长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

预先心理应激对干舱模拟快速上浮脱险大鼠应激反应的作用

Objective To observe the effects of psychological pretreatment on the stress reaction of simulated fast buoyancy ascent escape in rats. Methods Forty healthy rats were randomly divided into 4 groups:the control group, the psychological stress group, the fast compression and decompression group, and the psychological stress pretreatment plus fast compression and decompression group. By developing the fast buoyancy ascent escape rat model with fast compression and decompression in a closed cabin, the effects of psychological pretreatment on the stress reaction were observed in the course of ascent. Results Hear t rate of the animals in the psychological pretreatment stress group was significantly higher than that in the control group (P＜0. 05), and the expression of serum TNF-α was significantly lower than that in the control group (P ＜ 0.05 ). Conclusions Psychological factor seemed to have positive effects on the stress reaction of the simulated fast buoyancy ascent escape in rats.     

长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

不同镇痛方式对下肢骨折手术患者应激反应及焦虑状况的影响

Objective To observe the effect of different analgesic methods including patient controlled epidural analgesia (PCEA) and patient controlled intravenous analgesia (PCIA) on stress response and anxiety in surgical patients with lower limb fracture. Methods A total of 120 surgical patients with lower limb fractures were employed and divided randomly into Groups PCEA, PCIA and C (40per group). All patients were anaesthetized by using combined spinal-epidural anesthesia. After operation, PCEA and PCIA were applied in the patients of Groups PCEA and PCIA, respectively. No analgesic method was employed in the Group C. The dynamic indices including mean blood press (MAP) and heart rate (HR), blood serum cortisol (COR) and blood sugar (BS) were measured at different time points,ie, T0 ( pre-anesthesia), T1 ( the end of the operation), T2 (24 hours after operation) and T3 (48 hours after operation). The visual analogue pain score was conducted at time points of T1, T2 and T3. The measurement of anxiety score was done at pre-operation and at days 1 and 7 after operation. Results There were no significant changes in HR and MAP of Groups PCEA and PCIA (P＞0.05, compared with T0) at every time point after operation. Whereas, HR and MAP of Group C were increased at time points of T1 and T2 (P ＜ 0.05, compared with T0 ), with statistical difference compared with Groups PCEA and PCIA at the same time points (P ＜ 0.05 ). VAS in Group PCEA was lower than that in Group PCIA at time points of T2 and T3 ( P ＜ 0.05). Meanwhile, VAS in Groups PCEA and PCIA was lower than that in Group C (P＜0. 05). COR and BS in Group PCEA were significant lower than those in group PCIA at time points of T2 and T3 (P ＜ 0. 05 ). Meanwhile, COR and BS in Groups PCEA and PCIA was lower than that in Group C (P＜0.05 or ＜0.01 ). Moreover, the changes were more significant in Group PCIA than that in Group PCEA (P ＜ 0. 05 ). The anxiety score in Groups PCEA and PCIA was lower than that in Group C (P ＜ 0.05). Conclusions Two analgesic methods of PCEA and PCIA can provide safe and effective postoperative analgesia and attenuate the stress response and anxiety in surgical patients with lower limb fracture. Meanwhile, PCEA takes more advantages than PCIA.     

长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

长期视远剥夺对人眼集合近点和调节近点的影响

Objective To study effects of sustained deprivation of far sight on human near point of convergence (NPC) and near point of accommodation (NPA). Methods Eight subjects were divided into two groups by age (group A ≥30 years old; group B<30 years old). All subjects had worked in the enclosed laboratory, unable to see the outside for 75 days. NPC and NPA were measured every 15 days. Results NPC values of both groups all increased when time elapsed. NPC of group A measured in the 75th day and NPC of group B in the 30th day all had statistical differences, when compared with the base NPC values measured in the 15th day (P<0.05). And NPC value of group B measured in the 45th, 60th and 75th days increased markedly, when compared with that of the 15th day (P<0.01 . However, statistical analysis showed that no significant difference could be seen in NPA values of the two groups (P>0.05). Conclusions Sustained deprivation of far sight could induce an increase in NPC values to various degreeal, but effects on NPA were not obvious, as noted in our experiment.     

Effects of hyperbaric oxygen on TF、TNF-α in the rabbit model of steroid-induced avascular osteonecrosis of femoral head

Objective To investigate dynamic changes in serum TF and TNF-α in the rabbit model of steroid-induced avascular osteonecrosis of femoral head ( SANFH) and also to explore the mechanism of SANFH, as well as effects of hyperbaric oxygen ( HBO) on SANFH. Methods Seventy-eight New Zealand male rabbits were randomly divided into 3 groups:the normal control (group N) (7 animals), the model group (group M) (41 animals) and the HBO group (group H) (30 animals). The model group was subdivided into the immediate model group (the M0 group) (10 animals), the two-week model group (the M2 group) (10 animals), the four-week model group (the M4 group) (10 animals) and the six-week model group (the M6 group) (11 animals). The HBO group was further divided into the 2-week HBO therapy group (HBO2) (7 animals), the 4-week HBO therapy group (HBO4) (11 animals) and the 6-week HBO therapy group (HBO6) (12 animals). Through injection of endotoxin and methyl-prednisolone, rabbits in the group HBO2, HBO4 and HBO6 received HBO therapy 1 hour daily from the second day of the experiment. The durations of HBO therapy were 2 weeks ( HBO2), and 4 weeks respectively. The animals were sacrificed after blood samples were taken at respective blood collection time. Then, levels of TF, TNF-α in the serum were measured and the histological changes in the femoral heads were observed. Results Levels of TF and TNF-α in group M0 increased significantly, when compared with those of group N (P ＜0. 05 or P ＜0.01), while for the HBO subgroups the expression of TF and TNF-α measured at the same time points all decreased, when compared with that of the model subgroups (P＜0. 05 or P ＜0.01). To elaborate, TF levels in group M2 and M4 were much higher than those in group HBO2 and HBO4 ( P＜0. 01 ). TF level in group M6 was higher than that in group HB06 ( P ＜ 0.05). TNF-α in group M0 also increased significantly, when compared with that in group N( P ＜0.01). TNF-α levels in group M2 and M6 were also much higher than those in group HBO2 and HBO6 ( both P ＜0. 01 ). TNF-α in group M4 was higher than that in group HBO4 (P＜0.01). Histological examination revealed that tissues of the femoral heads in group N were normal, osteonecrosis and thrombus could be noted in group M2 and M4, hyperplasia fibrosis could be found in group M6, and osteonecrosis in HBO2 and HB04 groups seemed less severer than that in M2 and M4 groups, no thrombi in HBO2, HBO4 groups were noted, and growth of new bones were detected in HBO4 and HBO6. Conclusions The levels of TF and TNF-α levels increased in the rabbit model of SANFH, inducing blood coagulation. Thrombosis at the femoral heads was one of the causes of SANFH. HBO therapy could inhibit the release of TF and TNF-α, thus improving the abnormality of blood coagulation and enhancing treatment of osteonecrosis.     

神经行为评价系统在飞行员脑功能评定中的应用研究

Objective To explore the application of neurobehavioral evaluation system-C3(NES-C3) for pilot's cerebral function (CF) evaluation. Methods The characters of CF under interference of simulated jet engine noise and neurobehavioral ability index (NAI) were investigated in 45 military pilots [(27.6±2.5) yr] (as pilot group) and in 45 college students [(27.5±2.6) yr] (as control group) by NES-C3. The variance of profile of mood statues (POMS) scales, (including tension-anxiety, angry-hostility, exhausted-inertia, gloom-depressed, powerful-restless and stumblepuzzle) and NAI (including memory scanning, digital scanning, visual simple reaction time, visual complex reaction time, pursuit aiming, and consecutive performance) were compared respectively.Results With or without interference of noise, the score of "powerful-restless" in pilot group was higher than that in control group (t=9.74, 12.52, P＜0.05), and the score of tension-anxiety in control group was higher than that in pilot group (t= 10. 46, 14.25, P＜0. 05). When noise was applied, the score of POMS in control group was significantly increased (t=2. 85-6. 33, P＜0. 05) but in pilot group only "tension-anxiety" and "powerful-restless" were significantly increased (t = 4. 12,5.92, P＜0.05). The score of "tension-anxiety" in control group was higher than that in pilot group.Four items of NAI in pilot group were significantly higher than those in control group (t= 2 91-10.55, P＜0. 05). There were no noised induced significant NAI changes in pilot group but in control group. They were not only lower than that in the state without noise interference (t-5.24-29.24,P＜0. 05) but also lower than that in pilot group (t=4. 07-28. 41, P＜0. 05). Conclusions NES-C3 is a useful tool for the identification of pilot's CF.     

人工富氧环境改善急进高原人员睡眠效果的研究

Objective To study the effects of the artificial oxygen-enriched environment (is called "oxygen-enriched room" in short) on sleep efficiency of the people who participate in the mission on plateau with hurry-up entry,and to investigate the anti-hypoxia effect of oxygen-enriched room to plateau acclimatization. Methods Eighteen subjects were randomly and averagety allocated into plain group,oxygen-enriched group and hypoxia group.Only the later two groups were dispatched to plateau by air.Molecular sieve oxygenerator was used to supply the room with oxygen on 3500 m plateau.The oxygen-enriched group and hypoxia group got into the oxygen-enriched rooms and normal rooms respectively at 22 o' clock and took rest till to 9 o' clock next morning.The changes of heart rate (HR) and the saturation of blood oxygen (SaO2) of three groups were recorded and compared between the states of with and without oxygen enrichment.The subjects were monitored by sleep respiration recording and analysis system. Results ①The SaO2 of the oxygen-enriched group was 92.3%±1.0%,and it was significant higher than the state before oxygen enrichment (82.9%±4.2%) and than that of hypoxia group (79.3%±5.9%,P<0.01),but lower than that of plain group (97.3%±0.8%,P<0.05).②There were less deep sleep and more slight sleep in hypoxia group and oxygen-enriched group than in plain group.The hypopnea and apnea hypopnea index (AHI) of plain group was significant lower than that of hypoxia group and oxygen-enriched group (P<0.05).The AHI of the oxygen-enriched group was 28.1±11.9,and it was significant lower than that of hypoxia group (53.2±23.4)(P<0.05).③The normalized low-frequency (Ln) and the ratio of low-frequency to high-frequency (LF/HF) measured in sleep was respectively 89.3±2.9 and 6.4±1.4 in oxygen-enriched group comparing to 90.2±1.8 and 9.9±1.9 in hypoxia group but without statistical difference.The corresponding Ln and LF/HF of plain group was 85.8±2.9 and 6.4±1.4 respectively,significantly higher than those of other two groups (P<0.05).Plain group also showed higher normalized high-frequency than others(P<0.05). Conclusions Oxygen-enriched environment can effectively improve the sleep quality but significantly change heart rate variation (HRV) of the people who participate in the mission with hurry-up entry to plateau.Further studies are still needed to reveal the quantitative effectiveness of oxygen-enriched room to plateau acclimatization.     

寰枢椎椎弓根钉固定治疗伸直型齿状突骨折合并寰枢关节半脱位

Objective To explore the clinical outcome of atlantoaxial pedicle screw instrument in treatment of extension-type odontoid fracture combined with aflantoaxial subluxation. Methods From December 2002 to December 2006, seven patients with extension-type odontoid fracture combined with at-lantoaxial subluxation were reduced and fixed with atlantoaxial pedicle screw instrument of Vertex system under general anesthesia. There were five males and two females, at mean age of 39.2 years (range 21-59 years). All odontoid fractures were fresh type Aderson Ⅱ. JOA scores of spinal core function was 8.6-14.9 (average 10.7) preoperatively. The X-ray examination, CT scanning and skull traction were performed in all patients preoperatively. Results There found no severe complications such as injuries of vertebral artery, nerve root and spinal cord postoperatively. All patients obtained complete reduction and healing of the fracture and dislocation. The mean off-bed time was four days (3-6 days) after opera-tion. A follow-up for 12-36 months (average 22 months) in all patients showed that the clinical symptom was improved significantly six months postoperatively and that all screws were in proper position verified by X-ray and CT scanning. All patients obtained solid bony union on radiographs, with no loosing or breakage of instrument. The postoperative JOA scores was 13.5-16.9 (average 15.8). Conclusions Allantoaxial pedicle screw fixation has advantages of intraoperative reduction, reliable fixation and high fusion rate and can be used as an effective method for extension-type odontoid fracture combined with at-lantoaxial subluxation.     

寰枢椎椎弓根钉固定治疗伸直型齿状突骨折合并寰枢关节半脱位

Objective To explore the clinical outcome of atlantoaxial pedicle screw instrument in treatment of extension-type odontoid fracture combined with aflantoaxial subluxation. Methods From December 2002 to December 2006, seven patients with extension-type odontoid fracture combined with at-lantoaxial subluxation were reduced and fixed with atlantoaxial pedicle screw instrument of Vertex system under general anesthesia. There were five males and two females, at mean age of 39.2 years (range 21-59 years). All odontoid fractures were fresh type Aderson Ⅱ. JOA scores of spinal core function was 8.6-14.9 (average 10.7) preoperatively. The X-ray examination, CT scanning and skull traction were performed in all patients preoperatively. Results There found no severe complications such as injuries of vertebral artery, nerve root and spinal cord postoperatively. All patients obtained complete reduction and healing of the fracture and dislocation. The mean off-bed time was four days (3-6 days) after opera-tion. A follow-up for 12-36 months (average 22 months) in all patients showed that the clinical symptom was improved significantly six months postoperatively and that all screws were in proper position verified by X-ray and CT scanning. All patients obtained solid bony union on radiographs, with no loosing or breakage of instrument. The postoperative JOA scores was 13.5-16.9 (average 15.8). Conclusions Allantoaxial pedicle screw fixation has advantages of intraoperative reduction, reliable fixation and high fusion rate and can be used as an effective method for extension-type odontoid fracture combined with at-lantoaxial subluxation.     

Tendon Stem Cells and Piatelet-Rich Plasma

Acute and chronic tendon injuries(i.e.tendinopathy) are common,yet current treatments cannot restore normal structure and function to injured tendons.This problem mainly stems from our incomplete understanding of tendon cell properties and responses to biomechanical and biochemical environments surrounding the cells.However,significant progress has been made in recent years on two fronts.The first is the new discovery that tendons contain a population of multi-potent tendon stem cells(TSCs).The second is the wide application of platelet-rich plasma(PRP) in orthopaedics and sports medicine to treat injured tendons.This mini-review aims to discuss the studies on TSCs,with a focus on their differential properties with respect to tenocytes and their differential mechano-responses when subjected to small and large mechanical loading conditions.In light of the critical importance of the safety and efficacy of PRP treatment in clinic,basic scientific research related to PRP effects on TSCs,particularly on their differentiation,is also presented.Finally,the urgent need for rigorous basic scientific research to justify PRP applications in clinic settings is proposed.     

寰枢椎椎弓根钉固定治疗伸直型齿状突骨折合并寰枢关节半脱位

Objective To explore the clinical outcome of atlantoaxial pedicle screw instrument in treatment of extension-type odontoid fracture combined with aflantoaxial subluxation. Methods From December 2002 to December 2006, seven patients with extension-type odontoid fracture combined with at-lantoaxial subluxation were reduced and fixed with atlantoaxial pedicle screw instrument of Vertex system under general anesthesia. There were five males and two females, at mean age of 39.2 years (range 21-59 years). All odontoid fractures were fresh type Aderson Ⅱ. JOA scores of spinal core function was 8.6-14.9 (average 10.7) preoperatively. The X-ray examination, CT scanning and skull traction were performed in all patients preoperatively. Results There found no severe complications such as injuries of vertebral artery, nerve root and spinal cord postoperatively. All patients obtained complete reduction and healing of the fracture and dislocation. The mean off-bed time was four days (3-6 days) after opera-tion. A follow-up for 12-36 months (average 22 months) in all patients showed that the clinical symptom was improved significantly six months postoperatively and that all screws were in proper position verified by X-ray and CT scanning. All patients obtained solid bony union on radiographs, with no loosing or breakage of instrument. The postoperative JOA scores was 13.5-16.9 (average 15.8). Conclusions Allantoaxial pedicle screw fixation has advantages of intraoperative reduction, reliable fixation and high fusion rate and can be used as an effective method for extension-type odontoid fracture combined with at-lantoaxial subluxation.     

寰枢椎椎弓根钉固定治疗伸直型齿状突骨折合并寰枢关节半脱位

Objective To explore the clinical outcome of atlantoaxial pedicle screw instrument in treatment of extension-type odontoid fracture combined with aflantoaxial subluxation. Methods From December 2002 to December 2006, seven patients with extension-type odontoid fracture combined with at-lantoaxial subluxation were reduced and fixed with atlantoaxial pedicle screw instrument of Vertex system under general anesthesia. There were five males and two females, at mean age of 39.2 years (range 21-59 years). All odontoid fractures were fresh type Aderson Ⅱ. JOA scores of spinal core function was 8.6-14.9 (average 10.7) preoperatively. The X-ray examination, CT scanning and skull traction were performed in all patients preoperatively. Results There found no severe complications such as injuries of vertebral artery, nerve root and spinal cord postoperatively. All patients obtained complete reduction and healing of the fracture and dislocation. The mean off-bed time was four days (3-6 days) after opera-tion. A follow-up for 12-36 months (average 22 months) in all patients showed that the clinical symptom was improved significantly six months postoperatively and that all screws were in proper position verified by X-ray and CT scanning. All patients obtained solid bony union on radiographs, with no loosing or breakage of instrument. The postoperative JOA scores was 13.5-16.9 (average 15.8). Conclusions Allantoaxial pedicle screw fixation has advantages of intraoperative reduction, reliable fixation and high fusion rate and can be used as an effective method for extension-type odontoid fracture combined with at-lantoaxial subluxation.