Objective To study the feasibility and clinical results of C2, 3 pedicle-lateral mass plate fixation in the treatment of unstable Hangman's fractures. Methods From March 1999 to July 2005, 25 cases of unstable Hangman's fracture were treated surgically using the C2, 3 pedicle-lateral mass plate. All the cases were followed up for the healing of bone and function of the cervical vertebrate. Results The average follow-up period was 38 months. Twenty-three cases had a perfect reduction. Three cases had kyphosis deformity. There were no other complications related to the operation. AH the cases had a perfect early fusion of the C2 pedicle isthmus and long-term stability of C2, 3 intervertebral space. The clinic results were good. Conclusion Since the C2, 3 pedicle-lateral mass fixation can provide immediate reduction and satisfactory biomechanical stability, it is a good device for unstable Hangman s fractures.

Objective To evaluate the clinical effect and application value of internal fixation of Magerl combined with Brooks technique for atlantoaxial instability. Methods A total of 18 patients with atlantoaxial instability, reducible atlantoaxial dislocation with reduction after traction and irreducible atlantoaxial dislocation with traction reduction after anterior laxation were treated with internal fixation of Magerl combined with Brooks technique using autologous bone grafts. Results The patients were followed up for an average 18 months (6-36 months). Screw was probably cut into the vertebral artery in one case. The guide needle was cut into the pharynx due to incorrectly penetrating the C 1 anterior arch of atlas for 3.5 cm in one case but no early complications such as spinal cord injury and local infection occurred. The spinal cord function improvement was marked in 3 cases, good in 9, mild in 4 but unchanged in 2. No case got worse. There were no loosening or break of the screw and cable. Conclusions Combined fixation of Magerl and Brooks techniques reaches three-point fixation and improves the reduction effect. It is necessary to use the combined fixation with best biomechanical stability for atlantoaxial dislocation patient with reduction or near reduction if the structure of the posterior arch of C 1,2 is intact.

[Objective]To investigate the method of anterior transsternal approach for the patients with upper thoracic spine diseases and the clinic results.[Method]Six cases upper thoracic spinal diseases,1 case of C7/T1 grade V dislocation,1 case of T1、2 TB,2 cases of upper thoracic tumor,1 case of T2 fracture and 1 case of T2、3 disc prolapse,were treated with the anterior transsternal approach operation since Oct.2001.The lesions areas were exposed via partial or complete sternotomy.The relative articles were reviewed.[Result]The average follow-up was 12.4 months(range from 6 to 22 months,except the died one).The case of C7/T1 grade V dislocation died of respiratory tract obstruction and one case of malignant schwannoma recurred 6 months post-operation.Good results were obtained in the other 4 cases.No operative complication happened in all cases.[Conclusion]While the transthoracic lateral approach cannot expose the upper thoracic spine clearly,the anterior cervical approach cannot expose the T2、3 clearly also.The anterior transsternal approach can provide a safe access to the lesions located on the upper thoracic spine above T4.

Objective To eveluate the result of the use of prosthetic disc nucleus (PDN) for treatment of degenerative disc diseases in the lumbar spine. Methods Twenty-two patients with degenerative disc diseases were treated with PDN replacement after the removal of the degenerated intervertebral disc. Results The patients were followed-up for an average 12 months (4-18 months). Both lumbago and leg pain disappeared in all the 22 patients who resumed their work and normal life one month after the operation. PDN translocation was found in 2 out of 10 patients in the early period, but no PDN translocation was found in the remaining 12 patients in the later period. Conclusion PDN could restore disc height and flexibility after nucleotomy. Artificial nucleus replacement was a good option for the treatment of degenerative lumbar disc disease.

Objective To summarize the experience of preventing infection in atlanto-axial operations via transoropharyngeal approach. Methods The methods and experiences of prevention of infection in 80 cases of atlanto-axial dislocation operated on via transoropharyngeal approach were retrospectively summarized and analyzed. Result There was no infection in all the 80 cases. Conclusion As long as preventive measures were perfectly taken, the post-operative infection could be effectively prevented and the transoropharyngeal operation would be safe.

Objective To evaluate the clinical results of subtotal vertebrectomy of the axis for spinal canal decompression by transoral anterior approach in the treatment of atlanto-axial dislocation with spinal cord compression. Method fifteen cases of atlanto-axial dislocation with spinal cord compression caused by congenital deformity or trauma were subjected to subtotal vertebrectomy of the axis via transoral anterior approach . Results After an average follow-up of 20 months, curative effect was evaluated according to Symon and Lavender. Vertebral canal vector diameters in MRI were measured. The total clinical effective rate was 100%, and the remarkable effective rate reached 60%. The average improvement rate of vertebral canal decompression was 79.8%. No sign of spinal cord and arteries injury and infection were observed. Conclusion Subtotal vertebrectomy of the axis via transoral anterior approach is proved to be feasible to treat cervical spinal cord compression on C 2 vertebra level.

0.05). The ROM of flexion-extension, lateral bending and axial rotation of these two groups was smaller than that of the other three fixators(P0.05). Conclusion Experimentally, the effect of TARP was equal to that of Magerl+Brooks, but it was proved to be more stable than the other three clinically widely used atlantoaxial fixators: Magerl, Brooks and anterior transarticular screw fixation through C 2 vertebral body. TARP's C 1 and C 2 screws were strong enough for atlanto-axial arthrodesis. TARP's biomechanical performance was excellent.

ObjectiveTo evaluate biomechanical properties of transoralpharyngeal atlantoaxial reduction plate (TARP) prepared from magnesium alloy and titanium alloy for the atlantoaxial dislocation by using three-dimensional finite element analysis and to exam the feasibility of using magnesium alloy for preparation of TARP system so as to provide a theoretical basis for clinical surgery.MethodsA patient with typical atlantoaxial fracture dislocation was involved in the study,and received thin CT scan with clinically used titanium alloy TARP system for obtaining DICOM image data.Three-dimensional finite element analysis software was imported to simulate magnesium alloy and titanium alloy TARP systems for reduction and fixation.Then,stress changes of the atlas,axis,internal fixators and C2/3 zygapophysial joints were determined with three-dimensional finite element analysis and analyzed statistically.Results ( 1 ) The finite element model of atlantoaxial dislocation reduction and fixation had lifelike outline and good geometric similarity.There were 53 586 nodes and 180 784 units.(2) During the simulation of head in neutral position,the stress concentration region was C2/3 zygapophysial joints followed by the anterior arch,posterior arch and lateral mass of atlas respectively,and C2 vertebral arch again.( 3 )Magnesium alloy and titanium alloy TARP systems showed significant difference in stress distribution (P ＜0.05).Conclusions(1)The atlantoaxial model established according to its structure information on CT can be used for biomechanical experiments.(2) For the treatment of atlantoaxial dislocation using the existing titanium TARP system,maintaining the integrity of anterior and posterior arch of atlas and confirming the bone fusion in lateral mass can better keep the stability of the atlantoaxis.After atlantoaxial fusion,the increased stress of the zygapophysial joints of the adjacent segments accelerates structural degeneration,which should be closely followed up.( 3 ) Magnesium alloy TARP system for fixation and reduction shows the fall in peak value of the stress concentration region,and improvement of the uniformity of stress distribution as compared with titanium alloy TARP.

53cases of patients were treated a variety of internal fixation apparatuses, including the occipito-cervical CD (OCCD), the Cervifix, Apofix, Orion or AO cervical plates and screws, and were followed-up for 6 to 23 months (average 12 months). Good osteal fusion was obtained in 52 cases of patients after the internal fixation. Absorption of grafted bone was observed in one patient who had the atla-axis fusion with the Apofix fixation. Secondary operation of decompression was done in one patient who had the occipito-cervical fusion with the fixation of OCCD without removal of the postenor arch of the atlas. According to the JOA criterion for spinal function, the improvement rates were 14.3% to 100% (average 80%).

Objective: To observe the impact of mind-regulating acupuncture plus donepezil on the cognitive ability, mean cerebral blood flow velocity, event-related potential P300, and activities of daily living (ADL) in the aged patients with Alzheimer disease (AD).Methods: Sixty senile AD patients were divided into a treatment group and a control group following the envelope method for random allocation, with 30 cases in each group. Based on the conventional treatment of the internal medicine, the control group received oral donepezil, and the treatment group received oral donepezil plus mind-regulating acupuncture. After 4-week treatment, the two groups were evaluated by the mini-mental state examination (MMSE), Alzheimer disease assessment scale-cognitive part (ADAS-Cog), and ADL; changes in P300 and the mean cerebral blood flow velocity were also observed.Results: Before treatment, there were no significant differences in the scores of MMSE, ADAS-Cog, or ADL between the two groups (P>0.05). The MMSE score increased after treatment in both groups and was notably higher in the treatment group than in the control group, showing intra-group and inter-group statistical significance (P<0.05). After treatment, the ADAS-Cog and ADL scores dropped in both groups and were markedly lower in the treatment group than in the control group, also showing intra-group and inter-group statistical significance (P<0.05). Compared with the same group before treatment, the latency of P300 was shortened and the amplitude was extended in both groups, all with statistical significance (P<0.05); the latency was shorter and the amplitude was larger in the treatment group than in the control group after treatment, presenting significant between-group differences (P<0.05). The mean blood flow velocity accelerated after the intervention in both groups, and the differences were statistically significant (P<0.05); the improvement in the treatment group was more notable than that in the control group (P<0.05).Conclusion: Mind-regulating acupuncture plus donepezil can regulate the latency and amplitude of P300, increase cerebral blood flow, and improve the learning and memory abilities of AD patients.