Objective:To compare the clinical efficacy of navigation system and orthopedic robot-assisted nail placement in the treatment of lower cervical fracture and dislocation.Methods:A retrospective cohort study was conducted to analyze the clinical data of 49 patients with fracture and dislocation of the lower cervical spine who were admitted to Honghui Hospital, Xi′an Jiaotong University School of Medicine from May 2021 to October 2022, including 38 males and 11 females, aged 29-61 years [(39.3±7.3)years]. Injury segments involved C 3 in 12 patients, C 4 in 11, C 5 in 8, C 6 in 9 and C 7 in 9. Twenty-one patients were treated with S8 navigation system (navigation group, 84 screws), and 28 with TINAVI orthopedic robot (robot group, 112 screws). The two groups were compared in terms of the total surgical duration, single screw placement time, total screw placement time, distance between the screw and the anterior cortex, incision length, intraoperative radiation dose, intraoperative blood loss and length of hospital stay. The height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and American Spinal Injury Association (ASIA) grade were assessed before surgery and at 3 days after surgery. Visual analogue scale (VAS), Japanese Orthopedic Association (JOA) score and neck dysfunction index (NDI) before surgery, at 3 days, 3 months after surgery and at the last follow-up were compared. The accuracy of screw placement, intraoperative invasion rate of adjacent facet joints and rate of postoperative complications (infection, screw loosening, etc.) were evaluated. Results:All the patients were followed up for 12-16 months [(13.6±1.9)months]. In the navigation group, the total surgical duration, distance from the screw to the anterior cortex and the intraoperative radiation dose were (236.2±30.6)minutes, (2.0±0.2)mm and (374.3±90.3)mGy respectively, which were significantly shorter or less than those in the robot group [(278.4±20.7)minutes, (10.6±2.9)mm and (448.4±77.9)mGy] ( P<0.01). The single screw placement time, total screw placement time, incision length and intraoperative blood loss were (3.5±0.4)minutes, (23.9±0.5)minutes, (9.1±2.4)cm and (422.2±30.4)ml respectively, which were significantly longer or more than those in the robot group [(2.6±0.2)minutes, (17.9±0.7)minutes, (6.6±2.6)cm and (360.3±56.3)ml] ( P<0.01). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). No significant differences were observed in the height of the intervertebral space, Cobb angle, sliding distance between the vertebral bodies and ASIA grade between the two groups ( P>0.05). At 3 days after surgery, the height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and ASIA grade in both groups were significantly improved when compared with those before surgery ( P<0.05 or 0.01). There were no significant differences in VAS, JOA scores or NDI between the two groups before surgery, at 3 days, 3 months after surgery and at the last follow-up ( P>0.05). The VAS, JOA scores and NDI in both groups were gradually improved at 3 days, 3 months and at the last follow-up after surgery when compared with those before surgery ( P<0.05). There was no significant difference in the accuracy of screw placement of levels 0 and 0+1 between the two groups ( P>0.05). No significant difference in the intraoperative invasion rate of adjacent facet joints between the two groups was found ( P>0.05). There were no serious complications such as infection or screw loosening after surgery in both groups. Conclusions:For lower cervical fracture and dislocation, although there are more advantages in total surgical duration, screw holding force and radiation control regarding the navigation system, and more outstanding performance in screw placement efficiency, incision length and intraoperative blood loss regarding the orthopedic robot, both of them can effectively rebuild the cervical structure, improve neurological function, relieve postoperative pain, improve screw placement accuracy and reduce facet joint injury and serious complications. Selection of the best auxiliary screw placement system should comprehensively consider patients′ conditions and the experience of the surgical team.

AIM:To investigate the impact of core 1 β3-galactosyltransferase-specific molecular chaperone(COSMC)on the stem cell-like properties of gastric adenocarcinoma cells,and to elucidate its underlying mechanism.METHODS:GEPIA(Gene Expression Profiling Interactive Analysis),TIMER(Tumor IMmune Estimation Resource),Wei Sheng Xin platform,UALCAN(University of Alabama at Birmingham Cancer Data Analysis Portal)and UCSC(Uni-versity of California,Santa Cruz)Xena databases were employed to analyze COSMC expression levels across various carci-noma types.The COSMC expression in gastric cancer tissues and cell lines was evaluated using Western blot analysis.Transfection of small interfering RNA was used to knock down COSMC in MKN-45 cell line.In vitro experiments were con-ducted to explore the relationship between the COSMC expression and the stem cell-like properties of gastric cancer.The qPCR,sphere formation assay,soft agar colony formation assay and CCK-8 assay were used to evaluate the effect of COSMC on the stem cell-like properties of gastric cancer cells.Tn+and Tn-cells were isolated using Vicia villosa lectin(VVL)-conjugated immunomagnetic beads to investigate the influence of Tn structure on the stem cell-like characteristics of gastric cancer cells.Finally,the effect of COSMC knockdown on the mitogen-activated protein kinase(MAPK)signal-ing pathway was evaluated by Western blot analysis.RESULTS:(1)The COSMC exhibited differential expression across pancarcinoma,gastric cancer tissues and gastric cancer cell lines,with elevated expression levels in gastric cancer tissues and gastric cancer cell lines compared with normal tissues and gastric epithelial cell line.(2)Knockdown of COSMC sig-nificantly down-regulated the mRNA levels of stem cell markers NANOG,OCT-4 and CD44 in gastric cancer cells,re-duced the efficiency of soft agar colony formation and sphere formation,and increased the sensitivity of the cells to 5-fluo-rouracil(5-FU).(3)The efficiency of tumor sphere formation and soft agar colony formation in Tn-cells,and the resis-tance to 5-FU were significantly higher than those in Tn+cells.(4)Knockdown of COSMC decreased the protein levels of MAPK signaling pathway-related molecules,including c-Jun N-terminal kinase(JNK),p38 and phosphorylated extracel-lular signal-regulated kinase(p-ERK).CONCLUSION:The COSMC has the potential to enhance the stem cell-like properties of gastric cancer cells,which was likely mediated through the activation of the MAPK signaling pathway.

AIM:To investigate the impact of core 1 β3-galactosyltransferase-specific molecular chaperone(COSMC)on the stem cell-like properties of gastric adenocarcinoma cells,and to elucidate its underlying mechanism.METHODS:GEPIA(Gene Expression Profiling Interactive Analysis),TIMER(Tumor IMmune Estimation Resource),Wei Sheng Xin platform,UALCAN(University of Alabama at Birmingham Cancer Data Analysis Portal)and UCSC(Uni-versity of California,Santa Cruz)Xena databases were employed to analyze COSMC expression levels across various carci-noma types.The COSMC expression in gastric cancer tissues and cell lines was evaluated using Western blot analysis.Transfection of small interfering RNA was used to knock down COSMC in MKN-45 cell line.In vitro experiments were con-ducted to explore the relationship between the COSMC expression and the stem cell-like properties of gastric cancer.The qPCR,sphere formation assay,soft agar colony formation assay and CCK-8 assay were used to evaluate the effect of COSMC on the stem cell-like properties of gastric cancer cells.Tn+and Tn-cells were isolated using Vicia villosa lectin(VVL)-conjugated immunomagnetic beads to investigate the influence of Tn structure on the stem cell-like characteristics of gastric cancer cells.Finally,the effect of COSMC knockdown on the mitogen-activated protein kinase(MAPK)signal-ing pathway was evaluated by Western blot analysis.RESULTS:(1)The COSMC exhibited differential expression across pancarcinoma,gastric cancer tissues and gastric cancer cell lines,with elevated expression levels in gastric cancer tissues and gastric cancer cell lines compared with normal tissues and gastric epithelial cell line.(2)Knockdown of COSMC sig-nificantly down-regulated the mRNA levels of stem cell markers NANOG,OCT-4 and CD44 in gastric cancer cells,re-duced the efficiency of soft agar colony formation and sphere formation,and increased the sensitivity of the cells to 5-fluo-rouracil(5-FU).(3)The efficiency of tumor sphere formation and soft agar colony formation in Tn-cells,and the resis-tance to 5-FU were significantly higher than those in Tn+cells.(4)Knockdown of COSMC decreased the protein levels of MAPK signaling pathway-related molecules,including c-Jun N-terminal kinase(JNK),p38 and phosphorylated extracel-lular signal-regulated kinase(p-ERK).CONCLUSION:The COSMC has the potential to enhance the stem cell-like properties of gastric cancer cells,which was likely mediated through the activation of the MAPK signaling pathway.

Objective:To compare the clinical efficacy of navigation system and orthopedic robot-assisted nail placement in the treatment of lower cervical fracture and dislocation.Methods:A retrospective cohort study was conducted to analyze the clinical data of 49 patients with fracture and dislocation of the lower cervical spine who were admitted to Honghui Hospital, Xi′an Jiaotong University School of Medicine from May 2021 to October 2022, including 38 males and 11 females, aged 29-61 years [(39.3±7.3)years]. Injury segments involved C 3 in 12 patients, C 4 in 11, C 5 in 8, C 6 in 9 and C 7 in 9. Twenty-one patients were treated with S8 navigation system (navigation group, 84 screws), and 28 with TINAVI orthopedic robot (robot group, 112 screws). The two groups were compared in terms of the total surgical duration, single screw placement time, total screw placement time, distance between the screw and the anterior cortex, incision length, intraoperative radiation dose, intraoperative blood loss and length of hospital stay. The height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and American Spinal Injury Association (ASIA) grade were assessed before surgery and at 3 days after surgery. Visual analogue scale (VAS), Japanese Orthopedic Association (JOA) score and neck dysfunction index (NDI) before surgery, at 3 days, 3 months after surgery and at the last follow-up were compared. The accuracy of screw placement, intraoperative invasion rate of adjacent facet joints and rate of postoperative complications (infection, screw loosening, etc.) were evaluated. Results:All the patients were followed up for 12-16 months [(13.6±1.9)months]. In the navigation group, the total surgical duration, distance from the screw to the anterior cortex and the intraoperative radiation dose were (236.2±30.6)minutes, (2.0±0.2)mm and (374.3±90.3)mGy respectively, which were significantly shorter or less than those in the robot group [(278.4±20.7)minutes, (10.6±2.9)mm and (448.4±77.9)mGy] ( P<0.01). The single screw placement time, total screw placement time, incision length and intraoperative blood loss were (3.5±0.4)minutes, (23.9±0.5)minutes, (9.1±2.4)cm and (422.2±30.4)ml respectively, which were significantly longer or more than those in the robot group [(2.6±0.2)minutes, (17.9±0.7)minutes, (6.6±2.6)cm and (360.3±56.3)ml] ( P<0.01). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). No significant differences were observed in the height of the intervertebral space, Cobb angle, sliding distance between the vertebral bodies and ASIA grade between the two groups ( P>0.05). At 3 days after surgery, the height of intervertebral space, Cobb angle, sliding distance between vertebral bodies and ASIA grade in both groups were significantly improved when compared with those before surgery ( P<0.05 or 0.01). There were no significant differences in VAS, JOA scores or NDI between the two groups before surgery, at 3 days, 3 months after surgery and at the last follow-up ( P>0.05). The VAS, JOA scores and NDI in both groups were gradually improved at 3 days, 3 months and at the last follow-up after surgery when compared with those before surgery ( P<0.05). There was no significant difference in the accuracy of screw placement of levels 0 and 0+1 between the two groups ( P>0.05). No significant difference in the intraoperative invasion rate of adjacent facet joints between the two groups was found ( P>0.05). There were no serious complications such as infection or screw loosening after surgery in both groups. Conclusions:For lower cervical fracture and dislocation, although there are more advantages in total surgical duration, screw holding force and radiation control regarding the navigation system, and more outstanding performance in screw placement efficiency, incision length and intraoperative blood loss regarding the orthopedic robot, both of them can effectively rebuild the cervical structure, improve neurological function, relieve postoperative pain, improve screw placement accuracy and reduce facet joint injury and serious complications. Selection of the best auxiliary screw placement system should comprehensively consider patients′ conditions and the experience of the surgical team.

Objective:To compare the efficacy of percutaneous vertebroplasty (PVP) under enhanced regional and conventional anesthesia for multisegmental acute symptomatic osteoporotic thoracolumbar fractures (m-ASOTLF).Methods:A retrospective cohort study was conducted to analyze the data of 91 patients with m-ASOTLF who were admitted to Honghui Hospital of Xi′an Jiaotong University from January 2021 to December 2022, including 36 males and 55 females, aged 55-80 years [(67.4±7.3)years]. According to American Society of Anesthesiologists (ASA) classification system, 18 patients were classified as grade I, 52 grade II, and 21 grade III. Injured segments included T 6-T 10 in 23 patients, T 11-L 2 in 47 and L 3-L 5 in 21. All the patients were treated with PVP, among whom 45 were given enhanced regional anesthesia (enhanced anesthesia group) and 46 regional conventional anesthesia (conventional anesthesia group). The following indicators were compared between the two groups: the operation time, intraoperative bleeding, intraoperative heart rate, intraoperative mean arterial pressure (MAP), number of intraoperative fluoroscopies, and total amount of bone cement injected; the visual analogue scale (VAS) and Oswestry dysfunction index (ODI) before surgery, at 1 day, 1 month after surgery and at the last follow-up; the mini-mental state examination (MMSE) before surgery, at 1, 6, and 12 hours after surgery; the anterior vertebrae height (AVH), middle vertebrae height (MVH), and vertebral kyphosis angle (VKA) before and at 1 day after surgery; the incidence of complications such as bone cement leakage. Results:All the patients were followed up for 12-20 months [(15.8±2.6)months]. There were no significant differences between the two groups in the operation time, intraoperative bleeding, intraoperative heart rate, intraoperative MAP, number of intraoperative fluoroscopies or total amount of bone cement injected ( P>0.05). No significant differences were found between the two groups in VAS or ODI before surgery and at the last follow-up ( P>0.05). The VAS scores in the enhanced anesthesia group were (2.5±0.4)points and (1.8±0.3)points at 1 day and 1 month postoperatively respectively, which were both lower than (3.5±0.4)points and (2.0±0.5)points in the conventional anesthesia group ( P<0.01). The ODI values in the enhanced anesthesia group were 39.8±3.3 and 26.5±5.0 at 1 day and 1 month postoperatively respectively, which were both lower than 43.8±7.5 and 30.3±6.4 in the conventional anesthesia group ( P<0.01). The VAS and ODI at all postoperative time points decreased in both groups compared with those before surgery, with significant differences among those at all postoperative time points ( P<0.05). There was no significant difference between the two groups in the MMSE scores before, at 1, 6, and 12 hours after surgery ( P>0.05). The MMSE scores at 1 and 6 hours postoperatively were lower than that preoperatively in both groups ( P<0.05), and it was increased at 6 hours compared with that at 1 hour postoperatively ( P<0.05). There was no significant difference between the MMSE scores at 12 hours postoperatively and preoperatively in both groups ( P>0.05). The differences between the two groups in AVH, MVH, or VKA preoperatively were not statistically significant ( P>0.05). The AVH and MVH at 1 day postoperatively in the enhanced anesthesia group were (22.4±4.2)mm and (22.7±3.7)mm respectively, which were both higher than those in the conventional anesthesia group [(19.3±3.7)mm and (20.1±6.3)mm] ( P<0.05 or 0.01); the VKA at 1 day postoperatively in the enhanced anesthesia group was (13.9±3.7)°, which was lower than that in the conventional anesthesia group (15.8±4.1)° ( P<0.05). The AVH, MVH, and VKA in both groups were all improved at 1 day postoperatively compared with those preoperatively ( P<0.05). The incidence of bone cement leakage in the enhanced anesthesia group was 6.7% (3/45), which was lower than 21.7% (10/46) in the conventional anesthesia group ( P<0.05). Conclusion:Compared with conventional regional anesthesia, PVP under enhanced regional anesthesia for m-ASOTLF has more advantages in early postoperative pain relief, improvement of spinal function, restoration of vertebral height and reduction of bone cement leakage.

Primary central nervous system lymphoma (PCNSL) is a highly aggressive malignant lymphoma. As most chemotherapy drugs have difficulty in crossing the blood-brain barrier, PCNSL shows a difficulty in clinical treatment, a high recurrence rate and a poor prognosis. Early identification of relapsed patients and prompt initiation of salvage therapy play a critical role in the improvement of patients' prognosis. Brain biopsy is the gold standard to identify recurrence, while the risk of operation failure and complications is still high. Non-invasive imaging techniques are beneficial for early identification of recurrence in PCNSL and can provide an important basis for guiding relapsed patients to adjust treatment plans in time. However, there is no unified evaluation standard for imaging methods of monitoring the relapsed lesions of PCNSL. With the further research of the pathophysiological mechanism of PCNSL, biomarker detection has become a new method to identify recurrence and more clinical evidence is still needed in the future.

Intracranial germ cell tumors (iGCT) is a common cause of delayed puberty (DP).　A retrospective analysis was conducted on the clinical data of two patients with DP caused by iGCT. The disease characteristics of the two patients included DP, primary amenorrhea, growth retardation, short stature, subclinical hypothyroidism, etc. They were diagnosed as DP through imaging and related biochemical tests, and some sex hormone drugs were given on the basis of active treatment of the primary disease. Two patients had varying degrees of development in height, weight and secondary sexual characteristics, and further treatment condition is being tracking by us. Early identification and appropriate clinical intervention are of great significance to the reproductive endocrine function, bone health and long-term health such as terminal height of DP patients.

Intracranial germ cell tumors (iGCT) is a common cause of delayed puberty (DP).　A retrospective analysis was conducted on the clinical data of two patients with DP caused by iGCT. The disease characteristics of the two patients included DP, primary amenorrhea, growth retardation, short stature, subclinical hypothyroidism, etc. They were diagnosed as DP through imaging and related biochemical tests, and some sex hormone drugs were given on the basis of active treatment of the primary disease. Two patients had varying degrees of development in height, weight and secondary sexual characteristics, and further treatment condition is being tracking by us. Early identification and appropriate clinical intervention are of great significance to the reproductive endocrine function, bone health and long-term health such as terminal height of DP patients.

Objective:To compare the clinical efficacies of robot-assisted and free-hand long segment screw fixation combined with wedge osteotomy in the treatment of type IV chronic symptomatic osteoporotic thoracolumbar fractures (CSOVCFs).Methods:A retrospective cohort study was conducted to analyze the clinical data of 72 patients with type IV CSOVCFs who were admitted to Honghui Hospital of Xi′an Jiaotong University from May 2019 to December 2021, including 22 males and 46 females; aged 61-82 years [(71.2±12.3)years]. Fracture segments were located at T 11-T 12 in 37 patients and at L 1-L 2 in 31. A total of 32 patients were treated with robot-assisted long segment screw fixation combined with wedge osteotomy (robot group) and 36 with free-hand long segment screw fixation combined with wedge osteotomy (free-hand group). The operation time, intraoperative bleeding volume, dosage of radiation exposure, intraoperative needle adjustment, time of single pedicle screw placement and accuracy of pedicle screw placement were compared between the two groups. The kyphotic Cobb angle, sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar kyphosis (LL), visual analogue scale (VAS) and Oswestry disability index (ODI) were measured preoperatively, at 3 days postoperatively and at the last follow-up. The incidences of facet joint violation, deviation in guide needle placement, cerebrospinal leak and proximal junctional kyphosis (PJK) were observed. Results:All patients were followed up for 12-26 months [(18.2±5.1)months]. The operation time and time of single pedicle screw placement showed no significant differences between the two groups (all P>0.05). The intraoperative bleeding volume was (502.5±58.3)ml in the robot group, less than that in the free-hand group [(690.2±45.9)ml]. The dosage of radiation exposure was (32.6±10.8)μSv in the robot group, lower than that in the free-hand group [(48.6±15.2)μSv]. The intraoperative needle adjustment was (2.1±0.3)times in the robot group, higher than that in the free-hand group [(20.7±5.8)times], and the accuracy of pedicle screw placement was 99.7% in the robot group, less than that in the free-hand group (91.8%) (all P<0.01). Compared with pre-operation, the kyphotic Cobb angle, SVA, TK and LL were significantly improved in both groups at postoperative 3 days and at the last follow-up (all P<0.05). Compared with postoperative 3 days, the kyphotic Cobb angle, SVA and TK were increased at the last follow-up within the two groups, but with no significant differences (all P>0.05). Compared with postoperative 3 days, the LL was decreased within the two groups at the last follow-up, but with no significant differences (all P>0.05). The VAS and ODI in the two groups were significantly lower at postoperative 3 days and at the last follow-up when compared with those before operation (all P<0.05), and both values were significantly lower at the last follow-up than those at postoperative 3 days (all P<0.05). There were no significant differences in the VAS or ODI at all time points between the two groups (all P>0.05). The incidence of facet joint violation in the robot group was 1.6%, markedly lower than that in the free-hand group (9.6%) ( P<0.01). The incidences of deviation in guide needle placement, cerebrospinal leak and PJK showed no differences between the two groups (all P>0.05). Conclusion:For type IV CSOVCFs, the robot-assisted long segment screw fixation combined with wedge osteotomy can better reduce intraoperative blood loss, decrease radiation exposure, improve accuracy of pedicle screw placement, and reduce facet joint violation when compared with free-hand long segment screw fixation combined with wedge osteotomy.

Objective:To compare the clinical efficacies of O-arm combined with CT three-dimensional navigation system assisted screw placement versus manual screw placement in treating lower cervical fracture and dislocation.Methods:A retrospective cohort study was used to analyze the clinical data of 41 patients with lower cervical fracture and dislocation, who were treated in Honghui Hospital, Xi′an Jiaotong University from May 2021 to February 2022. The patients included 26 males and 15 females, aged 31.5-48.6 years [(41.5±15.0)years]. The injured segments were C 3 in 3 patients, C 4 in 12, C 5 in 13, C 6 in 10 and C 7 in 3. Nineteen patients were treated with cervical pedicle screws by O-shaped arm combined with CT three-dimensional navigation system (navigation group, 76 screws) and 22 by bare hands (traditional group, 88 screws). The total operation time, effective operation time, single nail placement time, single screw correction times, screw distance from anterior cortex, intraoperative blood loss, intraoperative fluoroscopic radiation dose, incision length and length of hospital stay were compared between the two groups, and the height of intervertebral space, Cobb angle, interbody slip distance and American Spinal injury Association (ASIA) grade were compared before operation and at 3 days after operation. Visual analogue score (VAS), Japanese Orthopedic Association (JOA) score, and neck dysfunction index (NDI) were evaluated before operation, at 3 days, 3 months after operation and at the last follow-up. Accuracy of screw placement and incidence of complications (adjacent facet joint invasion, infection, screw loosening) were detected as well. Results:All the patients were followed up for 11.1-13.9 months [(12.5±1.4)months]. The total operation time, intraoperative blood loss, intraoperative fluoroscopic radiation dose and incision length in the navigation group were more or longer than those in the traditional group (all P<0.05). The effective operation time, single nail placement time, single nail correction times and screw distance from anterior cortex in the navigation group were markedly less or smaller than those in the traditional group (all P<0.05). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). There were significant improvements in the height of intervertebral space, Cobb angle and interbody slip distance between the two groups at 3 days after operation (all P<0.05). There was no significant difference in the height of intervertebral space, Cobb angle, interbody slip distance or ASIA grade between the two groups before operation or at 3 days after operation (all P>0.05). Compared with pre-operation, the VAS, JOA score and NDI were significantly improved in both groups at 3 days, 3 months after operation and at the last follow-up (all P<0.05), with further improvement with time. There was no significant difference in VAS between the two groups before operation or at 3 months after operation (all P>0.05), but it was markedly lower in the navigation group compared with the traditional group at 3 days after operation and at the last follow-up (all P<0.05). There were no significant differences in JOA score or NDI between the two groups before operation or at 3 days and 3 months after operation (all P>0.05), but both were lower in the navigation group compared with the traditional group at the last follow-up (all P<0.05). The accuracies of placement of grade 0 and grade 0+1 screws were 92.0% (70/76) and 96.6% (73/76) in the navigation group, respectively, which were markedly higher than 88.7% (78/88) and 93.5% (82/88) in the traditional group (all P<0.05). The rates of adjacent facet joint invasion of A, B, and C degrees were 71.2% (54/76), 28.8% (22/76) and 0% (0/76) in the navigation group, respectively, while the invasion rates were 60.5% (53/88), 32.3% (28/88) and 7.3% (7/88) in the traditional group ( P<0.05). No screw loosening was noted in the navigation group, but the screw loosening rate was 9.1% (8/88) in the traditional group ( P<0.01). Conclusion:Compared with manual screw placement, O-arm combined with CT three-dimensional navigation system assisted screw placement for lower cervical fracture and dislocation has the advantages of shorter effective operation time, quicker screw placement, stronger screw holding force, better cervical stability, slighter postoperative pain, higher screw placement accuracy, and lower facet joint invasion and screw loosening rates.