Objective To investigate the effect of bone morphogenetic protein 2 (BMP2)on ossification of the posterior longitudinal ligament (OPLL) and its relationship with transforming growth factor-3 (TGF-3)/Smad signaling pathway.Methods The expression vectors of wild type pcDNA3.1-BMP2 (WT),mutant pcDNA3.1-BMP2 (37G),mutant pcDNA3.1-BMP2 (190T) and mutant pcDNA3.1-BMP2 (37G/190T) were constructed and identified by agarose gel electrophoresis.The constructed vector was transfected into mouse embryonic fibroblasts C3H10T1/2 mediated by liposome to detect the expression of BMP2.Six groups were divided according to the transfection situation:(1) the non-transfection group;(2) empty vector pcDNA3.1 transfection group;(3) pcDNA3.1-bmp2 (WT)transfection group;(4) pcDNA3.1-bmp2 (37G) transfection group;(5) pcDNA3.1-bmp2 (190T)transfection group;(6) pcDNA3.1-bmp2 (37G/190T) transfection group.The experimental and control group were defined according to whether BMP2 polymorphism was included.Therefore,the nontransfection group and empty vector pcDNA3.1 transfection group were control groups,and the other groups were experimental groups.The expression of phosphorylated Smad1/5/8 and Smad4 in positive cell clones were detected by western blotting,and the alkaline phosphatase (ALP) was detected by quantitative detection kits.The protein expressions were compared among the experimental groups.Results Two fragments digested from pcDNA3.1-BMP2 represented 1.2 kb and 5.4 kb by agarose electrophoresis.The direct sequencing results were in accordance with target gene sequence.BMP2 gene was successfully transfected and stably expressed in C3H10T1/2 cells.Western blotting showed that the expression of phosphorylated Smad1/5/8 protein in the experimental groups was increased significantly after transfection,with significant difference between the experimental groups and the control groups (P ＜0.05),but without significant differences among the experimental groups (P ＞ 0.05).The expressions of Smad4 protein transfected by wild or mutation type pcDNA3.1-BMP2 were significantly higher than those in the control groups (P ＜ 0.05),and the expressions of Smad4 protein transfected by pcDNA3.1-BMP2(37G) and pcDNA3.1-BMP2 (37G/190T) were significantly higher than those in the other experimental groups (P＜0.05).The ALP activity results of experimental groups transfected by pcDNA3.1-BMP2 (37G) and pcDNA3.1-BMP2 (37 G/190T) were (30.56 ± 0.46) nmol · min-1 ·mg-1 and (29.62 ±0.68)nmol · min-1 · mg-1,with no significant difference between the two groups (P ＞0.05).However,there were significant differences between the two groups and other experimental groups (P ＜0.05).The Ser37Ala (T/G) polymorphism in exon 2 of BMP2 gene was positively correlated with ALP activity in stably transfected C3H10T1/2 cells.Conclusion The Ser37Ma (T/G) polymorphism in exon 2 of BMP2 gene promotes OPLL ossification through TGF-β/Smad signaling pathway,the possible mechanism for which is to up-regulate the protein expressions of Smad4 and ALP.

Objective To compare the Iso-C 3D navigation system versus the traditional X-ray fluoroscopy in minimally invasive surgery for Kümmell disease.Methods Included for the present retrospective study were 42 patients with Kümmell disease who had been treated by percutaneous kyphoplasty (PKP) or percutaneous vertebroplasty (PVP) at Department of Spine Surgery,Honghui Hospital from October 2016 to June 2018.They were 11 men and 31 women,aged from 43 to 72 years (average,57.4 years).The operation was aided by Iso-C 3D navigational system in 21 patients (observation group) and by X-ray fluoroscopy in the other 21 patients (control group).The 2 groups were compared before operation,one day and 6 months after operation in terms of visual analogue scale (VAS),Oswestry disability index (ODI),cobb angle and anterior vertebral height.Results The 2 groups were comparable because there were no significant differences between them in the preoperative general data (P ＞ 0.05).All the patients were followed up for an average of 9.6 months (from 6.0 to 18.5 months).At one day after operation for the observation andcontrol groups,the VAS scores (2.2 ±0.7 and 3.9 ± 1.5),ODI scores (15.6 ±2.8 and 26.2 ±6.9),cob angles (19.5° ± 1.7° and 20.8° ± 0.8°) and anterior vertebral heights (20.7 ± 1.4 and 18.7 ± 1.5 mm) were all significantly improved compared with those before operation (P ＜ 0.05).At 6 months after operation for the observation and control groups,the VAS scores (1.6±0.6 and 2.7±1.0),ODI (14.2±3.1 and 21.5 ±4.2),cob angles (18.6°± 1.8° and 19.0°± 1.7°) and anterior vertebral heights (19.9 ± 1.8 and 17.8 ± 1.6 mm) were not significantly different from those at one day after operation (P ＞ 0.05).The VAS,ODI,cobb angle and anterior vertebral height at one day after operation for the observation group were all significantly better than those for the control group (P ＜ 0.05).The VAS,ODI and anterior vertebral height at 6 months after operation for the observation group were significantly better than for the control group (P ＜ 0.05),but there was no significant difference between the 2 groups in the cobb angle (P ＞ 0.05).No complications were observed in the observation group but 6 cases in control group reported cement leakage.Conclusion In the PKP/PVP treatment of Kümmell disease,Iso-C 3D navigational system may be superior to traditional X-ray fluoroscopy in that it can lead to better recovery of anterior vertebral height,kyphosis correction,pain relief and quality of life.

Objective:To explore the efficacy of O-arm navigation system-assisted upper cervical pedicle screw internal fixation in the treatment of traumatic atlantoaxial instability.Methods:A retrospective cohort study was conducted to analyze the clinical data of 61 patients with atlantoaxial instability admitted to Affiliated Honghui Hospital of Xi′an Jiaotong University from January 2021 to June 2022, including 34 males and 27 females, aged 20-77 years [(50.2±13.1)years]. A total of 38 patients were treated with unarmed screw placement (unarmed group), and 23 with O-arm navigation system-assisted screw placement (navigation group). The unarmed group was divided into experienced group ( n=20) and unexperienced group ( n=18) based on the surgeons′ experience (whether they had 20 years or longer experience of spinal surgery and performed more than 100 atlantoaxial surgeries independently). The screw placement and surgical time of each group was recorded. The cervical CT scan was conducted at 7 days after surgery to evaluate the satisfaction rate of pedicle screw placement and cortical penetration rate according to Neo grading criteria. The cervical nerve function of the patients before, at 7 days after surgery and at the last follow-up was evaluated using the Japanese Orthopedic Association (JOA) score and the Neck Disability Index (NDI). The occurrence of complications was observed. Results:All patients were followed up for 9-25 months [(16.3±4.2)months]. There were no statistically significant differences in the screw placement and surgical time between the navigation group and the unarmed group (all P>0.05). The screw placement time of the navigation group was (41.0±7.8)minutes, longer than that of the experienced group [(23.6±6.8)minutes] ( P<0.01) and shorter than that of the unexperienced group [(50.1±10.1)minutes] ( P<0.05). The surgical time of the navigation group was (101.9±9.9)minutes, which was longer than that of the experienced group [(67.6±8.3)minutes] ( P<0.01) and shorter than that of the unexperienced group [(126.1±16.4)minutes] ( P<0.01). The satisfaction rate of pedicle screw placement and cortical penetration rate of the navigation group were 98.9% and 4.3%, respectively, which were better than those of the unarmed group (94.1% and 17.8%), the experienced group (96.2% and 13.8%), and the unexperienced group (91.7% and 22.2%) ( P<0.05 or 0.01). There was no statistically significant difference in JOA score or NDI before, at 7 days after surgery or at the last follow-up between the navigation group and the unarmed group, and no difference between the navigation group and the experienced group or the unexperienced group (all P>0.05). No complications such as spinal cord nervous or vascular injuries were observed during surgery in the navigation group or the unarmed group. Conclusions:Compared with the unarmed screw placement, O-arm navigation system-assisted upper cervical pedicle screw internal fixation shows no significant difference in screw placement time, surgical time, and postoperative neurological function status in the treatment of traumatic atlantoaxial instability, but has a higher accuracy in screw placement. Compared with the experienced surgeons′ unarmed screw placement, the technique also has higher screw placement accuracy but longer screw placement time and surgical time. Whereas in comparison with unexperienced surgeons′ unarmed screw placement, the technique can not only significantly improve its screw placement accuracy, while shortening screw placement time and surgical time so as to improve the surgical safety.

Objective:To investigate the perioperative risk factors of surgical site infection (SSI) of subaxial cervical spine injury after anterior surgery and provide a basis for the development of nursing measures.Methods:A retrospective case-control study was conducted to analyze the clinical data of 754 patients with subaxial cervical spine injury who underwent anterior surgery from January 2014 to January 2018, including 511 males and 243 females, aged 44-61 years [(50.2±5.1)years]. The fracture segment was C 3 in 60 patients, C 4 in 159, C 5 in 197, C 6 in 236 patients, and C 7 in 102. The patients were divided into two groups according to SSI occurrence. There were 28 patients in infected group and 726 patients in non-infected group. Data of the two groups were recorded, such as demographic data, American Spinal Injury Association (ASIA) scale, comorbidity, time interval from skin preparation to operation, preoperative urinary catheterization or not, consecutive operation or not, total number of staff involved in the operation, layer flow level of operating room, operating room temperature, relative humidity, operation duration, intern nurse involved in the operation or not and surgical methods. Univariate analysis was used to screen the indicators with statistically significant differences between the two groups. Multivariate Logistic regression analysis was further used to identify the risk factors of SSI. Results:The occurrence rate of SSI was 3.71% (28/754). The univariate analysis showed that there were significant differences between the two groups in ASIA scale, diabetes, dietary nursing, time interval from skin preparation to operation, preoperative urinary catheterization, consecutive operation, total number of staff involved in the operation, layer flow level of operating room and operation duration( P<0.01). The multivariate Logistic regression analysis showed that the ASIA scale (grade A: OR= 84.421, grade B: OR=27.200, P<0.01), diabetes ( OR=3.234, P<0.05), without diet nursing ( OR=2.375, P<0.05), time interval from skin preparation to operation ≥ 6 h ( OR=2.542, P<0.05), preoperative urinary catheterization ( OR=4.085, P<0.01), consecutive operation ( OR=2.894, P<0.05), total number of staff in the operating room ≥ 8 ( OR=3.137, P<0.01), layer flow level of operating room is grade 10, 000 or above ( OR=5.380, P<0.01) and operation duration≥ 3 h ( OR=2.405, P<0.05) were positively correlated with perioperative SSI. Conclusions:The factors associated with SSI of subaxial cervical spine injury after anterior surgery are the ASIA scale (grade A and B), diabetes, without diet nursing, time interval from skin preparation to operation ≥ 6 h, preoperative urinary catheterization, consecutive operation, total number of staff in the operating room ≥ 8, layer flow level of operating room (grade 10, 000 or above) and operation duration ≥3 h. For patients with subaxial cervical spine injury, attention should be paid to diet care, blood glucose monitoring should be strengthened, and operating room management should be optimized.