This case report describes a 68-year-old male patient diagnosed with primary hepatocellular carcinoma (HCC). After receiving Yttrium-90 microsphere selective internal radiation therapy (⁹⁰Y-SIRT), the tumor significantly reduced in size, and tumor markers alpha fetoprotein (AFP) and abnormal prothrombin (PIVKA-Ⅱ) decreased. Postoperative pathological results showed minimal residual tumor cells, indicating that ⁹⁰Y-SIRT has good efficacy and safety in downstaging and conversion of HCC, thereby facilitating subsequent surgical resection.

Objective:To optimize the image quality of PET/CT following 90Y-selective internal radiation therapy ( 90Y-SIRT) using block-sequential regularized expectation maximization (BSREM) reconstruction algorithm, and to evaluate its impact of different β values on image quality and quantitative analysis. Methods:A retrospective study was conducted on 8 male patients with hepatic tumors (age: 62(52, 71) years) treated at Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine Tsinghua University, between June 2024 and January 2025. All patients were treated with 90Y resin microspheres (2.6(0.9, 3.6)GBq) and underwent post-treatment 90Y PET/CT liver imaging. Imaging data were reconstructed using BSREM with different noise penalty weighting factors ( β values: 0, 300, 1000, 1500, 2500, 3500, 4000, 6000, 8000, 10000). Visual assessment was independently performed by two nuclear medicine physicians, using a 4-point scale (1=worst, 4=best). The mean score was considered as the final score. The consistency of the 2 reviewers was calculated and analyzed by Kappa test. Visual scores of different β value groups were compared by Friedman test. The β value demonstrating highest mean score and optimal consistency was selected as the optimal. Quantitative analysis was performed using MIM software to calculate the maximum absorbed dose ( Dmax) and the mean absorbed dose ( Dmean) for tumor, normal liver, and whole liver regions, and the CV was used to evaluate the impact of β values. Results:The visual assessment consistency of reviewers in 3 β value groups (0, 3500, 6000) were the highest (7/8) (all kappa=0.88, all P<0.05). Visual scores of the 10 β value groups were significantly different ( χ2=28.74, P<0.001), and the visual scores of 2 β value groups (3500, 4000) were the highest, both of which were 4.0(4.0, 4.0). Overall, visual assessment identified β=3500 as the optimal. Quantitative analysis revealed that, (1) Dmax in all regions (tumor, normal liver, whole liver) decreased with the increasing β values, stabilizing when β>1000 ( CV 56%-67%); (2) Dmean remained stable across different β values ( CV 0.04%-5.00%). Conclusions:In BSREM reconstruction, β=3500 is the optimal parameter for improving 90Y-PET image quality. β values significantly affect Dmax (stabilizing at β > 1000), but have no significant impact on Dmean, suggesting that reconstruction parameters primarily influence dose distribution morphology rather than average dose assessments.

Objective:To compare the efficacy of laminoplasty via the intermuscular approach or posterior midline approach for treating spinal cord injury without radiographic abnormality (SCIWORA).Methods:A multi-center retrospective cohort study was conducted to analyze the clinical data of 135 patients with SCIWORA admitted to Honghui Hospital Affiliated to Xi'an Jiaotong University School of Medicine, Xi'an No.5 Hospital, Henan Provincial People's Hospital, Zhengzhou Orthopedic Hospital, Xuanwu Hospital of Capital Medical University from February 2021 to June 2023, including 75 males and 60 females, aged 35-78 years [(55.3±8.1)years]. The injury segments involved C 3-C 6. All the patients underwent posterior cervical open-door laminoplasty, among whom 70 patients were treated via the intermuscular approach (intermuscular group) and 65 via the posterior midline approach (posterior midline group). The operation duration, intraoperative blood loss, postoperative drainage volume, and length of hospital stay were recorded. The visual analogue scale (VAS) score, Japanese Orthopedic Association (JOA) score, neck disability index (NDI), Barthel index, cervical Cobb angle, and cervical range of motion (ROM) were measured preoperatively, at 3, 6, 12 months postoperatively and at the final follow-up. The American Spinal Injury Association (ASIA) scale was evaluated preoperatively, at 3, 12 months postoperatively and at the final follow-up. The postoperative complication rate was recorded as well. Results:All the patients were followed up for 15-19 months [(16.3±1.6)months]. The operation duration, intraoperative blood loss, postoperative drainage and length of hospital stay were (125.0±23.0)minutes, (210.4±34.8)ml, and (165.3±23.7)ml, and (5.3±0.1)days in the intermuscular group, which were significantly shorter or less than (168.0±27.6)minutes, (260.2±45.3)ml, (196.4±31.6)ml, and (6.4±0.2)days in the posterior midline group ( P<0.01). The preoperative VAS score, JOA score, NDI and Barthel index showed no significant differences between the two groups ( P>0.05). The VAS score and JOA score also showed no significant differences between the two groups at 3, 6, 12 months postoperatively or at the final follow-up ( P>0.05). The NDI and Barthel index also showed no significant differences between the two groups at 3 months postoperatively ( P>0.05). At 6, 12 months postoperatively and at the final follow-up, the NDI were (15.4±2.5)points, (11.8±2.1)points and (8.6±1.5)points in the intermuscular group, significantly lower than (19.1±3.4)points, (14.3±2.4)points and (11.9±1.4)points in the posterior midline group ( P<0.01). At 6, 12 months postoperatively and at the final follow-up, the Barthel index were (71.4±6.2)points, (83.4±5.8)points and (89.2±7.1)points in the intermuscular group, significantly higher than (59.6±4.7)points, (74.2±3.9)points and (78.8±6.2)points in the posterior midline group ( P<0.01). Both groups showed significant improvements in VAS score, JOA score, NDI and Barthel index at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P<0.05). Among them, the VAS score, NDI and Barthel index were further improved over time ( P<0.05). Simultaneously, the JOA score was significantly improved at 6, 12 months postoperatively and at the last follow-up when compared to that at 3 months postoperatively ( P<0.05), with no significant difference at later time points between the two groups ( P>0.05). The preoperative cervical Cobb angle and ROM showed no significant differences between the two groups ( P>0.05). There was no significant difference in the Cobb angle between the two groups at 3, 6 or 12 months postoperatively ( P>0.05), while it was (13.6±2.4)° in the intermuscular group at the final follow-up, significantly larger than (10.4±2.8)° in the posterior midline group ( P<0.01). At 3, 6, 12 months postoperatively and at the final follow-up, the cervical ROM were (34.1±6.4)°, (32.6±7.3)°, (31.8±9.1)° and (29.6±8.7)° in the intermuscular group, significantly larger than (23.7±8.3)°, (22.3±7.8)°, (22.5±8.1)° and (20.6±9.3)° in the posterior midline group ( P<0.01). In the intermuscular group, the cervical Cobb angle showed no significant changes at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P>0.05). In the posterior midline group, the Cobb angles were significantly reduced at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P<0.05), showing significant decrease at 12 months postoperatively and at the final follow-up from those at 3, 6 months postoperatively ( P<0.05), no significant difference at 6 months postoperatively from that at 3 months postoperatively ( P>0.05), and significant decrease at the final follow-up from that at 12 months postoperatively ( P>0.05). In the intermuscular group, the cervical ROM were significantly improved at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively and showed further improvement over time ( P<0.05). In the posterior midline group, the cervical ROM were significantly improved at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P<0.05), showing significant decreases at 6, 12 months postoperatively and at the final follow-up from that at 3 months postoperatively ( P<0.05), significant decreases at the final follow-up from those at 6, 12 months postoperatively ( P<0.05), and no significant difference at 12 months postoperatively from that at 6 months postoperatively ( P>0.05). The ASIA grades showed no significant difference between the two groups preoperatively, at 3, 12 months postoperatively and at the final follow-up ( P>0.05) , but were gradually improved over time in both groups ( P<0.05). The postoperative complication rate was 9%(6/70) in the intermuscular group, significantly lower than 48%(31/65) in the posterior midline group ( P<0.01). Conclusion:Compared to the posterior midline approach, the intermuscular approach for laminoplasty in patients with SCIWORA possesses advantages, including shorter operative time and length of hospital stay, reduced intraoperative blood loss and postoperative drainage, less postoperative neck disability, higher daily life quality, better long-term preservation of cervical lordosis and motion, and a lower complication rate.

Objective:To assess the effects of probiotic supplementation following bariatric surgery on weight loss outcomes, glycemic and lipid metabolism profiles, and nutritional status.Methods:Searches were conducted across China National Knowledge Infrastructure (CNKI), WanFang, VIP, Web of Science, and PubMed using Chinese or English search words including probiotics, morbid obesity, severe obesity, bariatric surgery, sleeve gastrectomy, Roux-en-Y gastric bypass, SG, and RYGB up to May 31, 2024. Meta-analysis was performed using Review Manager 5.3. Study quality was evaluated using Cochrane risk of bias tool.Results:In the 12 randomized controlled trials (RCTs) containing 663 severely obese patients who underwent bariatric surgery, 329 were in the probiotic group (receiving probiotic supplementation following bariatric surgery) and 334 in the control group (using placebo). Compared with the control group, the probiotic group had significantly lower fasting blood glucose ( WMD=-4.42 mg/dL, 95% CI: -7.71–-1.13, P=0.009) and triglyceride ( WMD=-18.75 mg/dL, 95% CI: -35.83–-1.67, P=0.03) and significantly increased vitamin B 12 ( SMD=0.52, 95% CI: 0.02–1.02, P=0.04). However, the two groups showed no significant differences in body mass index, waist circumference, weight, % excess weight loss, hemoglobin A1c, insulin, homeostasis model assessment of insulin resistance, total cholesterol, low-density lipoprotein, high-density lipoprotein, or vitamin D levels (all P>0.05). Conclusion:Supplementing probiotics after bariatric surgery can improve glucose and lipid metabolism and increase vitamin B 12 absorption, whereas its potential effect on weight loss remains unclear.

Objective:To assess the effects of probiotic supplementation following bariatric surgery on weight loss outcomes, glycemic and lipid metabolism profiles, and nutritional status.Methods:Searches were conducted across China National Knowledge Infrastructure (CNKI), WanFang, VIP, Web of Science, and PubMed using Chinese or English search words including probiotics, morbid obesity, severe obesity, bariatric surgery, sleeve gastrectomy, Roux-en-Y gastric bypass, SG, and RYGB up to May 31, 2024. Meta-analysis was performed using Review Manager 5.3. Study quality was evaluated using Cochrane risk of bias tool.Results:In the 12 randomized controlled trials (RCTs) containing 663 severely obese patients who underwent bariatric surgery, 329 were in the probiotic group (receiving probiotic supplementation following bariatric surgery) and 334 in the control group (using placebo). Compared with the control group, the probiotic group had significantly lower fasting blood glucose ( WMD=-4.42 mg/dL, 95% CI: -7.71–-1.13, P=0.009) and triglyceride ( WMD=-18.75 mg/dL, 95% CI: -35.83–-1.67, P=0.03) and significantly increased vitamin B 12 ( SMD=0.52, 95% CI: 0.02–1.02, P=0.04). However, the two groups showed no significant differences in body mass index, waist circumference, weight, % excess weight loss, hemoglobin A1c, insulin, homeostasis model assessment of insulin resistance, total cholesterol, low-density lipoprotein, high-density lipoprotein, or vitamin D levels (all P>0.05). Conclusion:Supplementing probiotics after bariatric surgery can improve glucose and lipid metabolism and increase vitamin B 12 absorption, whereas its potential effect on weight loss remains unclear.

Objective:To optimize the image quality of PET/CT following 90Y-selective internal radiation therapy ( 90Y-SIRT) using block-sequential regularized expectation maximization (BSREM) reconstruction algorithm, and to evaluate its impact of different β values on image quality and quantitative analysis. Methods:A retrospective study was conducted on 8 male patients with hepatic tumors (age: 62(52, 71) years) treated at Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine Tsinghua University, between June 2024 and January 2025. All patients were treated with 90Y resin microspheres (2.6(0.9, 3.6)GBq) and underwent post-treatment 90Y PET/CT liver imaging. Imaging data were reconstructed using BSREM with different noise penalty weighting factors ( β values: 0, 300, 1000, 1500, 2500, 3500, 4000, 6000, 8000, 10000). Visual assessment was independently performed by two nuclear medicine physicians, using a 4-point scale (1=worst, 4=best). The mean score was considered as the final score. The consistency of the 2 reviewers was calculated and analyzed by Kappa test. Visual scores of different β value groups were compared by Friedman test. The β value demonstrating highest mean score and optimal consistency was selected as the optimal. Quantitative analysis was performed using MIM software to calculate the maximum absorbed dose ( Dmax) and the mean absorbed dose ( Dmean) for tumor, normal liver, and whole liver regions, and the CV was used to evaluate the impact of β values. Results:The visual assessment consistency of reviewers in 3 β value groups (0, 3500, 6000) were the highest (7/8) (all kappa=0.88, all P<0.05). Visual scores of the 10 β value groups were significantly different ( χ2=28.74, P<0.001), and the visual scores of 2 β value groups (3500, 4000) were the highest, both of which were 4.0(4.0, 4.0). Overall, visual assessment identified β=3500 as the optimal. Quantitative analysis revealed that, (1) Dmax in all regions (tumor, normal liver, whole liver) decreased with the increasing β values, stabilizing when β>1000 ( CV 56%-67%); (2) Dmean remained stable across different β values ( CV 0.04%-5.00%). Conclusions:In BSREM reconstruction, β=3500 is the optimal parameter for improving 90Y-PET image quality. β values significantly affect Dmax (stabilizing at β > 1000), but have no significant impact on Dmean, suggesting that reconstruction parameters primarily influence dose distribution morphology rather than average dose assessments.

Objective:To compare the efficacy of laminoplasty via the intermuscular approach or posterior midline approach for treating spinal cord injury without radiographic abnormality (SCIWORA).Methods:A multi-center retrospective cohort study was conducted to analyze the clinical data of 135 patients with SCIWORA admitted to Honghui Hospital Affiliated to Xi'an Jiaotong University School of Medicine, Xi'an No.5 Hospital, Henan Provincial People's Hospital, Zhengzhou Orthopedic Hospital, Xuanwu Hospital of Capital Medical University from February 2021 to June 2023, including 75 males and 60 females, aged 35-78 years [(55.3±8.1)years]. The injury segments involved C 3-C 6. All the patients underwent posterior cervical open-door laminoplasty, among whom 70 patients were treated via the intermuscular approach (intermuscular group) and 65 via the posterior midline approach (posterior midline group). The operation duration, intraoperative blood loss, postoperative drainage volume, and length of hospital stay were recorded. The visual analogue scale (VAS) score, Japanese Orthopedic Association (JOA) score, neck disability index (NDI), Barthel index, cervical Cobb angle, and cervical range of motion (ROM) were measured preoperatively, at 3, 6, 12 months postoperatively and at the final follow-up. The American Spinal Injury Association (ASIA) scale was evaluated preoperatively, at 3, 12 months postoperatively and at the final follow-up. The postoperative complication rate was recorded as well. Results:All the patients were followed up for 15-19 months [(16.3±1.6)months]. The operation duration, intraoperative blood loss, postoperative drainage and length of hospital stay were (125.0±23.0)minutes, (210.4±34.8)ml, and (165.3±23.7)ml, and (5.3±0.1)days in the intermuscular group, which were significantly shorter or less than (168.0±27.6)minutes, (260.2±45.3)ml, (196.4±31.6)ml, and (6.4±0.2)days in the posterior midline group ( P<0.01). The preoperative VAS score, JOA score, NDI and Barthel index showed no significant differences between the two groups ( P>0.05). The VAS score and JOA score also showed no significant differences between the two groups at 3, 6, 12 months postoperatively or at the final follow-up ( P>0.05). The NDI and Barthel index also showed no significant differences between the two groups at 3 months postoperatively ( P>0.05). At 6, 12 months postoperatively and at the final follow-up, the NDI were (15.4±2.5)points, (11.8±2.1)points and (8.6±1.5)points in the intermuscular group, significantly lower than (19.1±3.4)points, (14.3±2.4)points and (11.9±1.4)points in the posterior midline group ( P<0.01). At 6, 12 months postoperatively and at the final follow-up, the Barthel index were (71.4±6.2)points, (83.4±5.8)points and (89.2±7.1)points in the intermuscular group, significantly higher than (59.6±4.7)points, (74.2±3.9)points and (78.8±6.2)points in the posterior midline group ( P<0.01). Both groups showed significant improvements in VAS score, JOA score, NDI and Barthel index at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P<0.05). Among them, the VAS score, NDI and Barthel index were further improved over time ( P<0.05). Simultaneously, the JOA score was significantly improved at 6, 12 months postoperatively and at the last follow-up when compared to that at 3 months postoperatively ( P<0.05), with no significant difference at later time points between the two groups ( P>0.05). The preoperative cervical Cobb angle and ROM showed no significant differences between the two groups ( P>0.05). There was no significant difference in the Cobb angle between the two groups at 3, 6 or 12 months postoperatively ( P>0.05), while it was (13.6±2.4)° in the intermuscular group at the final follow-up, significantly larger than (10.4±2.8)° in the posterior midline group ( P<0.01). At 3, 6, 12 months postoperatively and at the final follow-up, the cervical ROM were (34.1±6.4)°, (32.6±7.3)°, (31.8±9.1)° and (29.6±8.7)° in the intermuscular group, significantly larger than (23.7±8.3)°, (22.3±7.8)°, (22.5±8.1)° and (20.6±9.3)° in the posterior midline group ( P<0.01). In the intermuscular group, the cervical Cobb angle showed no significant changes at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P>0.05). In the posterior midline group, the Cobb angles were significantly reduced at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P<0.05), showing significant decrease at 12 months postoperatively and at the final follow-up from those at 3, 6 months postoperatively ( P<0.05), no significant difference at 6 months postoperatively from that at 3 months postoperatively ( P>0.05), and significant decrease at the final follow-up from that at 12 months postoperatively ( P>0.05). In the intermuscular group, the cervical ROM were significantly improved at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively and showed further improvement over time ( P<0.05). In the posterior midline group, the cervical ROM were significantly improved at 3, 6, 12 months postoperatively and at the final follow-up when compared to those preoperatively ( P<0.05), showing significant decreases at 6, 12 months postoperatively and at the final follow-up from that at 3 months postoperatively ( P<0.05), significant decreases at the final follow-up from those at 6, 12 months postoperatively ( P<0.05), and no significant difference at 12 months postoperatively from that at 6 months postoperatively ( P>0.05). The ASIA grades showed no significant difference between the two groups preoperatively, at 3, 12 months postoperatively and at the final follow-up ( P>0.05) , but were gradually improved over time in both groups ( P<0.05). The postoperative complication rate was 9%(6/70) in the intermuscular group, significantly lower than 48%(31/65) in the posterior midline group ( P<0.01). Conclusion:Compared to the posterior midline approach, the intermuscular approach for laminoplasty in patients with SCIWORA possesses advantages, including shorter operative time and length of hospital stay, reduced intraoperative blood loss and postoperative drainage, less postoperative neck disability, higher daily life quality, better long-term preservation of cervical lordosis and motion, and a lower complication rate.

Objective:To investigate the clinicopathological features and differential diagnosis of eosinophilic vacuolated tumor (EVT).Methods:Seven cases of EVT with characteristic morphology and unequivocal diagnosis from the Affiliated Hospital of Qingdao University (6 cases), Qingdao, China and the 971 Hospital of PLA Navy (1 case), Qingdao, China between January 2010 and December 2021 were subject to morphological and immunohistochemical analyses. Additionally, whole exome sequencing (WES) was performed in two cases. Twenty-two cases of renal oncocytoma (RO) and 17 cases of eosinophilic chromophobe renal cell carcinoma (eChRCC) diagnosed at the same time were used as controls.Results:Four males and three females with a mean age of 42 years (range: 29-61 years) were included in the study. The tumors were nodular and well-circumscribed, with sizes ranging from 1.5 to 4.5 cm. On cross-section, they appeared gray-red or gray-white, solid, and soft. Tumor cells were arranged in nests, solid sheets, and acinar or small vesicular structures. These cells exhibited eosinophilic cytoplasm with large, prominent clear vacuoles and round nuclei with prominent nucleoli. Perinuclear halos were focally present in four cases, while small tumor cells with sparse cytoplasm and hyperchromatic nuclei were seen in one case. No necrosis or mitosis was noted. Edematous stroma was detected in three cases. All tumors were positive for CD117 and Cathepsin K, but negative for vimentin and CK7. CK20 was positive in scattered individual cells, and Ki-67 positivity ranged from 1% to 4%. Point mutations in MTOR were identified in both patients who were subject to the molecular analysis. Statistical differences in the expression of Cathepsin K, CD10, S-100A1, and Cyclin D1 between EVT and RO ( P<0.05) were significant, so were the differences in the expression of Cathepsin K, CD10, CK7 and claudin 7 between EVT and eChRCC ( P<0.001). Seven patients were followed up for 4 to 96 months (mean, 50 months), with no recurrences or metastases. Conclusions:EVT is a rare renal tumor that shares morphological and immunophenotypic features with RO and eChRCC, and it is closely linked to the TSC/MTOR pathway. The presence of large prominent transparent vacuoles in eosinophilic cytoplasm along with conspicuous nucleoli is its key morphological characteristics. The use of combined immunohistochemical stains greatly aids in its diagnosis. Typically, the tumor exhibits indolent biological behaviors with a favorable prognosis.

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.