Role of crenel lateral lumbar interbody fusion in the precise selection of fusion level in posterior correction for adult degenerative scoliosis / 中华外科杂志

Objective: To investigate the role of minimally invasive crenel lateral lumbar interbody fusion (CLIF) in the decision of fusion level in posterior correction for severe adult degenerative scoliosis. Methods: This is a prospective study.Patients with level Ⅴ and Ⅵ of Lenke-Silva classification who were treated at Department of Orthopedics,the Second Affiliated Hospital, School of Medicine, Zhejiang University from June 2016 to March 2019 were included.First,the enrolled patients completed the preoperative clinical and imaging examination,the Lenke-Silva classification was evaluated,the surgical segments in first-stage CLIF was determined and the fusion segments required for single-stage posterior correction was predicted.After the first-stage CLIF,patients received reassessment of Lenke-Silva classification and global coronal and sagittal balance.Patients were divided into two groups:the effective group (level of Lenke-Silva classification decreased) and the ineffective group (level of Lenke-Silva classification unchanged).Second-stage posterior surgery was performed based on the results of reassessments.The fusion segment,Cobb angle,parameters of global coronal and sagittal plane,visual analogue pain score (VAS) and Oswestry disability index (ODI) were compared between the two groups preoperatively,after first-stage CLIF,second-stage posterior fixation and at the final follow-up.The potential factors associated with the decrease of the level of Lenke-Silva classification were recorded and compared between the two groups.Independent sample t test,repeated measure analysis of variance,rank sum test,χ2 test or Fisher exact method were used to compare the difference among groups. Results: Fifty-four patients were enrolled,including 8 males and 46 females,aged (68.8±5.8) years (range:56 to 77 years).Preoperatively,26 patients were classified as level Ⅴ by Lenke-Silva classification,28 cases were grade Ⅵ.CLIF was performed in 194 segments,with 114 segments(58.8%) receiving anterior column realignment (ACR) and 15 segments(7.7%) using hyperlordotic cages.After first-stage CLIF,22 patients with level Ⅴ and 10 patients with Ⅵ of Lenke-Silva classification decreased and were classified into effective group.The level of the remaining 4 patients with level Ⅴ and 18 patients with grade Ⅵ unchanged and were classified into ineffective group.Preoperatively,the apical vertebrae was below L1 in all 32 patients of effective group and 18 (81.8%,18/22) patients of ineffective group.The difference was statistically significant (P=0.023).There were 7 (31.8%,7/22) patients had continuous osteophyte in front of the intervertebral space in ineffective group,while none patient had continuous osteophyte in front of the intervertebral space in effective group,and the difference was statistically significant (P=0.001).In first-stage CLIF,more intraoperative ACR(71.2% vs.39.5%,χ²=20.660,P<0.01)and hyperlordotic cage (12.7% vs.0,P=0.001) were used in the effective group,while there was less severe cage subsidence after the operation (5.9% vs.15.8%,χ²=4.793,P=0.029) in effective group.After first-stage CLIF,there was no difference in the Cobb angle between the two groups.While,lumbar lordosis (LL) in effective group (34.0±8.3)° was greater than that of the ineffective group (25.5±9.7)° (t=3.478,P=0.001),and the difference between the pelvic incidence (PI) and LL in effective group (15.7±4.6)°was significantly smaller than ineffective group(20.0±10.8)° (t=-2.129,P=0.038).The posterior fusion levels was less,the rate of fusion to thoracic spine region and the actual fusion segment was less than that of single-stage posterior correction in effective group (all P<0.01).All patients were follow-up for 24 to 45 months.There was no significant difference in radiological and clinical results between the two groups after first-,second-stage surgery and at the final follow-up (all P>0.05). Conclusions: First-stage CLIF decreased the Lenke-Silva classification of some patients with severe degenerative scoliosis.Combined with the reassessment of Lenke-Silva classification and global coronal and sagittal plane,it helps to accurately determine the fusion segment.Decrease of Lenke-Silva classification is associated with the preoperative level of apical vertebrae,continuous osteophytes in front of the intervertebral space,intraoperative use of ACR and hyperlordotic cage and the degree of cage subsidence postoperatively.

Comparative study of minimally invasive percutaneous pedicle screw fixation and open surgery in the treatment of thoracolumbar fractures / 中国骨伤

<p><b>OBJECTIVE</b>To compare the clinical outcomes of minimally invasive percutaneous pedicle screw fixation and open surgery in the treatment of thoracolumbar fracture.</p><p><b>METHODS</b>A retrospective study of patients who had undergone surgery for thoracolumbar fracture from June 2014 to December 2014 was performed. Sixty-one cases were included and 29 cases were treated by minimally invasive percutaneous pedicle screw fixation (minimally invasive group) and 32 cases were treated by the traditional open pedicle screw fixation(open group). The differences in the total length of the incision, intraoperative fluoroscopy times, operative time, blood loss, the preoperative and postoperative visual analogue scale(VAS), postoperative bedridden time and hospital stay were compared. And the preoperative and postoperative anterior vertebral body height and Cobb angle of the kyphosis were also compared.</p><p><b>RESULTS</b>Compared with the open group, the total length of incision was smaller and intraoperative blood loss was less, bedridden time and hospital stay were shorter, and pain of the wound was less in the minimally invasive group. Postoperatively, the anterior vertebral body height was retorted and the Cobb angle of the kyphosis was corrected obviously in both groups. But no significant difference in the imaging results was found between two groups(>0.05).</p><p><b>CONCLUSIONS</b>Minimally invasive percutaneous pedicle screw fixation has the similar fixation efficacy with open surgery in treating thoracolumbar fracture. However, it can avoid extensive muscle stripping, and obviously reduce the surgical incision, operative time, postoperative pain, bedridden time and hospital stay. According to the clinical efficacy, it is worthy of clinical application.</p>

Multivariate analysis for prognostic factors on non-operative treatment of cervical spinal cord injury without fracture or dislocation / 中国骨伤

<p><b>OBJECTIVE</b>To analyze the factors in the non-operative treatment of cervical spinal cord injury without fracture or dislocation.</p><p><b>METHODS</b>The clinical data of 122 patients with cervical spinal cord injury without fracture or dislocation from January 2009 to December 2012 treated by non-operative treatment were retrospectively reviewed. There were 84 males and 38 females, aged from 18 to 83 years with an average of (52.37 +/- 13.27) years. The clinical features, such as age, gender, cause of injury, time from injury to treatment, ASIA grade of spine cord injury, MRI type of spine cord injury, range of spine cord injury, effective cervical spinal canal ratio, Pfirrmann grade of intervertebral disc herniation, segment of intervertebral disc herniation, intervertebral disc ligament complex injury, treatment of high-dose methyiprednisolone, were observed. Single factor and multiple factor Logistic regression analysis were used in the clinical data in order to analyze the influencing factors of above items to prognosis.</p><p><b>RESULTS</b>For univariate analysis, the factors such as MRI type of spine cord injury, extent of spine cord injury, effective cervical spinal canal ratio, Pfirrmann grade of intervertebral disc herniation, segment of intervertebral disc herniation, ASIA grade of spine cord injury, associated with prognosis (P < 0.05). Multiple linear regression analysis showed that the main prognostic factors including MRI type of spine cord injury, range of spine cord injury, effective cervical spinal canal ratio, Pfirrmann grade of intervertebral disc herniation, ASIA grade of spine cord injury according to its effective intension (P < 0.05).</p><p><b>CONCLUSION</b>The main prognostic factors on non-operative treatment of cervical spinal cord injury without fracture or dislocation were MRI type and extent of spine cord injury, meanwhile, correlate with effective cervical spinal canal ratio, Pfirrmann grade of intervertebral disc herniation, ASIA grade of spine cord injury. It is deliberative to choose no-operative treatment, for it only refers to the patients with the mild localized edema type or no signal change of spinal cord in MRII. Operative treatment shoud be recommended for other patients.</p>

Anterior slip phenomenon of the vertebrae after corpectomy surgery and its clinical significance / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the anterior slip phenomenon of the vertebrae after corpectomy surgery and its clinical significance.</p><p><b>METHODS</b>The clinical data of 164 patients with cervical spondylotic myelopathy treated from January 2010 to April 2013 were retrospectively analyzed. There were 88 males and 76 females, aged from 38 to 74 years old with the mean of 56.2 years. Among them, 31 cases for C₄ corpectomy, 87 cases for C₅ corpectomy, 46 cases for C₆ corpectomy. Preoperative and postoperative distance of posterior wall of vertebral canal to the line of adjacent upper vertebral bodies anterosuperior border and lower vertebral bodies anteroinferior border was measured by CT in cervical sagittal middle layer scanning as the center, anterior slip degree of the vertebrae after operation was evaluated. The fast clustering method was used, the vertebral shift distance as variable, according to the size of the forward distance, 90 cases classified as group 1(forward greatly group), and the 74 cases classified as group 2(forwad short group). The relationships on the anterior slip of the vertebrae and cervical curvature, surgical segment were analyzed. Japanese Orthopaedic Association (JOA) scores and its improvement rate were observed before and after operation, and the relationships on the anterior slip of the vertebrae and sagittal plane diagonal diameter of spinal canal, clinical effect were analyzed.</p><p><b>RESULTS</b>All the patients were followed up from 12 to 48 months with an average of 29.5 months. All operative vertebrae occurred anterior slip with different degree after corpectomy surgery, the maximum was 3.52 mm and minimum was 1.12 mm, with an average of (2.14±1.02) mm. According to the clustering method, the anterior slip distance with (3.07±0.21) mm classified as forward greatly group(90 cases, 54.9%) and the anterior slip distance with (1.55±0.32) mm classified as forwad short group(74 cases, 45.1%). There was no significant difference between anterior slip distance and operation segments(=0.01,=0.996). Cervical curvature index and anterior slip distance of operated vertebra had a positive correlation (=0.724). The incidence of reduction of the diagonal diameter of cervical spinal canal in forward greatly group was higher than that of forwad short group(=4.45,=0.035). The patients with unsatisfactory efficacy appeared obvious anterior slip of the vertebrae after corpectomy than the patients with satisfactory efficacy(<0.05).</p><p><b>CONCLUSIONS</b>Corpectomy of the cervical spine can result in vertebral forward displacement trend, and obvious displacement may cause the secondary compression of the spinal cord.</p>

Clinical effect of posterior atlanto axial vertebra internal fixation for treatment of instability of occipitocervical / 中国骨伤

<p><b>OBJECTIVE</b>To explore radiographic results and clinical effects of posterior atlanto axial vertebra internal fixation in treating instability of occipitocervical.</p><p><b>METHODS</b>The clinical data of 155 patients with instability of occipitocervical treated by posterior atlanto axial vertebra internal fixation were respectively analyzed from September 2005 to January 2011. There were 68 males and 87 females, ranging in age from 6 to 75 years old with an average of 45.6 years old. Of them, 53 cases were fresh odontoid fractures(Aderson type II C), 30 cases were os odontoideum, 20 cases were old odontoid fractures, 18 cases were unstable atlas fractures, 12 cases were atlanto axial rotatory dislocation, 11 cases were atlanto axial dislocation after rheumatoid arthritis, and 11 cases were basilar invagination. Radiographic results were evaluated in terms of atlas pedicle screw fixation, bone healing and bone graft fusion. Clinical effect evaluation included relief of pain in the occipital-cervical region by VAS score and JOA score.</p><p><b>RESULTS</b>Totally 300 screws were set through atlas pedicle screw fixation in 150 patients. Five patients receivde hook fixation. Postoperative CT showed ideal nailing were 275 (91.7%),acceptable nailing were 14 (4.7%) and unacceptable nailing were 11 (3.6%). All patients were followed up, and the duration ranged from 16 to 40 months with an average of 25.4 months. The fresh fractures healed and 140 cases got bone graft fusion. Preoperative VAS and JOA score were respectively improved from (7.2 +/- 1.1), (7.3 +/- 2.4) to (3.2 +/- 1.1), (13.3 +/- 2.4) at the latest follow-up.</p><p><b>CONCLUSION</b>Posterior atlanto axial vertebra internal fixation in treating instability of occipitocervical can effectively recover physiological curvature of cervical, provide mechanical stability, and obtain good clinical effect. For the young patients who require further activity, posterior fixation and non-fusion technology is a good choose, which can avoid bone graft.</p>

Application of internal fixation of steel-wire limited loop in early Achilles tendon rupture

OBJECTIVE@#To explore the clinical effect and safety of internal fixation of steel-wire limited loop in early Achilles tendon rupture.@*METHODS@#Seventy-six patients respectively with early transected and avulsed types of Achilles tendon rupture were selected and treated with internal fixation of steel-wire limited loop. The patients began to take exercise for their lower limbs through continous passive motion as early as possible after surgical repair, and the loops were removed after 3-5 months. Six months later, the condition of complications including Achilles tendon re-rupture, wound fistula, wound infection and skin necrosis, cutaneous sensation in sural nerve dominance region, time back to preinjury work or learning as well as time to physical activities were observed. One year later, the therapeutic effect was evaluated, and the maximum circumferences of bilateral legs and ruptured plane circumferences of Achilles tendon were measured.@*RESULTS@#The wound of all patients healed well, no complications like Achilles tendon re-rupture, wound fistula, wound infection and skin necrosis occured, and the cutaneous sensation in sural nerve dominance region was normal. The mean time back to preinjury work or learning as well as to pysical activities of all patients were respectively 10 and 22 weeks. Seventy out of 76 patients (92.1%) achieved an excellent effect, and 6 (7.9%) good effect. The excellent and good rate came up to 100%. The maximum circumference in the affected leg decreased to 2 mm averagely compared with the offside, while the ruptured plane circumferences of Achilles tendon in the affected side increased to 2.2 mm compared with the offside.@*CONCLUSIONS@#For early Achilles tendon rupture, internal fixation of steel-wire limited loop can recover the ankle function better, return to the preinjury state in the shortest time, and has few complications.

Regulatory Role of Hypoxia Inducible Factor in the Biological Behavior of Nucleus Pulposus Cells

Intervertebral disc (IVD) degeneration is implicated as a major cause of low back pain. The alternated phenotypes, reduced cell survival, decreased metabolic activity, loss of matrix production and dystrophic mineralization of nucleus pulposus (NP) cells may be key contributors to progressive IVD degeneration. IVD is the largest avascular structure in the body, characterized by low oxygen tension in vivo. Hypoxia-inducible factor (HIF) is a master transcription factor that is induced upon hypoxia and directs coordinated cellular responses to hypoxic environments. This review summarizes relevant studies concerning the involvement of HIF in the regulation of biological behaviors of NP cells. We describe current data on the expression of HIF in NP cells and further discuss the various roles that HIF plays in the regulation of the phenotype, survival, metabolism, matrix production and dystrophic mineralization of NP cells. Here, we conclude that HIF may be a promising target for the prevention and treatment of IVD degeneration.

Changes in the expression of platelet-derived growth factor in astrocytes in diabetic rats with spinal cord injury / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Prospective mortality studies in the United States revealed that the mortality was elevated in diabetics compared to normal individuals following chronic spinal cord injury (SCI). Our study was conducted to investigate the levels of platelet-derived growth factor (PDGF) of astrocytes in SCI in streptozotocin (STZ)-induced diabetic rats.</p><p><b>METHODS</b>Thirty male Sprague-Dawley (SD) rats were randomly divided into 3 groups: SCI group, diabetic SCI group, and sham operation control group. We employed STZ-induced diabetic SD rats and a weight-drop contusion SCI model. The rats were sacrificed on day 7 after the induction of SCI. Immunohistochemistry and Western blotting analysis were used to detect the PDGF expression level. Basso, Beattie and Bresnahan locomotor rating scale (BBB) was also used to evaluate the neurological recovery level of the rats.</p><p><b>RESULTS</b>PDGF positive astrocyte numbers were significantly higher and PDGF staining was more intensive in astrocytes in the SCI group than in the diabetic SCI group (P < 0.05). The diabetic SCI group showed a slower recovery of motor function with a lower BBB score 7 days after acute spinal injury.</p><p><b>CONCLUSIONS</b>PDGF is an important factor for the recovery of neurological function after acute spinal injury and hyperglycemia in diabetic rats could depress the expression of PDGF in injured spinal cord. This may help to explain the slower recovery and higher mortality in diabetics after SCI.</p>

Spinal cord decompression reduces rat neural cell apoptosis secondary to spinal cord injury / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>OBJECTIVE</b>To determine whether spinal cord decompression plays a role in neural cell apoptosis after spinal cord injury.</p><p><b>STUDY DESIGN</b>We used an animal model of compressive spinal cord injury with incomplete paraparesis to evaluate neural cell apoptosis after decompression. Apoptosis and cellular damage were assessed by staining with terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate nick-end labelling (TUNEL) and immunostaining for caspase-3, Bcl-2 and Bax.</p><p><b>METHODS</b>Experiments were conducted in male Sprague-Dawley rats (n=78) weighing 300-400 g. The spinal cord was compressed posteriorly at T10 level using a custom-made screw for 6 h, 24 h or continuously, followed by decompression by removal of the screw. The rats were sacrificed on Day 1 or 3 or in Week 1 or 4 post-decompression. The spinal cord was removed en bloc and examined at lesion site, rostral site and caudal site (7.5 mm away from the lesion).</p><p><b>RESULTS</b>The numbers of TUNEL-positive cells were significantly lower at the site of decompression on Day 1, and also at the rostral and caudal sites between Day 3 and Week 4 post-decompression, compared with the persistently compressed group. The numbers of cells between Day 1 and Week 4 were immunoreactive to caspase-3 and B-cell lymphoma-2 (Bcl-2)-associated X-protein (Bax), but not to Bcl-2, correlated with those of TUNEL-positive cells.</p><p><b>CONCLUSION</b>Our results suggest that decompression reduces neural cell apoptosis following spinal cord injury.</p>

Surgical treatment of type-C thoracolumbar fractures / 中国骨伤

<p><b>OBJECTIVE</b>To explore the operative approach and method of internal fixation for the treatment of type-C thoracolumbar fractures.</p><p><b>METHODS</b>T wenty-eight patients (male 20, female 8, ranging in age from 20 to 54 years, with an average of 38.5 years) with type-C thoracolumbar fractures were invovled in the study. Distributed segments involved T11 in 2 patients, T12 in 3 patients, L1 in 11 patients, L2 in 8 patient, L3 in 3 patients and L4 in 1 patient. Twenty-six patients were followed up (range from 12 to 20 months). According to the analysis of X-ray and CT image,height of vertebral body, Cobb angle on sagittal and coronal plane and the percentage of occupancy of vertebral canal were measured. The recovery of nerve, happening of back pain and the failure of internal fixation were observed.</p><p><b>RESULTS</b>The preoperative averaging height-loss decreased from 37.4% to 6.8% and the deformation of coronal plane was completely rectified. The preoperative averaging Cobb angle on sagittal plane recovered from 22.3 degrees to 5.6 degrees and the preoperative occupancy of vertebral canal averaging recovered from 33.7% to 5.9%. The difference was statistically significant (P < 0.05). Moreover, after 1 year follow-up, the changes of the above-mentioned index was no statistically significant (P > 0.05). Except for 8 patients with complete nerve damage losing the possibility of recovery, the others with incomplete nerve damage obtained 1 to 3 degree's improvement. The ratio of back pain occurrence was 19.2%. There was no failure of internal fixation.</p><p><b>CONCLUSION</b>The treatment of thoracolumbar type-C fractures with simple posterior long-segment internal fixation or posterior long-segmental fixation added by anterior autograft fusion is a reliable and effective method. The short-term therapeutic effect is satisfactory and the long-term therapeutic effect is to be further observed.</p>

Application of lumbar discography in the diagnosis and treatment of the discogenic lumbodynias / 中国骨伤

<p><b>OBJECTIVE</b>To explore the diagnostic value of lumbar disc imagery applied for patients with discogenic lumbodynias and the outcome of lumbar fusion and the significance of the imagery technique in choosing the joints and sections for fusion.</p><p><b>METHODS</b>The lumbar imagery technique was applied for 35 patients who suffered from discogenic lumbodynias, involving 74 discs. All the cases got MRI and CT scanning. The results of the imagery and MRI were observed and induced pains were recorded. According to the imagery results, 20 out of the 35 patients received lumbar fusion and were followed up.</p><p><b>RESULTS</b>Among 35 patients, the induced pains occurred at 22 discs in 20 patients (57.1%). All the 22 segments in 20 patients with positive reaction were given lumbar fusion. The follow-up time was 10 months to 2 years with an average of 15 months. Based on the renewed MacNab standard, the results were excellent in 13 cases,good in 4 cases, fair in 2 cases, bad in 1 case. Fifteen patients with negative reaction were given conservative treatment and pains disappeared completely in 5 patients, disappeared nearly in 7 patients, no changes or became worse in 3 patients. Six patients including 9 lumbar discs neighboring the fusion segments who were found no changes in MRI scan and no induced pains in lumbar discography, were not given fusion treatment. Meantime, 1 patient was given fusion treatment because his neighboring symptom-free discs getting more deteriorative resulted in the happen of serious symptoms.</p><p><b>CONCLUSION</b>Lumbar imagery technique has its unique value in the diagnosis and selective treatment of lumbar-disc-related pains. Lumbar fusion of the intervertebral space causing pains can eliminate the suffering of patients. It is appropriate to select those deteriorating discs with symptoms in deciding the fusion segments.</p>

Research on safe implantation of upper-middle thoracic pedicle screws under the X-ray perspective / 中国骨伤

<p><b>OBJECTIVE</b>To explore the method of implanting upper-middle thoracic pedicle screws under monitoring by X-ray and evaluate accuracy and safety.</p><p><b>METHODS</b>(1) Six normal adult thoracic spine samples (T1-T8) were selected, from which single spine units were separated. A surgical probe went in along the pedicle axis. By C-shaped arm X-ray, the four probe positions were recorded: at the entering point, the front end of the probe in the middle of the pedicle, at the pack of the spine, and under the cortex of the front of the spine. The position of the front end of the probe at the entering point, and the front end of the probe at different depth at central-side perspective position were analyzed. The related positions and their corresponding changing rules were also analyzed. (2) Based on the changing rules mentioned above, different steps were adopted under the guidance of the C-shaped arm X-ray, to safely implant upper-middle thoracic pedicle screws. First, six T1-T8 spine samples were used, and under the guidance of the C-shaped arm device, 96 pedicle screws were implanted. After the operation,the sping samples were scanned through CT, and the positions of the screws were determined.</p><p><b>RESULTS</b>According to the result of the CT scanning, the result were excellent (the screw was safely inside the pedicle) in 90 screws; Medium (the screw penetrated a little of the inside or outside bone cortex, within 2 mm) in 6; No one was had (the screw penetrated a lot, more than 2 mm).</p><p><b>CONCLUSION</b>The implantation of upper-middle thoracic pedicle screw under the guidance of the C-shaped arm X-ray perspective is a simple and feasible method, and improve the accuracy and safety.</p>

Diagnosis and treatment of odontoid fracture combined with lower cervical spinal injury / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the mechanism, clinical features and treatment of odontoid fracture combined with lower cervical spinal injury.</p><p><b>METHODS</b>From January 1999 to December 2004, 57 cases of type II or shallow type III odontoid fractures were studied retrospectively. Six cases were found combined with lower cervical injury, the mean age was 54 years, and 4 of the 6 cases were complicated with cervical spondylarthrosis or ankylosing spondylitis. For the lower cervical injury, fracture-dislocation was found in 2 cases, the disruption of disc and ligament was found in 4 cases among which 2 cases were suffered from incomplete spinal cord injury; Both were caused by lower cervical spinal injury. All of the 6 cases were performed with surgery in odontoid fracture and lower cervical spinal injury simultaneously; Lower cervical spinal injuries were stabilized firstly in 2 cases, which responsible for neurological involvement; For the other 4 cases without neurological involvement, stabilization was performed in odontoid fracture firstly in 2 cases, due to inability to achieve reduction of odontoid fracture preoperatively, however, for the another 2 cases with anatomic reduction of the odontoid fracture preoperatively, lower cervical injuries were stabilized firstly.</p><p><b>RESULTS</b>After an average follow-up of 10 months, all cases were obtained solid fusion both in odontoid fracture and lower cervical spinal injury, and without the complications associated with operation and prolonged bed rest. Two cases with neurological defect improved 1 scale in Frankel score.</p><p><b>CONCLUSIONS</b>The incidence of odontoid fracture combined with lower cervical spinal injury is about 10.5% of the odontoid fracture, and it is vulnerable in the elderly patient with cervical spondylarthrosis. MRI should be used routinely for accurate diagnosis. Surgical stabilization is the choice of treatment due to facilitating early rehabilitation and reducing the complications. The surgical schedule is planned according to the fact of neurological involvement and the extent of stability between the odontoid fracture and lower cervical spinal injury.</p>

The influences of lactose as an inducer on expression of plant des-pGlu1-brazzein in Escherichia coli / 生物工程学报

Expression strain of des-pGlu1-brazzein was constructed and the conditions using lactose as inducer was also optimized. The Influences of three factors which were lactose concentration, induction time and inducing temperature on the growth of strain and on the yield of des-pGlul-Brazzein was analyzed in detail. The result indicated that high lactose concentration inhibit the growth of strains (P < 0.01) but made no difference on expression of target protein between 0.5%-5% (P > 0.05), Biomass would be improved as time passed (P < 0.01), but the yield of target protein didn't increase obviously at 30 degrees C compared with at 37 degrees C. Further result showed that the greater expressed level of des-pGlul-Brazzein, as high as about 20% of total cell protein, could be achieved after the strain had been induced with 0.5% lactose under 28 degrees C - 30 degrees C for 4 h.

Safe region for screw fixation in atlas lateral mass and its clinical application / 中华创伤杂志

Objective To investigate the safe region for screw fixation in atlas lateral mass by ra- diologic measurements to conduct the operative procedure.Methods The dimensions of the pedicles were determined in 30 patients with normal atlas by CT scan and three dimensional reconstruction images of the upper cervical spine.The space available for the screw(SAS)was defined as the perpendicular distance between two lines tangential to the spinal canal and the transverse foramen,respectively.SAS was evaluated at 0?(SAS1)and 10?(SAS2)insertion angles.The location of screws in 13 cases of opera- tion were observed by CT scan images measurements of the cervical spine.Results SASI at 0?inser- tion angle was(7.81?1.28)mm and SAS2 at 10?insertion angle was(9.69?1.23)mm,with statisti- cal difference(P＜0.01).For SAS1,the distance from the midline of pedicle to the midline of posterior arch and the distance from the center of C2 inferior articular process to the midline of posterior arch showed insignificant statistical difference.However,the entry point at the posterior arch of the midline of SAS2 was located at 2.0 mm lateral to the midline of ASAI.Twenty-six pedicle screws in 13 cases were inserted correctly,without cortex breakage,or nerve and vessel injury.Conclusions There is a safe region for screw fixation in atlas lateral mass.Wider space available for the screw can be acquired when transverse angle is 10?.It is necessary to confirm the safe region by using axial CT of atlas before screw fixation.