Objective To study the effect of the expansive open-door laminoplasty on the three-dimensional motion and stiffness of the cervical spine. Methods 55 cases after open-door laminoplasty of cervical spine due to myelopathy were follow-up for an average of 35.9 months. Cervical axial symptoms, neural functionality (JOA scoring system) and pre- and post-surgery dynamic cervical spine lateral X-ray films were evaluated. The Three-dimensional Motion and Stiffness of the Cervical Spine of Human Body Measuring Equipment was used in 12 post-operative open door laminoplasty cases and 10 pre-operative cases to measure the active and passive range of motion(ROM), load-displacement relationship, stiffness of cervical spine and torque caused by the isometric contraction of the extensors and flexors of the cervical spine. Results The average rate of improvement was 66. 2%. The excellent and good rate was 78.2%. The number of cases with distinct or severe cervical axial symptoms increased after the surgery ( P ＜ 0. O1 ) . The patients who have severe axial symptoms tend to have less curved cervical spine (P ＜ 0. 01 ) . There was no significant statistic difference between the severity of post-surgery cervical axial symptoms and JOA improvement level (P ＞ 0. 05). The active and passive ROM of extension, rotation and lateral bending of cervical spine were decreased after the surgery ( P ＜ 0. 05), and the main affection was on the middle and lower part of the cervical spine. The load-displacement figure of cervical spine can fit into an exponential equation T= b0eb1θ. In each direction, the lateral bending had the strongest stiffness, then the extension and flexion. The stiffness of rotation was the weakest. The stiffness of cervical spine of the post-surgery group was stronger than that of the contrast group. Conclusion The open-door laminoplasty of cervical spine damages the static mechanic balance on the sagittal plane and decreases the ROM and the flexibility of cervical spine. The curvature of the cervical spine is related to the severity of the axial symptoms and seems not to be related to the JOA score improvement.

Objective To investigate the radiographic features and surgical approach of severe fixed cervical kyphosis.Methods Seventeen cases of severe fixed cervical kyphosis from January 2007 to January 2012 were studied retrospectively.There were 8 males and 9 females,with an average age of 49.7 years.The etiologies were 3 cases of infection,3 cases of degeneration,3 cases of neurofibromatosis,3 cases of prior laminectomy,2 cases of idiopathic,2 cases of trauma and 1 case of neuromuscular disease.The average length of kyphosis was 4.3 ± 1.2 segments.All patients complained of severe neck pain (visual analogue scale,VAS,7.6±1.5) or progressive cervical kyphosis.There were 4 cases with myelopathy,2 with radiculopathy,3 with difficulty of forward gaze and 1 with difficulty of swallowing.All patients were underwent dynamic flexion-extension radiographs and traction views.CT scans were carried out to identify the sites of fixed kyphosis.Continuous traction was performed after general anesthesia,and the surgical approach was decided according to spinal cord compression,length of kyphosis and the cause of fixed kyphosis.Surgical outcomes were assessed in terms of correction of Cobb angle and Odom criteria.Results All patients were followed-up for 2 to 5 years.According to the CT scans,the sites of fixed kyphosis were identified:anterior bony ankylosis in 7 cases,posterior in 6 cases and both anterior and posterior in 4 cases.The surgical approach were as following:anterior only in 4 cases,posterior only in 2 cases,anterior-posterior in 5 cases,posterior-anterior in 3 cases,anterior-posterior-anterior in 1 case and posterior-anterior-posterior in 2 cases.The Cobb angle was corrected from 49.3°± 14.6° preoperation to 2.1 °±6.8° at the latest follow-up,with an average correction of 47.2°.According to Odom criteria,there were 7 excellent outcome,8 good,2 fair and none poor outcome.Revision surgery was performed in 1 case due to proximal junctional kyphosis.At the latest follow-up,bony fusion was found in all patients.Conclusion CT scan is helpful in identifying the cause of fixed kyphosis.The surgical approach of fixed cervical kyphosis is decided by spinal cord compression,length of kyphosis and cause of fixed kyphosis.Anterior approach is suitable for anterior ankylosis,posterior approach for posterior ankylosis,combined approach for both anterior and posterior ankylosis.

Objective To determine the biomechanical variation in full-length femoral stress pat-tern and periprosthetic femoral stress distribution after implantation either with Charnley Elite cemented prostlesis or Summit proximal porous cementless femoral prosthesis. Methods Three-dimensional finite element models of intact femur, Charnley Elite and Summit femoral prostheses were developed. The stress distributions on the femur and the implants were measured. Applied with hip joint loading and related muscles strength, the stress changes of an intact femur and those implanted with either Charnley Elite or Summit protheses, especially changes in proximal femur, were respectively quantitatively analysed. Results Com-pared with intact femur, there was no change of the full-length femur stress pattern in implantation of both implants, the areas of peak values were all presented at middle and lower regions of the femur, and femoral stress value levels were decreased with both implants. Both prostheses induced significant decrease of stress in the periprosthetic bone tissue, the most serious loss of stresses all appeared at femoral calcar, the stress-shielding rates of Elite and Summit prostheses were 90.8% and 95.3% respectively. The distributions of stress shielding of both prostheses were consistent each other, the Summit proximal porous cementless pros-thesis had more serious stress decrease than the Charnley Elite cemented prosthesis. Conclusion Implan-tation of both implants may cause significant stress shielding in the proximal femur. This may be related with periprosthetic bone loss and aseptic loosening of stems, and can be used to explain the mechanism of post-operative femoral fracture and thigh pain. Both implants designs need further improvement to reduce stress changes in proximal femur.

Objective:To clone chickens MxA gene, construct its recombinant expression plasmid and induce the expression of fusion protein using a prokaryotic expression system.Methods:The MxA gene fragment was amplified by RT-PCR from CEF cells and subcloned into the pMD18-T vector, filtrated the positive clone and reclaimed the MxA.Subcloned the MxA into the prokaryotic expression plasmid pGEX-6p-1. After recombinant plasmid was induced by IPTG, the expressed proteins were analyzed by SDS-PAGE, the NDV intervence experiment and VSV-CEF restrain experiment.Results:The sequence of MxA gene amplified by RT-PCR was the same as the sequence in gene map of Genebank; SDS-PAGE, the NDV intervence experiment and VSV-CEF restrain experiment showed that a protein was expressed, the molecular weight of this protein was 45 000, which was the same as the fusion protein GST-MxA.Conclusion:The MxA is cloned and its recombinant expression plasmid is constructed successfully.The fusion protein GST-MxA is successfully expressed in the prokaryotic expression system E.coli DH5? induced by IPTG. This research lay a foundation for further studying on ints antiviral effects and exploring new way of antiviral medication.

ObjectiveTo investigate the efficacy of percutaneous pedicle screw fixation combined with transpedicular interbody bone grafting for the treatment of thoracolumbar fractures.MethodsA total of 20 patients with thoracolumbar fractures (type A,load sharing ≥7,without neurological deficit) underwent percutaneous pedicle screw fixation of Sextant systems combined with transpedicular interbody bone grafting were retrospectively studied.The perioperative parameters,radiographic and clinical outcomes were compared with another 20 patients underwent traditional short-segment pedicle screw fixation combined with transpedicular interbody bone grafting.All patients were followed up for at least 2 years after surgery.ResultsThere were no significant differences between the two groups in sex,age,injury to operation interval,and load sharing scores.However,there were significant differences between the two groups in operating time and blood loss(P＜0.05).The vertebral body height and kyphosis angle were corrected significantly after surgery (P＜O.05),however,the recovery of the vertebral body height and kypbosis angle were reduced significantly one year after surgery in both groups (P＜0.05).At the final follow-up,there were no significant progressive losses of the recovery of the vertebral body height and kyphosis angle,as compared with that of one year after surgery in two groups.There were no significant differences in radiographic parameters and the clinical outcomes between the two groups,even though less radiographic correction and better clinical outcomes were found in percutaneous techniques.ConclusionShort-segment pedicle screw fixation with transpedicular grafting remains a reliable surgical method for the treatment of severe thoracolumbar fractures without neurological deficit.Percutaneous pedicle screw fixation proved to be an effective method with the advantages of minimal invasiveness and less blood loss.

Objective To investigate the correlation between sagittal spinal and pelvic parameters in different types of degenerative lumbar scoliosis (DLS).Methods Standing anteroposterior and lateral radiographs of the whole spine including hip joints were carried out in 70 volunteers without spinal deformity and 110 patients with DLS.The following parameters were measured:thoracic kyphosis (TK),thoracolumbar kyphosis (TL),lumbar lordosis (LL),sagittal vertical axis (SVA),pelvic incidence (PI),pelvic tilt (PT) and sacral slope (SS).According to the sagittal spinal alignment,the patients with DLS were classified into 3 types:type Ⅰ (45 cases),type Ⅱ (48 cases) and type Ⅲ (17 cases).The sagittal spinal and pelvic parameters were compared between control group and different types of DLS group,and the relationship between the sagittal spinal parameters and pelvic parameters in different groups were also investigated.Results PI in type Ⅲ patients was lower than those in other groups; PT in type Ⅱ and Ⅲ patients was higher than those in controls and type Ⅰ patients,and there was a significant difference between type Ⅱ and Ⅲ patients; SS in type Ⅱ and Ⅲ patients was lower than those in controls and type Ⅰ patients,and there was no significant difference between type Ⅱ and Ⅲ patients.Sagittal spinal imbalance was found in 17.8％ of type Ⅱ patients and 29.4％ of type Ⅲ patients.There were significant correlations in sagittal spinal parameters,pelvic parameters and spinopelvic parameters in controls and type Ⅰ patients.However,in type Ⅱ and Ⅲ patients,the correlations in sagittal spinal parameters and spinopelvic parameters decreased,even disappeared,though significant correlations were still found in pelvic parameters.In any group,SVA showed a significant correlation with LL and PT,especially with PT.Conclusion The sagittal spinal alignment has a ladder-like change in patients with DLS,and the correlations in pelvic parameters and spinopelvic parameters also change in type Ⅱ and Ⅲ patients,for whom the sagittal spinal imbalance is more likely to occur.

Objective To evaluate the clinical efficacy of anterior C2-3 discectomy and fusion in treatment of type Ⅱ traumatic spondylolisthesis of the axis. Methods A total of 27 patients with type Ⅱ traumatic spondylolisthesis of the axis were treated with anterior C2-3 discectomy, fusion and plate fixa-tion. There were 19 males and 8 females, at average age of 38 years (22-67 years). The spinal cord function was at Fraukel D in four patients. Results Operation lasted for 75-95 minutes (mean 86 mi-nutes), with blood loss of 100-160 ml (mean 135 ml). Hospital stay was 9-12 days ( mean 10.8 days). Follow-up for 9-24 months (mean 14 months) showed that all patients achieved bony fusion within three months postoperatively, with no anterior displacement or kyphosis. The range of cervical movement was normal, with no chronic neck pain ocurred. Conclusions Anterior approach can minimize surgical trauma, shorten recovery time and hospital stay. Anterior C2-3 discectomy and fusion is a feasible and safe surgical technique and can get satisfactory therapeutic effect in treating type Ⅱ traumatic spondylolisthesis of the axis.

Objective To determine the outcome of unstable atlas fractures combined with rupture of transverse ligament treated by posterior atlantoaxial transpedicular screw fixation.Methods A retrospective case series study was made on 17 patients with unstable atlas fractures combined with rupture of transverse ligament treated by posterior atlantoaxial transpedicular screw fixation and fusion from January 2008 to December 2015.There were 13 males and 4 females,with age range of 34-69 years (mean,47.8 years).All atlas fractures were Jefferson fractures (Levine-Edwards type Ⅲ).Classification of transverse ligament rupture was type Ⅰ in 12 patients and type Ⅱ in 5 patients.No patients had neurologic deficit [American spinal injury association (ASIA) classification grade E].Operation time,blood loss,implant failure,bone fusion and visual analogue scale (VAS) were recorded after operation.Results Operation time was 85-120 min (mean,102 min).Blood loss was 90-150 ml (mean,115 ml).All patients were followed up for 10-20 months (mean,17.8 months).At the final follow-up,all patients achieved bone union,with no implant loosening or breakage happened.VAS was improved from preoperative (5.5 ± 1.8) points to (2.4 ± 1.5) points at tbe final follow-up (P ＜ 0.05).ASIA Grade E remained in all patients.Conclusion Posterior atlantoaxial transpedicular screw fixation of unstable atlas fractures combined with rupture of transverse ligament is a safe and effective surgical procedure that is able to restore the atlanto-axial vertebral stability and relieve pain.

Objective To investigate the consistency of M RI detecting posterior ligamentous complex (PLC) injury associated with thoracolumbar factures.Methods MRI data of 170 cases of thoracolumbar fractures were reviewed retrospectively.Each case underwent MRI around one week postinjury.MRI data were analyzed and compared by three physicians respectively to discuss the consistency in MRI detection of PLC injury and the severity of PLC injury.Results Kappa coefficient was 0.846 between observer 1 and 2,0.768 between observer 1 and 3,and 0.793 between observer 2 and 3.Interobserver reliability was high and overall Kappa coefficient was 0.803.Severity of PLC injury was interrelated with spinal cord nerve injury (P ＜ 0.05).Conclusions Accurate detection of PLC injury in thoracolumbar fractures is beneficial to clear the mechanical stability of the spine.MRI detection of PLC injury is of high consistency and hence deserves wide use.

Objective To investigate the distribution characteristics of pathogenic bacteria among different seasons and ages in children lower respiratory tract infection.Methods To retrospectively analyze the results of bacterial culture in pediatric outpatients and inpatients with lower respiratory tract infections in our hospital from September 2014 to August 2015.The pathogenic bacterial detection situation of lower respiratory tract infection among different age groups and different were statistically analyzed.Results A total of 2 809 pathogenic bacterial strains were isolated from 4 629 lower respiratory tract specimens,and detection rate was 60.7%.The pathogenic bacteria distribution was different among different age groups.Haemophilus influenzae (33.3%) ranked the first place in the lower respiratory infection among children aged from 19 d to 7 year old.The detection rates of Haemophilus parainfluenzae,Moraxella catarrhalis and staphylococcus aureus had obvious seasonality,while Streptococcus pneumoniae had no obvious seasonality.Conclusion Pathogenic bacteria causing lower respiratory tract infections in children are different from those in adults,which are affected by age and seasonal change.