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Objective: To compare the effectiveness of robot-assisted and traditional freehand screw placement in the treatment of atlantoaxial dislocation., Methods: The clinical data of 55 patients with atlantoaxial dislocation who met the selection criteria between January 2021 and January 2024 were retrospectively analyzed. According to different screw placement methods, they were divided into the traditional group (using the traditional freedhand screw placement, 31 cases) and the robot group (using the Mazor X robot-assisted screw placement, 24 cases). There was no significant difference in gender, age, body mass index, etiology, and preoperative visual analogue scale (VAS) score, cervical spine Japanese Orthopaedic Association (JOA) score between the two groups ( P >0.05). The operation time, intraoperative blood loss, operation cost, and intraoperative complications were recorded and compared between the two groups. The VAS score and cervical spine JOA score were used to evaluate the improvement of pain and cervical spinal cord function before operation and at 1 month after operation. CT examination was performed at 3 days after operation, and the accuracy of screw placement was evaluated according to Neo grading criteria., Results: All the 55 patients successfully completed the operation. The operation time, intraoperative blood loss, and operation cost in the robot group were significantly higher than those in the traditional group ( P <0.05). A total of 220 C 1 and C 2 pedicle screws were inserted in the two groups, and 94 were inserted in the robot group, with an accuracy rate of 95.7%, among them, 2 were inserted by traditional freehand screw placement due to bleeding caused by intraoperative slip. And 126 pedicle screws were inserted in the traditional group, with an accuracy rate of 87.3%, which was significantly lower than that in the robot group ( P <0.05). There were 1 case of venous plexus injury in the robot group and 3 cases in the traditional group, which improved after pressure hemostasis treatment. No other intraoperative complication such as vertebral artery injury or spinal cord injury occurred in both groups. All patients were followed up 4-16 months with an average of 6.6 months, and there was no significant difference in the follow-up time between the two groups ( P >0.05). Postoperative neck pain significantly relieved in both groups, and neurological symptoms relieved to varying degrees. The VAS score and cervicle spine JOA score of both groups significantly improved at 1 month after operation when compared with preoperative scores ( P <0.05), and there was no significant difference in the score change between the two groups ( P >0.05)., Conclusion: In the treatment of atlantoaxial dislocation, the accuracy of robot-assisted screw placement is superior to the traditional freedhand screw placement.

Objective: To investigate the effectiveness of computer-assisted and robot-assisted atlantoaxial pedicle screw implantation for the treatment of reversible atlantoaxial dislocation (AAD)., Methods: The clinical data of 42 patients with reversible AAD admitted between January 2020 and June 2023 and met the selection criteria were retrospectively analyzed, of whom 23 patients were treated with computer-assisted surgery (computer group) and 19 patients were treated with Mazor X spinal robot-assisted surgery (robot group). There was no significant difference in gender, age, T value of bone mineral density, body mass index, etiology, and preoperative Japanese Orthopaedic Association (JOA) score, Neck Dysfunction Index (NDI) between the two groups ( P >0.05). The operation time, screw implantation time, intraoperative blood loss, hand and wrist radiation exposure, and complications were recorded and compared between the two groups. Gertzbein classification was used to evaluate the accuracy of screw implantation. JOA score and NDI were used to evaluate the function before operation, at 3 days after operation, and at last follow-up. At last follow-up, the status of screws and bone fusion were observed by neck three-dimensional CT., Results: The operation time and hand and wrist radiation exposure of the computer group were significantly longer than those of the robot group ( P <0.05), and there was no significant difference in the screw implantation time and intraoperative blood loss between the two groups ( P >0.05). All patients were followed up 11-24 months, with an average of 19.6 months. There was no significant difference in the follow-up time between the two groups ( P >0.05). There was no significant difference in the accuracy of screw implantation between the two groups ( P >0.05). Except for 1 case of incision infection in the computer group, which improved after antibiotic treatment, there was no complication such as nerve and vertebral artery injury, screw loosening, or breakage in the two groups. The JOA score and NDI significantly improved in both groups at 3 days after operation and at last follow-up ( P <0.05) compared to those before operation, but there was no significant difference between the two groups ( P >0.05). At last follow-up, 21 patients (91.3%) in the computer group and 18 patients (94.7%) in the robot group achieved satisfactory atlantoaxial fusion, and there was no significant difference in the fusion rate between the two groups ( P >0.05)., Conclusion: Computer-assisted or robot-assisted atlantoaxial pedicle screw implantation is safe and effective, and robotic navigation shortens operation time and reduces radiation exposure.

Objective: To explore the safety and effectiveness of one-stage posterior eggshell osteotomy and long-segment pedicle screw fixation in the treatment of ankylosing spondylitis kyphosis combined with acute thoracolumbar vertebral fracture., Methods: A clinical data of 20 patients with ankylosing spondylitis kyphosis combined with acute thoracolumbar spine fracture, who were treated with one-stage posterior eggshell osteotomy and long-segment pedicle screw fixation between April 2016 and January 2022, was retrospectively analyzed. Among them, 16 cases were male and 4 cases were female; their ages ranged from 32 to 68 years, with an average of 45.9 years. The causes of injury included 10 cases of sprain, 8 cases of fall, and 2 cases of falling from height. The time from injury to operation ranged from 1 to 12 days, with an average of 7.1 days. The injured segment was T 11 in 2 cases, T 12 in 2 cases, L 1 in 6 cases, and L 2 in 10 cases. X-ray film and CT showed that the patients had characteristic imaging manifestations of ankylosing spondylitis, and the fracture lines were involved in the anterior, middle, and posterior columns and accompanied by different degrees of kyphosis and vertebral compression; and MRI showed that 12 patients had different degrees of nerve injuries. The operation time, intraoperative bleeding, intra- and post-operative complications were recorded. The visual analogue scale (VAS) score and Oswestry disability index (ODI) were used to evaluate the low back pain and quality of life, and the American spinal cord injury association (ASIA) classification was used to evaluate the neurological function. X-ray films were taken, and local Cobb angle (LCA) and sagittal vertical axis (SVA) were measured to evaluate the correction of the kyphosis., Results: All operations were successfully completed and the operation time ranged from 127 to 254 minutes (mean, 176.3 minutes). The amount of intraoperative bleeding ranged from 400 to 950 mL (mean, 722.5 mL). One case of dural sac tear occurred during operation, and no cerebrospinal fluid leakage occurred after repair, and the rest of the patients did not suffer from neurological and vascular injuries, cerebrospinal fluid leakage, and other related complications during operation. All incisions healed by first intention without infection or fat liquefaction. All patients were followed up 8-16 months (mean, 12.5 months). The VAS score, ODI, LCA, and SVA at 3 days after operation and last follow-up significantly improved when compared with those before operation ( P <0.05), and the difference between 3 days after operation and last follow-up was not significant ( P >0.05). The ASIA grading of neurological function at last follow-up also significantly improved when compared with that before operation ( P <0.05), including 17 cases of grade E and 3 cases of grade D. At last follow-up, all bone grafts achieved bone fusion, and no complications such as loosening, breaking of internal fixation, and pseudoarthrosis occurred., Conclusion: One-stage posterior eggshell osteotomy and long-segment pedicle screw fixation is an effective surgical procedure for ankylosing spondylitis kyphosis combined with acute thoracolumbar vertebral fracture. It can significantly relieve patients' clinical symptoms and to some extent, alleviate the local kyphotic deformity.

Objective: To explore the effectiveness of unilateral percutaneous vertebroplasty (PVP) through mild side and severe side approaches in the treatment of elderly osteoporotic vertebral compression fracture (OVCF)., Methods: The clinical data of 100 patients with OVCF with symptoms on one side who were admitted between June 2020 and June 2021 and met the selection criteria were retrospectively analyzed. The patients were divided into the severe side approach group (group A) and the mild side approach group (group B) according to the cement puncture access during PVP, with 50 cases in each group. There was no significant difference between the two groups in terms of general information such as gender composition, age, body mass index, bone density, damaged segments, disease duration, and chronic comorbidities ( P >0.05). The lateral margin height of the vertebral body on the operated side in group B was significantly higher than that of group A ( P <0.001). The pain level and spinal motor function were evaluated using the pain visual analogue scale (VAS) score and Oswestry disability index (ODI) before operation, at 1 day, 1 month, 3 months, and 12 months after operation in both groups, respectively., Results: No intraoperative or postoperative complications such as bone cement allergy, fever, incision infection, and transient hypotension occurred in both groups. Four cases of bone cement leakage occurred in group A (3 cases of intervertebral leakage and 1 case of paravertebral leakage), and 6 cases of bone cement leakage occurred in group B (4 cases of intervertebral leakage, 1 case of paravertebral leakage, and 1 case of spinal canal leakage), and none of them had neurological symptoms. Patients in both groups were followed up 12-16 months, with a mean of 13.3 months. All fractures healed and the healing time ranged from 2 to 4 months, with a mean of 2.9 months. The patients had no complication related to infection, adjacent vertebral fracture, or vascular embolism during follow-up. At 3 months postoperatively, the lateral margin height of the vertebral body on the operated side in groups A and B were improved when compared with preoperative ones, and the difference between pre- and post-operative lateral margin height of the vertebral body in group A was higher than that in group B, all showing significant differences ( P <0.001). The VAS scores and ODI in both groups improved significantly at all postoperative time points when compared with those before operation, and further improved with time after operation ( P <0.05). The differences in VAS scores and ODI between the two groups before operation were not significant ( P >0.05); VAS scores and ODI in group A were significantly better than those in group B at 1 day, 1 month, and 3 months after operation ( P <0.05), but no significant difference was found between the two groups at 12 months after operation ( P >0.05)., Conclusion: Patients with OVCF have more severe compression on the more symptomatic side of the vertebral body, and patients with PVP have better pain relief and better functional recovery when cement is injected through the severe symptomatic side.

Objective: To investigate the risk factors of adjacent fractures after percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fracture (OVCF)., Methods: A total of 2 216 patients who received PVP due to symptomatic OVCF between January 2014 and January 2017 and met the selection criteria were selected as study subjects. The clinical data was collected, including gender, age, height, body mass, history of smoking and drinking, whether the combination of hypertension, diabetes, coronary arteriosclerosis, chronic obstructive pulmonary disease (COPD), bone mineral density, the number of fractured vertebrae, the amount of cement injected into single vertebra, the cement leakage, and whether regular exercise after operation, whether regular anti-osteoporosis treatment after operation. Firstly, single factor analysis was performed on the observed indicators to preliminarily screen the influencing factors of adjacent fractures after PVP. Then, logistic regression analysis was carried out for relevant indicators with statistical significance to screen risk factors., Results: All patients were followed up 12-24 months, with an average of 15.8 months. Among them, 227 patients (10.24%) had adjacent fractures. The univariate analysis showed that there were significant differences between the fracture group and non-fracture group in age, gender, preoperative bone density, history of smoking and drinking, COPD, the number of fractured vertebrae and the amount of bone cement injected into the single vertebra, as well as regular exercise after operation, regular anti-osteoporosis treatment after operation ( P <0.05). Further multivariate logistic regression analysis showed that the elderly and female, history of smoking, irregular exercise after operation, irregular anti-osteoporosis treatment after operation, low preoperative bone density, large number of fractured vertebrae, and small amount of bone cement injected into the single vertebra were risk factors for adjacent fractures after PVP in OVCF patients ( P <0.05)., Conclusion: The risk of adjacent fractures after PVP increases in elderly, female patients with low preoperative bone mineral density, large number of fractured vertebrae, and insufficient bone cement injection. The patients need to quit smoking, regular exercise, and anti-osteoporosis treatment after PVP.

Objective: After using hyaluronic acid (HA) to modify curcumin (CUR), the effects of calcium phosphate cement (CPC) combined with HA/CUR on the proliferation and osteogenesis of osteoblasts were investigated., Methods: First, HA and CUR were esterified and covalently combined to prepare HA/CUR, and the characteristics were observed and the infrared spectrum was tested. Then, HA, CUR, and HA/CUR were mixed with CPC according to 5% ( W / W ) to prepare HA-CPC, CUR-CPC, and HA/CUR-CPC, respectively. Setting time detection, scanning electron microscope observation, injectable performance test, and compression strength test were conducted; and the CPC was used as a control. Osteoblasts were isolated and cultured from the skull of newborn Sprague Dawley rats, and the 2nd generation cells were cultured with the 4 types of bone cement, respectively. The effects of HA/CUR-CPC on the proliferation and osteogenesis of osteoblasts were estimated by the scanning electron microscopy observation, live/dead cell fluorescence staining, cell counting, osteopontin (OPN) immunofluorescence staining, alkaline phosphatase (ALP) staining,and alizarin red staining., Results: Infrared spectroscopy test showed that HA and CUR successfully covalently combined. The HA/CUR-CPC group had no significant difference in initial setting time, final setting time, injectable rate, and compressive strength when compared with the other 3 groups ( P >0.05); scanning electron microscope observation showed that HA/CUR was scattered on CPC surface. After co-culture of bone cement and osteoblasts, scanning electron microscopy observation showed that the osteoblasts, which had normal morphology and the growth characteristics of osteoblasts, clustered and adhered to HA/CUR-CPC. There was no significant difference in cell survival rate between HA/CUR-CPC group and other groups ( P >0.05), and the number of cells significantly increased ( P <0.05); the degrees of OPN immunofluorescence staining, ALP staining, and alizarin red staining were stronger than other groups., Conclusion: HA/CUR-CPC has good biocompatibility and mechanical properties, which can promote the proliferation and osteogenesis of osteoblasts.

Objective: To explore the safety and effectiveness of polymethylmethacrylate-augmented screw fixation (PASF) in the treatment of elderly thoracolumbar tuberculosis combined with severe osteoporosis., Methods: The clinical data of 20 elderly patients with thoracolumbar tuberculosis and severe osteoporosis who underwent PASF after anterior or posterior debridement and bone grafting and met the selection criteria between December 2012 and December 2014 were retrospectively analyzed. There were 8 males and 12 females with an average age of 68.5 years (range, 65-72 years). T value of bone mineral density was -4.2 to -3.6, with an average of -3.9. There were 12 cases of thoracic tuberculosis, 3 cases of thoracolumbar tuberculosis, and 5 cases of lumbar tuberculosis. The diseased segments involved T 3 -L 4 , including 11 cases of single-segment disease, 6 cases of double-segment disease, and 3 cases of multi-segment disease. The disease duration was 3-9 months, with an average of 6 months. The preoperative spinal nerve function of the patients was evaluated by the American Spinal Injury Association (ASIA) grading. There were 2 cases of grade A, 5 cases of grade B, 6 cases of grade C, 4 cases of grade D, and 3 cases of grade E. Postoperative imaging examination was used to evaluate the bone graft fusion and paravertebral abscess absorption, and to measure the Cobb angle of the segment to evaluate the improvement of kyphosis. The levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were tested. The visual analogue scale (VAS) score, Oswestry disability index (ODI), and ASIA grading were used to evaluate the effectivreness before operation, at 1 month after operation, and at last follow-up. The clinical cure of tuberculosis was also evaluated., Results: All operation successfully completed. The operation time was 154-250 minutes, with an average of 202 minutes; the intraoperative blood loss was 368-656 mL, with an average of 512 mL. All 20 patients were followed up 18-42 months, with an average of 26.8 months. The postoperative pain and symptoms of tuberculosis in all patients relieved, and the paravertebral abscess was absorbed, reaching the cure standard for spinal tuberculosis. All bone grafts fusion achieved within 1 year after operation. Only 1 case had asymptomatic bone cement leakage into the paravertebral veins, and the remaining patients had no serious complications such as bone cement leakage in the spinal canal, pulmonary embolism, and neurovascular injury. At last follow-up, spinal cord nerve function significantly improved when compared with preoperative one. Among them, ASIA grading were 7 cases of grade C, 8 cases of grade D, and 5 cases of grade E, showing significant difference when compared with preoperative one ( Z =2.139, P =0.000). VAS score, ODI score, segmental Cobb angle, ESR, and CRP at 1 month after operation and at last follow-up were significantly improved when compared with preoperative ones ( P <0.05); there was no significant difference between 1 month after operation and last follow-up ( P >0.05). During the follow-up, no complications such as failure of internal fixation, proximal junctional kyphosis, or tuberculosis recurrence occurred., Conclusion: For elderly patients with thoracolumbar tuberculosis and severe osteoporosis, PASF treatment is safe and effective.

Objective: To investigate the effect and safety of tranexamic acid sequential rivaroxaban on perioperative blood loss and preventing thrombosis for elderly patients during lumbar interbody fusion (LIF) with a prospective randomized controlled study., Methods: Between April and October 2019, the elderly patients with lumbar degenerative diseases requiring LIF were included in the study, among which were 80 patients met the selection criteria. According to the antifibrinolysis and anticoagulation protocols, they were randomly divided into a tranexamic acid sequential rivaroxaban group (trial group) and a simple rivaroxaban group (control group) on average. Finally, 69 patients (35 in the trial group and 34 in the control group) were included for comparison. There was no significant difference in general data ( P >0.05) such as gender, age, body mass index, disease duration, diseased segment, type of disease, and preoperative hemoglobin between the two groups. The operation time, intraoperative blood loss, drainage within 3 days after operation, perioperative total blood loss, and proportion of blood transfusion patients were compared between the two groups, as well as postoperative venous thrombosis of lower extremities, pulmonary embolism, and bleeding-related complications., Results: The operations of the two groups completed successfully, and there was no significant difference in the operation time ( P >0.05); the intraoperative blood loss, drainage within 3 days after operation, and perioperative total blood loss in the trial group were significantly lower than those in the control group ( P <0.05). The proportion of blood transfusion patients in the trial group was 25.71% (9/35), which was significantly lower than that in the control group [52.94% (18/34)] ( χ 2 =5.368, P =0.021). Postoperative incision bleeding occurred in 4 cases of the trial group and 3 cases of the control group, and there was no significant difference in bleeding-related complications between the two groups ( P =1.000). There was 1 case of venous thrombosis of the lower extremities in each group after operation, and there was no significant difference in the incidence between the two groups ( P =1.000). Besides, no pulmonary embolism occurred in the two groups., Conclusion: Perioperative use of tranexamic acid sequential rivaroxaban in elderly LIF patients can effectively reduce the amount of blood loss and the proportion of blood transfusion patients without increasing the risk of postoperative thrombosis.

Objective: To compare the safety and accuracy of manual and robot-assisted cortical bone trajectory (CBT) screws fixation in the treatment of lumbar degenerative diseases with osteoporosis., Methods: The clinical data of 58 cases of lumbar degenerative disease with osteoporosis treated by CBT screw fixation between February 2017 and February 2019 were analyzed retrospectively. Among them, 29 cases were fixed with CBT screws assisted by robot (group A), 29 cases were fixed with CBT screws by hand (group B). There was no significant difference between the two groups in terms of gender, age, body mass index, lesion type, T-value of bone mineral density, and operative segment ( P >0.05), with comparability. The accuracy of implant was evaluated by Kaito's grading method, and the invasion of CBT screw to the superior articular process was evaluated by Babu's method., Results: The operation time and intraoperative blood loss in group A were significantly less than those in group B ( t =-8.921, P =0.000; t =-14.101, P =0.000). One hundred and sixteen CBT screws were implanted in the two groups. At 3 days after operation, according to the Kaito's grading method, the accuracy of implant in group A was 108 screws of grade 0, 6 of grade 1, and 2 of grade 2; and in group B was 86 screws of grade 0, 12 of grade 1, and 18 of grade 2; the difference was significant ( Z =4.007, P =0.000). There were 114 accepted screws (98.3%) in group A and 98 (84.5%) in group B, the difference was significant ( χ 2 =8.309, P =0.009). At 3 days after operation, according to Babu's method, there were 85 screws in grade 0, 3 in grade 1, and 2 in grade 2 in group A; and in group B, there were 91 screws in grade 0, 16 in grade 1, 5 in grade 2, and 4 in grade 3; the difference was significant ( Z =7.943, P =0.000). No serious injury of spinal cord, nerve, and blood vessel was found in the two groups. One patient in group A had delayed cerebrospinal fluid leakage, and 2 patients in group B had mild anemia. Both groups were followed up 10-14 months (mean, 11.6 months). The neurological symptoms were improved, and no screw loosening or fracture was found during the follow-up., Conclusion: Compared with manual implantation of CBT screw, robot-assisted spinal implant has higher accuracy, lower incidence of invasion of superior articular process, and strong holding power of CBT screw, which can be applied to the treatment of lumbar degenerative diseases with osteoporosis.

Objective: To investigate the clinical feasibility of full-endoscopic decompression for the treatment of single-level cervical disc herniation via anterior transcorporeal approach., Methods: According to the inclusion and exclusion criteria, 21 patients with cervical disc herniation who received full-endoscopic decompression via anterior transcorporeal approach between September 2014 and March 2016 were retrospectively analyzed. There were 12 males and 9 females with an age ranged from 32 to 65 years, with an average of 48.5 years. The duration of symptoms ranged from 6 to 18 weeks, with an average of 10.5 weeks. According to the Nurick grading of spinal cord symptoms, there were 2 cases with grade 1, 7 cases with grade 2, and 12 cases with grade 3. Operative segment was C 3, 4 in 2 cases, C 4, 5 in 8 cases, C 5, 6 in 9 cases, and C 6, 7 in 2 cases. The operation time and related complications were recorded. The central vertical height of the vertebral body and the diseased segment space were measured on the cervical X-ray film. The neck and shoulder pain were evaluated by visual analogue scale (VAS) score; Japanese Orthopaedic Association (JOA) score was used to evaluate the improvement of neurological function in patients. The MRI of cervical spine was reexamined at 3 months after operation, and the CT of cervical spine was reexamined at 12 months after operation. The decompression of spinal cord and the healing of bone canal in the vertebral body were further evaluated., Results: Full-endoscopic decompression via anterior transcorporeal approach were achieved at all 21 patients. The operation time was 85-135 minutes, with an average of 96.5 minutes. All patients were followed up 24-27 months, with an average of 24.5 months. There was no complication such as residual nucleus pulposus, spinal cord injury, large esophageal vessels injury, pleural effusion, endplate collapse, intraspinal hematoma, cervical spine instability, protrusion of disc in the same segment, or kyphosis. Both VAS scores of neck and shoulder pain and JOA scores were significantly improved at 12 months after operation ( P <0.05). At 3 months after operation, it was confirmed by the cervical MRI that neural decompression was sufficient and the abnormal signal was also degraded in the patients with intramedullary high signal at T2-weighted image. The cervical CT showed that bone healing were achieved in the surgical vertebral bodies of all patients at 12 months after operation. At 24 months after operation, the central vertical height of the diseased segment space significantly decreased compared with preoperative one ( t =2.043, P =0.035); but there was no significant difference in the central vertical height of the vertebral body between pre- and post-operation ( t =0.881, P =0.421)., Conclusion: Full-endoscopic decompression via anterior transcorporeal approach, integrating the advantages of the endoscopic surgery and the transcorporeal approach, provide an ideal and thorough decompression of the ventral spinal cord with satisfactory clinical and radiographic results.

Objective: To investigate the effect of hydrogen peroxide on anti-infection and reducing postoperative drainage in multi-segmental lumbar surgery., Methods: A clinical data of 510 patients with multi-segmental lumbar degenerative diseases who were treated with surgery between January 2017 and January 2018 was retrospectively analyzed. In study group, the incisions of 230 cases were washed with hydrogen peroxide before suture. In control group, the incisions of 280 cases were washed with normal saline before suture. There was no significant difference in gender, age, lesion type, disease duration, operative segment, and other clinical data between the two groups ( P >0.05). The operation time, intraoperative blood loss, postoperative drainage volume, and postoperative incidence of infection were recorded and compared between the two groups. The Centers for Disease Control and Prevention (CDC) standard was used to evaluate infection, which was divided into superficial infection and deep infection., Results: All operations completed successfully. There was no significant difference in operation time and intraoperative blood loss between the two groups ( P >0.05). The postoperative drainage volume in the study group was significantly less than that in the control group ( t =-2.990, P =0.005). A total of 13 patients developed infection after operation, including 10 cases of superficial infection (2 cases in the study group and 8 cases in the control group) with the infection time of (7.3±1.5) days, and 3 cases of deep infection (all in the control group) with the infection time of (16.6±3.1) days. The incidences of superficial and deep infections in the study group were lower than those in the control group, but there was no significant difference between the two groups ( χ 2 =2.595, P =0.123; P =0.256). All the superficial infections were Staphylococcus aureus infection and recovered after active dressing change. Among the patients with deep infections, 2 cases were infected by Staphylococcus aureus and 1 case was infected by Escherichia coli ; and the incisions healed after being washed and sutured thoroughly, and active dressing change., Conclusion: The incidence of postoperative infection and postoperative drainage volume can be reduced by washing the incision with hydrogen peroxide in multi-segmental lumbar surgery.

Objective: To compare differences in the maintenance of cervical curvature after anterior cervical surgery between zero-profile and self-locking intervertebral cage and plate-cage construct (PCC)., Methods: A clinical data of 100 patients with single-segment cervical disc herniation who were treated with anterior cervical discectomy and fusion were retrospectively analyzed between January 2015 and January 2016. Among them, 50 patients were treated with the zero-profile and self-locking intervertebral cage (group A) and 50 patients with the PCC (group B). There was no significant difference between the two groups in age, gender, bone mineral density, disease duration, operative segment, and preoperative visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height ( P >0.05). The operation time and intraoperative blood loss were recorded. The postoperative VAS and JOA scores were used to evaluate the clinical efficacy. The C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height were measured on lateral X-ray films, and the interbody fusion was evaluated according to Pitzen's criteria., Results: The operation time in group A was significantly shorter than that in group B ( t =2.442, P =0.021), but there was no significant difference in the intraoperative blood loss between the two groups ( t =0.812, P =0.403). All patients were followed up 24-36 months, with an average of 28.5 months. According to Pitzen's criteria for cervical interbody fusion, bone fusion achieved in both groups. The VAS score, JOA score, C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height of the two groups at 1 and 24 months after operation were significantly improved when compared with those before operation ( P <0.05). The C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height of group A at 24 months changed significantly compared with those at 1 month ( P <0.05). The other indexes of the two groups showed no significant difference between the different time points after operation ( P >0.05). There were significant differences in C 2-7 cervical curvature, segmental Cobb angle, and adjacent vertebral height between the two groups at 24 months after operation ( P <0.05); but there was no significant difference in the clinical indexes at 1 and 24 months and the imaging indexes at 1 month between the two groups ( P >0.05)., Conclusion: Compared with the PCC, the zero-profile and self-locking intervertebral cage can significantly shorten the operation time and obtain the same clinical efficacy, but the intervertebral height loss and secondary cervical curvature change after operation is more serious.

Objective: To compare the effectiveness and screw planting accuracy of percutaneous reduction and internal fixation with robot and traditional fluoroscopy-assisted in the treatment of single-level thoracolumbar fractures without neurological symptoms., Methods: The clinical data of 58 patients with single-level thoracolumbar fractures without neurological symptoms between December 2016 and January 2018 were retrospectively analysed. According to different surgical methods, the patients were divided into group A (28 cases underwent robot-assisted percutaneous reduction and internal fixation) and group B (30 cases underwent fluoroscopy-assisted percutaneous reduction and internal fixation). There was no neurological symptoms, other fractures or organ injuries in the two groups. There was no significant difference in general data of age, gender, fracture location, AO classification, time from injury to surgery, and preoperative vertebral anterior height ratio, sagittal Cobb angle, visual analogue scale (VAS) score, and Oswestry disability index (ODI) score between the two groups ( P >0.05). The screw placement time, operation time, intraoperative blood loss, intraoperative fluoroscopy frequency, hospitalization time, operation cost, postoperative complications, VAS score, ODI score, anterior vertebral height ratio, and sagittal Cobb angle before operation, at 3 days, 6 months after operation, and at last follow-up were recorded and compared between the two groups. The accuracy of the pedicle screw placement was evaluated by Neo's criteria., Results: The screw placement time, operation time, and intraoperative fluoroscopy frequency of group A were significantly less than those of group B, and the operation cost was significantly higher than that of group B ( P <0.05). But there was no significant difference in intraoperative blood loss and hospitalization time between the two groups ( P >0.05). Both groups were followed up 12-24 months, with an average of 15.2 months. The accuracy rate of screw placement in groups A and B was 93.75% (150/160) and 84.71% (144/170), respectively, and the difference was significant ( χ 2 =5.820, P =0.008). Except for 1 case of postoperative superficial infection in group A and wound healing after dressing change, there was no complication such as neurovascular injury, screw loosening and fracture in both groups, and there was no significant difference in the incidence of complications between the two groups ( χ 2 =0.625, P =0.547). The anterior vertebral height ratio, sagittal Cobb angle, VAS score, and ODI score of the two groups were significantly improved ( P <0.05); there was no significant difference between the two groups at all time points after operation ( P >0.05)., Conclusion: The spinal robot and traditional fluoroscopy-assisted percutaneous reduction and internal fixation can both achieve satisfactory effectiveness in the treatment of single-level thoracolumbar fractures without neurological symptoms. However, the former has higher accuracy, fewer fluoroscopy times, shorter time of screw placement, and lower technical requirements for the operator. It has wide application potential.

Objective: To investigate the safety and effectiveness of debridement and interbody fusion via posterior pedicle lateral approach in treatment of ankylosing spondylitis with thoracolumbar Andersson lesion (AL)., Methods: Between October 2011 and January 2017, 10 patients of ankylosing spondylitis with thoracolumbar AL were treated with debridement via posterior pedicle lateral approach and interbody fusion with bone grafting. There were 8 males and 2 females with an average age of 48.8 years (range, 31-79 years). The disease duration was 1.5-48.0 months (mean, 10.6 months). All patients were single-segment lesion, including 3 cases of T 10, 11 , 4 cases of T 11, 12 , and 3 cases of T 12 , L 1 . The preoperative visual analogue scale (VAS) score was 8.0±0.8, the Oswestry disability index (ODI) was 68.8%±5.5%, and the Cobb angle of local kyphosis was (26.3±7.1)°. According to American Spinal Injury Association (ASIA) scoring system, neurological impairment was assessed in 1 case of grade C, 4 cases of grade D, and 5 cases of grade E., Results: All the operations of 10 patients completed successfully. The operation time was 120-185 minutes (mean, 151.5 minutes), and the intraoperative blood loss was 300-750 mL (mean, 450.0 mL). Dural sac tear occurred in 1 case during operation and was repaired, with no cerebrospinal fluid leakage after operation. All patients were followed up 24-50 months (mean, 31.2 months). At last follow-up, the VAS score was 1.9±0.9 and ODI was 13.0%±3.0%, showing significant differences when compared with preoperative ones ( t =17.530, P =0.000; t =31.890, P =0.000). Neurological function was improved significantly at 24 months after operation, and rated as ASIA grade E. The Cobb angles were (12.6±4.6)° at 3 days and (13.6±4.6)° at 24 months after operation, which were significantly different from those before operation ( P <0.05); there was no significant difference between 3 days and 24 months after operation ( P >0.05). At 24 months after operation, the grafted bone obtained good fusion at AL segment. During the follow-up, there was no failure of internal fixation such as nail withdrawal, broken nail, and broken rod., Conclusion: Debridement and interbody fusion via posterior pedicle lateral approach for the ankylosing spondylitis with thoracolumbar AL can achieve satisfactory effectiveness, good fusion, and a certain correction of local kyphosis.

Objective: To investigate the effectiveness of posterior short-segmental fixation with bone cement augmentation in treatment of stage Ⅲ Kümmell's disease with spinal canal stenosis., Methods: Between June 2012 and January 2017, 36 patients with stage Ⅲ Kümmell's disease and spinal canal stenosis were treated by posterior short-segmental fixation and bone cement augmentation. There were 12 males and 24 females, aged 55-83 years (mean, 73.5 years). The disease duration ranged from 2 to 8 months, with an average of 4.6 months. Preoperative bone mineral density examination showed that all patients had different degrees of osteoporosis in the spines. The lesion segments included T 10 in 4 cases, T 11 in 7 cases, T 12 in 8 cases, L 1 in 9 cases, and L 2 in 8 cases. The preoperative neural function was classified as grade B in 4 cases, grade C in 12 cases, grade D in 13 cases, and grade E in 7 cases according to Frankle classification. The operation time, intraoperative blood loss, and the volume of injected bone cement, and hospital stay were recorded. The visual analogue scale (VAS) score, Oswestry Disability Index (ODI), kyphotic Cobb angle, and the height of anterior edge of injured vertebra were recorded before operation, at 1 week after operation, and at last follow-up; and the leakage of bone cement was observed., Results: All operations were completed successfully. The operation time was 90-145 minutes (mean, 110.6 minutes); the intraoperative blood loss was 198-302 mL (mean, 242.5 mL); the volume of injected bone cement was 8.3-10.5 mL (mean, 9.2 mL); the hospital stays were 7-12 days (mean, 8.3 days). All patients were followed up 12-26 months (mean, 24.5 months). At 1 week after operation, the neural function was classified as grade B in 2 cases, grade C in 8 cases, grade D in 12 cases, and grade E in 14 cases, which was significantly improved when compared with that before operation ( Z =2.000, P =0.047). The VAS score, ODI, the height of anterior edge of injured vertebra, and Cobb angle were significantly improved at 1 week and last follow-up when compared with preoperative values ( P <0.05); but there was no significant difference between 1 week and last follow-up ( P >0.05). Two cases had asymptomatic cement leakage to the intervertebral disc at 1 week after operation; and 1 case had adjacent vertebral fracture at 8 months after operation. No complication such as loosening or breaking of internal fixator occurred during the follow-up., Conclusion: Posterior short-segmental fixation with bone cement augmentation is a safe and effective surgical scheme for stage Ⅲ Kümmell's disease combined with spinal canal stenosis, which can avoid the aggravation of nerve injury and complications related to staying in bed.

Objective: To evaluate the effectiveness and safety of preoperative feeding artery occlusion on vertebral resection of invasive vertebral hemangioma., Methods: The clinical data of 20 patients with invasive vertebral hemangioma who received posterior lumbar vertebral body resection, bone grafting, fusion and internal fixation between March 2010 and March 2017 were retrospectively analyzed. According to whether feeding artery occlusion was performed before operation, the patients were divided into group A (11 cases, tumor feeding artery occlusion before operation) and group B (9 cases, no tumor feeding artery occlusion before operation). There was no significant difference in gender, age, lesion segment, and disease duration between the two groups ( P >0.05). The operation time, intraoperative blood loss, postoperative drainage volume, blood transfusion volume, and ambulant time after surgery, hospitalization time, and deep venous thrombosis of lower extremities were recorded and compared between the two groups. Pain improvement was evaluated by visual analogue scale (VAS) score., Results: The operation time, intraoperative blood loss, blood transfusion volume, and ambulant time after surgery were significantly less in group A than those in group B ( P <0.05). There was no significant difference in postoperative drainage volume and hospitalization time between the two groups ( P >0.05). Five patients (3 in group A and 2 in group B) suffered from pleural tear due to intraoperative pleural adhesions. Closed thoracic drainage tubes were placed immediately after suture and extubated on 3-5 days. Both groups were followed up 1-1.5 years, with an average of 1.35 years. In group B, 1 patient died of pulmonary embolism at 7 days after operation; and 2 patients developed deep venous thrombosis of lower extremity after operation, who were treated with inferior vena cava filter and thrombolytic therapy, and recovered well after operation. The local pain of the other patients was significantly relieved after operation, and the pain disappeared at 1 month after operation. The VAS scores of the two groups at 3 days after operation were significantly improved when compared with those before operation ( P <0.05). There was no significant difference in VAS scores between the two groups before operation and at 3 days after operation ( P >0.05). Three patients (2 in group A and 1 in group B) who had neurological symptoms were significantly relieved after surgery. Bone healing was achieved in both groups at 1 year after operation. No fracture or loosening of internal fixator occurred during follow-up., Conclusion: Nutritional artery occlusion before vertebrectomy for invasive vertebral hemangioma can effectively reduce intraoperative blood loss, operation time, perioperative blood transfusion, and other perioperative complications.

Objective: To investigate the effectiveness of modified direction-changeable lumbar Cage in transforaminal lumbar interbody fusion (TLIF)., Methods: A retrospective analysis was made of 161 patients with single segment L 4 or L 5 isthmic spondylolisthesis treated between January 2013 and December 2015. According to the implantation of Cage, they were divided into trial group (85 cases, modified direction-changeable lumbar Cage implanted in TLIF) and control group (76 cases, traditional nondirection-changeable Cage implanted in TLIF). There was no significant difference in the general data of gender, age, disease duration, slippage segment, and slippage grade between the two groups ( P >0.05). The intraoperative implantation time of Cage, Cage position adjustments times, fluoroscopy times during implantation of Cage, fluoroscopy exposure time, and total operation time were recorded and compared between the two groups. Visual analogue scale (VAS) and Oswestry disability index (ODI) scores were used to evaluate the effectiveness of the patients before operation, and at 3, 6, and 12 months after operation, and the incidence of complications was recorded and analyzed. CT examinations were performed at 6 and 12 months after operation, and lumbar fusion was evaluated by Bridwell criteria., Results: The intraoperative implantation time of Cage, Cage position adjustments times, fluoroscopy times during implantation of Cage, fluoroscopy exposure time, and total operation time in trial group were significant less than those in control group ( P <0.05). All the 161 patients were followed up 12-18 months (mean, 14.3 months). There was 1 case of dural sac tear in the trial group and 1 case of superficial infection in the control group; no complication such as dural tear and infection occurred in other patients. The fusion rate was 76.5% (64/85) in the trial group and 57.9% (44/76) in the control group at 6 months after operation, showing significant difference ( χ 2 =6.44, P =0.02); at 12 months after operation, the fusion rate was 96.5% (82/85) in the trial group and 90.8% (69/76) in the control group (including 3 cases of Cage displacement and 4 cases of screw breakage), showing no significant difference in the fusion rate between the two groups ( χ 2 =1.54, P =0.26). The VAS and ODI scores of the two groups decreased gradually at 3, 6, and 12 months after operation, and improved significantly when compared with those before operation ( P <0.05). There was no significant difference in VAS and ODI scores between the two groups before and after operation ( P >0.05)., Conclusion: Both Cages can obtain the similar effectiveness. The modified direction-changeable lumbar Cage can significantly reduce the fluoroscopy times and radiation dose during TLIF, shorten the operation time, and effectively reduce the radiation exposure of patients and medical staff.

Objective: To explore the safety of ultrasonic osteotome used in posterior cervical laminectomy decompression surgery and its effect on surgical outcome., Methods: A clinical data of 52 patients with ossification of posterior longitudinal ligament of cervical spine (C-OPLL) undergoing posterior cervical laminectomy decompression and fusion (PCLDF) between April 2013 and April 2017 was retrospectively analysed. The patients were divided into two groups according to whether using the ultrasonic osteotome during operation: group A (20 cases, ultrasonic osteotome group) and group B (32 cases, traditional gun-clamp decompression group). There was no significant difference in gender, age, body weight, height, preoperative hemoglobin, and Japanese Orthopedic Association (JOA) score between the two groups ( P >0.05). The operation time, intraoperative blood loss, postoperative drainage volume, hospitalization time, complications, hemoglobin at 1 day after operation, and JOA score at 6 months after operation were recorded and compared between the two groups, and the improvement rate of JOA was calculated., Results: The operation time and intraoperative blood loss in group A were significantly less than those in group B ( P <0.05); there was no significant difference in the drainage volume and hospitalization time between the two groups ( P >0.05). The hemoglobin of group B was slightly higher than that of group A at 1 day after operation, but there was no significant difference between the two groups ( t =-1.260, P =0.214). All the patients were followed up 6-10 months (mean, 7.6 months). No serious complications such as C 5 nerve paralysis, dural tear, infection, epidural hematoma, deep venous thrombosis, pulmonary embolism, transfusion allergy, or shock occurred during and after operation. The JOA scores of the two groups were significant improved at 6 months after operation when compared with preoperative scores ( P <0.05), and there was no significant difference in JOA score and improvement rate between the two groups at 6 months after operation ( P >0.05)., Conclusion: Compared with the traditional gun-clamp decompression, the effectiveness of PCLDF in treatment of C-OPLL by using ultrasonic osteotome is comparable, but the latter can effectively reduce the operation time and blood loss.

Objective: To explore the clinical application value of the spinal robot-assisted surgical system in mild to moderate lumbar spondylolisthesis and evaluate the accuracy of its implantation., Methods: The clinical data of 56 patients with Meyerding grade Ⅰ or Ⅱ lumbar spondylolisthesis who underwent minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) between January 2017 and December 2017 were retrospectively analysed. Among them, 28 cases were preoperatively planned with robotic arm and percutaneous pedicle screw placement according to preoperative planning (group A); the other 28 cases underwent fluoroscopy-guided percutaneous pedicle screw placement (group B). There was no significant difference in gender, age, body mass index, slippage type, Meyerding grade, and surgical segmental distribution between the two groups ( P >0.05). The screw insertion angle was measured by CT, the accuracy of screw implantation was evaluated by Neo's criteria, and the invasion of superior articular process was evaluated by Babu's method., Results: One hundred and twelve screws were implanted in the two groups respectively, 5 screws (4.5%) in group A and 26 screws (23.2%) in group B penetrated the lateral wall of pedicle, and the difference was significant ( χ 2 =9.157, P =0.002); the accuracy of nail implantation was assessed according to Neo's criteria, the results were 107 screws of degree 0, 3 of degree 1, 2 of degree 2 in group A, and 86 screws of degree 0, 16 of degree 1, 6 of degree 2, 4 of degree 3 in group B, showing significant difference between the two groups ( Z =4.915, P =0.031). In group B, 20 (17.9%) screws penetrated the superior articular process, while in group A, 80 screws were removed from the decompression side, and only 3 (3.8%) screws penetrated the superior articular process. According to Babu's method, the degree of screw penetration into the facet joint was assessed. The results were 77 screws of grade 0, 2 of grade 1, 1 of grade 2 in group A, and 92 screws of grade 0, 13 of grade 1, 4 of grade 2, 3 of grade 3 in group B, showing significant difference between the two groups ( Z =7.814, P =0.029). The screw insertion angles of groups A and B were (23.5±6.6)° and (18.1±7.5)° respectively, showing significant difference ( t =3.100, P =0.003)., Conclusion: Compared to fluoroscopy-guided percutaneous pedicle screw placement, robot-assisted percutaneous pedicle screw placement has the advantages such as greater accuracy, lower incidence of screw penetration of the pedicle wall and invasion of the facet joints, and has a better screw insertion angle. Combined with MIS-TLIF, robot-assisted percutaneous pedicle screw placement is an effective minimally invasive treatment for lumbar spondylolisthesis.

Objective: To summarize the progress of larger flexion gap than extension gap in total knee arthro-plasty (TKA)., Methods: The domestic and foreign related literature about larger flexion gap than extension gap in TKA, and its impact factors, biomechanical and kinematic features, and clinical results were summarized., Results: During TKA, to adjust the relations of flexion gap and extension gap is one of the key factors of successful operation. The biomechanical, kinematic, and clinical researches show that properly larger flexion gap than extension gap can improve both the postoperative knee range of motion and the satisfaction of patients, but does not affect the stability of the knee joint. However, there are also contrary findings. So adjustment of flexion gap and extension gap during TKA is still in dispute., Conclusion: Larger flexion gap than extension gap in TKA is a new joint space theory, and long-term clinical efficacy, operation skills, and related complications still need further study.

Objective: To compare the effectiveness between short segmental fixation combined with vertebroplasty (SSF+VP) and short segmental pedicle screw fixation combined with bone graft (SSF+BG) in the treatment of unstable type Kümmell's disease so as to provide a reference for the selection of the surgical method., Methods: Between March 2013 and February 2015, 48 patients with unstable type Kümmell's disease who were in accordance with the inclusive criteria were included in the study. SSF+VP were used in 25 cases (SSF+VP group) and SSF+BG in 23 cases (SSF+BG group). There was no significant difference in gender, age, disease duration, bone mineral density, fracture segment, and preoperative visual analogue scale (VAS), Oswestry disability index (ODI), and kyphotic Cobb angle between 2 groups ( P >0.05). The operation time and complications related to operation were recorded; the effectiveness was evaluated by VAS, ODI, and kyphotic Cobb angle., Results: The operation time was (107.7±18.8) minutes in SSF+VP group and was (113.7±22.4) minutes in SSF+BG group, showing no significant difference between 2 groups ( t =-1.045, P =0.302). Bone cement leakage occurred in 6 cases of SSF+VP group, and incision delayed healing occurred in 1 case of SSF+BG group. All patients achieved bone graft fusion on X-ray films. The bone graft fusion time was (15.1±1.3) weeks in SSF+VP group and (15.7±1.8) weeks in SSF+BG group, showing no significant difference between 2 groups ( t =-1.361, P =0.180). The VAS, ODI, and kyphotic Cobb angle at immediate after operation and at last follow-up were significantly lower than preoperative ones ( P <0.05). The VAS, ODI, and kyphotic Cobb angle had no significant difference between at immediate and at last follow-up in SSF+VP group ( P >0.05). In SSF+BG group, VAS at last follow-up was significantly lower than that at immediate after operation ( P <0.05), but no significant difference was found in kyphotic Cobb angle and ODI ( P >0.05). SSF+VP group was significantly better than SSF+BG group in VAS at immediate after operation ( P <0.05), but SSF+BG group was significantly better than SSF+VP group at last follow-up ( P <0.05). There was no significant difference in kyphotic Cobb angle and ODI between 2 groups at immediate after operation and at last follow-up ( P >0.05)., Conclusion: SSF+BG can achieve satisfactory effectiveness in the treatment of unstable type Kümmell's disease, and it has the advantages of good bony healing, obvious improvement of pain, and low complication incidence when compared with SSF+VP.

Objective: To investigate the clinical efficacy and the indications of posterolateral fusion and pedicle screw short-segment fixation via injured vertebra for treating old thoracolumbar fracture combined with kyphosis in elderly patients., Methods: Between January 2012 and December 2014, 24 patients with old thoracolumbar fracture and kyphosis received posterolateral fusion and pedicle screw short-segment fixation via injured vertebra. Of 24 cases, 8 were male and 16 were female with an average age of 66.3 years (range, 56-79 years). The mean disease course was 17.5 months (range, 5-36 months). There were 13 cases of osteoporosis, 9 cases of osteopenia, and 2 cases of normal bone. The visual analogue scale (VAS) was 6.53±0.95, and Oswestry disability index (ODI) was 52.63%±5.74% preoperatively. The thoracolumbar kyphosis located at T 10 to L 2 , and the kyphotic Cobb angle was (28.79±5.04)° before operation., Results: The operation was completed successfully without related complications. The operative time was 1.2-2.3 hours (mean, 1.6 hours), and intraoperative blood loss was 80-210 mL (mean, 158 mL). No nerve injury occurred. Poor healing of incision was observed in 1 patient with diabetes, and primary healing of incision was obtained in the other patients. Nineteen patients were followed up 6-30 months (mean, 14.4 months), and there were 2 deaths. Pain relief and function recovery were obtained in 19 patients after operation. The VAS score and ODI were significantly decreased to 2.4±0.7 and 32.14%±5.12% at last follow-up ( t =8.542, P =0.000; t =9.826, P =0.000). The kyphotic Cobb angle was significantly decreased to (21.23±4.30)° at immediate after operation ( P <0.05) and to (23.68±4.35)° at last follow-up ( P <0.05), but no significant difference was found between at immediate and last follow-up ( P >0.05). No loosening or breakage of internal fixation was observed during follow-up., Conclusions: Posterolateral fusion and pedicle screw short-segment fixation via injured vertebra is a safe and effective treatment for elderly patients with old thoracolumbar fracture combined with kyphosis (Cobb angle less than 40°).

Objective: To observe the clinical effect of dexmedetomidine on patients during the extubation in general anesthesia.
, Methods: A total of 90 patients scheduled for general anesthesia were divided into 3 groups (n=30): A dexmedetomidine group (DEX group), a midazolam group (MID group), and a control group(C group). Anesthesia drugs were stopped 10 minutes before the end of the operation. 
At the same time, the patients in the DEX group were given dexmedetomidine at the rate of 
1 g/(kg.h) for 10 min by vein first, which was continuously pumped at the rate of 0.3 g/(kg.h) for 20 min after the operation. The patients in the MID group were given midazolamin at 0.5 mg/kg for 60 s by vein first, which was continuously pumped at the rate of the 0.04 mg/(kg.h) for 20 min after the operation. The patients in the C group were not given any drug. Awakening time and extubation time after the operation were recorded. Ramsay scores, heart rate, mean arterial blood pressure, respiratory rate, and SpO₂were recorded at time of extubation, 10 min or 1 h after extubation. Chills, nausea, vomiting and other side effects after the operation were recorded.
, Results: Awakening and extubation time were not affected in the DEX group, while delayed recovery occurred in the MID group (P<0.05). Compared with the C group, patients in the DEX and MID groups gained better sedative effect, with 2-4 Ramsay scores (P<0.05). The blood pressure and heart rate were steady in the DEX and MID groups, while inhibition of respiration appeared in the MID group.
, Conclusion: Dexmedetomidine can provide an effective sedation for the patients without affecting the awakening and extubation time. The hemodynamics could be stably maintained by using dexmedetomidine in patients during the extubation in general anesthesia.

Objective: To investigate the incidence of C5 nerve root palsy after multi-segmental cervical decompression through different approaches., Methods: This study was conducted among 375 patients undergoing multi-segmental cervical decompression in anterior corpectomy and fusion fixation, anterior cervical corpectomy and fusion fixation + posterior decompression and fusion fixation, posterior cervical laminectomy decompression, fusion and internal fixation, and posterior laminoplasty and fusion groups. The exclusion criteria included lack of follow-up data, spinal cord injury preventing preoperative or postoperative motor testing, or surgery not involving the C5 level. The incidence of C5 palsy was determined and the potential risk factors C5 palsy were analyzed including age, sex, revision surgery, preoperative weakness, diabetes, smoking, number of levels decompressed, and a history of previous upper extremity surgery., Results: Of the 375 patients, 60 patients were excluded and the data of 315 patients were analyzed, including 146 women and 169 men with a mean age of 57.7 years (range 39-72 years). The overall incidence of C5 nerve palsy was 6.03% (19/315) in these patients; in the subgroups receiving different surgeries, the incidence was 8.62% in the cervical road laminectomy and fusion fixation group, 7.79% in the anterior cervical corpectomy and fusion fixation + posterior decompression and fusion and internal fixation, 4.68% in the anterior corpectomy and fusion fixation group, and 3.85% in the posterior laminoplasty and fusion group. No significant difference was found in the incidences among the subgroups, but men were more likely than women to develop cervical nerve root palsy (8.28% vs 3.42%, P<0.05)., Conclusion: The overall incidence of C5 nerve palsy following postoperative cervical spinal decompression was 6.03% in our cohort. The incidence of C5 nerve palsy did not differ significantly following different cervical decompression surgeries, but the incidence was the highest in the posterior cervical laminectomy and fusion and internal fixation group.

Objective: To explore the effectiveness of anterior cervical plate internal fixation in the treatment of unstable Hangman fracture., Methods: Between May 2006 and May 2010, 42 patients with unstable Hangman fracture were treated by anterior cervical plate internal fixation. There were 30 males and 12 females with an average age of 36.5 years (range, 22-64 years). According to the Levine-Edwards classification, 25 cases were rated as type II, 15 cases as type II A, and 2 cases as type III. Eight patients had spinal cord injury. The average interval between injury and operation was 5 days (range, 3-14 days). The X-ray, CT, and MRI were done pre- and post-operatively to evaluate the cervical physiological curvature, the intervertebral disc height of C2, 3, the fracture-healing, and bone fusion. The effectiveness was evaluated using visual analogue scale (VAS) for occipitocervical pain, Neck Disability Index (NDI) for cervical spine function, and the Japanese Orthopaedic Association (JOA) score for neurological functional recovery., Results: All incisions healed by first intention. No neurological deterioration or internal fixation failure was observed. All of the patients were followed up 2-5 years (mean, 3.5 years). The complications were dysdipsia in 3 cases and dysphagia in 4 cases, which alleviated spontaneously after 1 week. All the patients were almost free from occipitocervical pain and the limited cervical spine motion. Neurological function was improved in 8 cases of spinal cord injury, and complete decompression was observed in 6 cases who had spinal cord compression. The bone fusion was observed at 6.5 months on average (range, 6-8 months); the mean fracture-healing time was 10.5 months (range, 9-12 months). The VAS, NDI, and JOA scores were significantly improved at 3 months after operation and last follow-up when compared with preoperative scores (P < 0.05), significant improvement scores were achieved at last follow-up when compared with the scores at 3 months (P < 0.05). The intervertebral disc height of C2, 3, the reconstructed curvature and stability of the cervical spine, and the spine movement were good., Conclusion: The method of anterior cervical plate internal fixation can achieve satisfactory reduction and fusion, less complications, negligible impact on the cervical movement. So it is an ideal method to treat unstable Hangman fracture.