BGP and 2,5(OH)VitD in the observation group were significantly higher at 1 and 3 months after treatment compared with before treatment(P＜0.05).BGP and 2,5(OH)VitD in the control group increased significantly at 3 months after treatment compared with before treatment(P＜0.05).P1NP,β-CTX and BGP were higher in the observation group than in the control group at 3 months after treatment(P＜0.05).There was no statistical difference in 2,5(OH)VitD at the same time point between the two groups(P＞0.05).The intervertebral fusion rate in the observation group was significantly higher than that of the control group at 3 months after treatment(96.66％vs 80.00％,P＜0.05).The T value of BMD in the observation group was significantly higher than in the control group at 6 months after treatment(-2.76±0.37 vs 3.06±0.42,P＜0.05).Conclusions:Teriparatide combined with elcatonin can improve the clinical symptoms,bone mineral density,and systemic bone metabolism index changes,and enhance early interbody fusion rate after Endo-P/TLIF in osteoporosis patients.

Objectives:To investigate the clinical efficacy of visual working channel assisted percutaneous transforaminal endoscopic discectomy(PTED)in treating lumbar disc herniation(LDH).Methods:The medical records of 141 LDH patients who underwent PTED between June 2022 and June 2023 were retrospectively analyzed.The patients were divided into two groups of the visual group consisting of 68 cases(38 males and 30 females,with an average age of 48.0±15.9 years),and the transparent visual working channel was applied in PTED;And the traditional group including 73 cases(46 males and 27 females,with an age of 47.6±16.9 years),and the traditional metal working channel was applied in PTED.There was no statistical difference in the general data(gender,age,etc)between the two groups(P＞0.05).The operative time,intraoperative blood loss,postoperative length of hospital stay,and complication occurrence were compared between the two groups.The degree of low back pain was assessed using the visual analogue scale(VAS)score for pain,and the lumbar spine function was assessed using the Oswestry disability index(ODI)before operation,at one week and,1,3,and 6 months after surgery,and final follow-up,respectively.The MacNab criteria were used to assess the clinical outcomes of patients at the final follow-up.Results:The operative time,intraoperative blood loss,and postoperative length of hospital stay in the visual group was all less than those in the traditional group(71.06±8.97min vs 75.16±9.47min,14.19±2.66mL vs 15.58±2.81mL,2.16±0.96d vs 2.54±1.23d),and the differences were statistically significant(P＜0.05).The VAS scores and ODI one week after surgery,1,3,and 6 months after surgery,and at the final follow-up were significantly improved compared with the preoperative values in both groups(P＜0.05).At the final follow-up,the VAS score and ODI in the visual group were significantly improved compared with those in the traditional group[1.18±0.39 vs 1.27±0.45,(3.97±1.67)％vs(4.54±1.55)％],and the differences were statistically significant(P＜0.05).According to the MacNab criteria at the final follow-up,53 cases in the visual group were excellent,12 cases were good,and 3 cases were possible,with an excellent and good rate of 95.6％;52 cases in the traditional group were excellent,15 cases were good,4 cases were possible,and 2 cases were poor,with an excellent and good rate of 91.8％(P＞0.05).No surgery-related complications occurred in the visual group and 4 cases of nerve root irritation signs and 2 cases of postoperative recurrence occurred in the traditional group;The complication rate of the traditional group was 8.2％,and the complication rate of the visual group was lower than that of the traditional group,and the difference was statistically significant(P＜0.05).Conclusions:The visual working channel assisted PTED has the advantages of short operative time,little intraoperative bleeding,fast postoperative recovery,and few complications in treating LDH.

Objectives:To investigate the pedicle screw placement accuracy of robot-assisted minimally inva-sive transforaminal lumbar interbody fusion(RA-MIS-TLIF)and analyze its learning curve.Methods:A retro-spective analysis was conducted on the clinical data of 160 patients with degenerative lumbar diseases treated at the Department of Orthopedics,Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hos-pital between January 2019 and June 2022.The patients were divided into a robot group(n=80)and a manual group(n=80)based on the surgical approach.Each group was further divided into four subgroups(1,2,3,4)of 20 patients each,arranged sequentially according to the order of surgery dates.The total operative time,blood loss,and planning and screw placement time of the two surgical methods were statistically analyzed.Preoper-ative,postoperative 1d,and six-month postoperative visual analogue scale(VAS)scores for pain and Oswestry disability index(ODI)were compared across the four subgroups.The trends in total operative time and blood loss with increasing surgery cases were analyzed using a logarithmic regression model.Screw placement clas-sification was evaluated using the Gertzbein-Robbins classification based on postoperative CT scans,and then the screw placement accuracy was calculated.Results:All the surgeries were successfully completed.In the robot group,the total operative time was 162.9±5.7min,blood loss was 91.4±9.5mL,and planning and screw placement time was 42.1±1.3min;In the manual group,the total operative time was 169.1±6.6min,blood loss was 101.0±9.2mL,and planning and screw placement time was 57.0±6.3min.A total of 320 screws were placed in each group,with accuracy rates of 97％(311/320)in the robot group and 92％(295/320)in the manual group.Neither group had grade C or D screws.The total operative time decreased with the increase in the number of surgeries in both groups.The robot group achieved relative stability between subgroups 2 and 3[y=-5.894×ln(x)+183.891,R2=0.576,P＜0.05],while the manual group achieved relative stability between subgroups 3 and 4[y=-4.424×ln(x)+184.221,R2=0.376,P＜0.05].The blood loss also decreased with the increase in the number of surgeries in both groups,the robot group achieved relative stability between subgroups 2 and 3[y=-9.480×ln(x)+125.361,R2=0.547,P＜0.05],and the manual group achieved relative stability also between subgroups 2 and 3[y=-3.868×ln(x)+114.183,R2=0.148,P＜0.05].Postoperative VAS scores in the robot group decreased from 6.9±1.1 preoperatively to 2.4±0.9 on postoperative 1d(P＜0.05)and to 1.1±0.4 at six months(P＜0.05).In the manual group,VAS scores decreased from 7.0±0.9 preoperatively to 2.4±0.9 on postoperative 1d(P＜0.05)and to 1.4±0.6 at six months(P＜0.05).ODI in the robot group decreased from(59.5±7.1)％preoperatively to(20.0±4.1)％on postoperative 1d(P＜0.05)and to(10.8±3.0)％at six months(P＜0.05).In the manual group,ODI scores decreased from(57.7±6.9)％preoperatively to(19.6±4.6)％on postoperative 1d(P＜0.05)and to(11.3±3.4)％at six months(P＜0.05).All the 160 patients completed follow-ups with no severe complications reported during the follow-up period.Conclusions:Comparing with traditional MIS-TLIF with manual pedicle screw placement,RA-MIS-TLIF has a higher accuracy of screw placement and a smoother learning curve,which stabilizes after approximately 20 cases.

Objectives:To observe the clinical efficacy of one-stage posterior debridement and iliac bone in-terbody fusion combined with vacuum sealing drainage(VSD)for wound closure and closed continuous douche(CCD)for the treatment of primary lumbar spine infection.Methods:A retrospective analysis was conducted on the case data of 18 patients with primary lumbar spine infection who underwent one-stage posterior de-bridement with iliac bone interbody grafting and VSD incision closure+CCD treatment at our hospital be-tween January 2016 and December 2021.There were 9 males and 9 females,aged 53.2±16.0 years(22-80 years).mNGS sequencing and pathogen culture were employed to identify infectious pathogens and formulate targeted antibiotic treatment plans.The levels of erythrocyte sedimentation rate(ESR)and C-reactive protein(CRP)were measured from preoperative 3d to postoperative 60d(every 3 days)to evaluate the infection con-trol status.Clinical function recovery was assessed using the Barthel index(BI)and JOA scores before surgery and at 3 months postoperatively,calculating the improvement rates(significant improvement defined as ≥60％).The Frankel classification was recorded before operation and at 3 months post-operation to evaluate spinal cord injury recovery.Postoperative follow-up CT scans were conducted to record the time to bone fusion.Results:The combined results of mNGS sequencing and pathogenic culture were positive in 17 cases(17/18),including 8 cases of Staphylococcus aureus,3 cases of Escherichia coli,2 cases of Pseudomonas aeruginosa,1 case each of methicillin-resistant Staphylococcus aureus,Staphylococcus epidermidis,Enterococcus faecium,and Brucella species was also noted,all of which received appropriate sequential therapy.All the cases were followed up postoperatively for 18.0±8.2 months(12-38 months).The average levels of CRP and ESR returned to the normal ranges on postoperative 42d and 45d respectively and sustained thereafter.The BI was 63.7±11.3 points before operation,which was 89.8±7.0 points at 3 months postoperatively,with 16 cases achieving significant improvement(88.9％);The JOA score was 14.2±3.4 points before operation,which was 25.7±3.1 points at 3 months postoperatively,with 16 cases achieving significant improvement(88.9％).At 3 months af-ter operation,2 patients with Frankel grade C improved to grade E,2 improved to grade D,and the remain-ing 14 patients with Frankel grade D all improved to grade E.The average time for bone graft fusion post-surgery was 6.0±1.5 months.Conclusions:One-stage posterior debridement,iliac bone interbody grafting,and VSD incision closure combined with CCD can achieve thorough debridement,effective infection control,and reliable bone graft fusion in treating primary lumbar spine infection,which can improve neurological function of the patients.

Objectives:To investigate the factors influencing intraoperative blood loss in spinal metastatic tu-mor surgery and provide scientific evidence for personalized surgical planning and blood loss control measures in clinical practice.Methods:We retrospectively analyzed the clinical data of 223 patients with spinal metastatic tumors treated at the Spinal Surgery Department of Beijing Shijitan Hospital Affiliated to Capital Medical University from January 2019 to September 2024.The surgical methods included vertebroplasty,tumor resection or partial resection,vertebral body reconstruction and internal fixation,and palliative surgery.Data collected included patient demographics(age,sex,BMI,etc.),tumor characteristics(primary tumor type,vertebral metastasis location and involvement area,number of extraspinal metastases,etc.),surgical factors(surgical ap-proach,robotic assistance,operative time,etc.),and intraoperative blood loss.Univariate regression analysis was conducted on each of the above indicators,and multivariate regression analysis was performed on the in-dicators with statistical significance to identify the influence of each factor on intraoperative blood loss.Re-sults:The intraoperative blood loss was 300mL(10,1000mL).Among the 223 patients,the proportion of metastasis in the thoracic and lumbar vertebrae was relatively high,and the blood loss was relatively signifi-cant in hypervascular tumors.The amount of blood loss in the tumor resection or partial resection and verte-bral body reconstruction and internal fixation groups was greater than that in the other two groups.Univariate analysis revealed that BMI(P＜0.001),primary tumor type(P＜0.001),vertebral metastasis location(P＜0.001),verte-bral involvement area(P＜0.001),number of extraspinal metastases(P=0.03),surgical approach(P＜0.001),robotic assistance(P＜0.001),and operative time(P＜0.001)were associated with intraoperative blood loss.Multivariate analysis identified BMI(P＜0.001),primary tumor type(P=0.02),vertebral metastasis location(P=0.02)and involve-ment area(P=0.004),surgical approach(P=0.04),and operative time(P＜0.001)as the independent predictors of intraoperative blood loss.Conclusions:Intraoperative blood loss in spinal metastatic tumor surgery is influ-enced by multiple factors,including BMI,primary tumor type,vertebral metastasis location and involvement area,surgical approach,and operative time.Sufficient preoperative evaluation shall be carried out,appropriate surgical approach shall be selected,and surgical techniques shall be improved to shorten operative time.