BACKGROUND: Posterior lumbar non-fusion devices have been developed to control vertebral column movement, change load pattern of instability segment, restrict abnormal action, as well as avoid adjacent segment degeneration.OBJECTIVE: To investigate the efficiency of Wallis dynamic stabilization system in the treatment of lumbar vertebrae instability.METHODS: Ten cases suffering from lumbar instability were selected, including 3 males and 7 females, aged 43-65 years. One patient sustained L_(1/2) and L_(4/5) segmental instability, one was L_(2/3) and another was L_(3/4), and the others were L_(4/5). Two patients complicated with lumbar disc herniation and 7 patients combined with lumbar spinal stenosis at the same affected segment, and 3 patients associated with lumbar spinal stenosis at adjacent segment. All unstable segments were treated with decompression, posterior implantation of Wallis dynamic stabilization system. Visual analogue scale (VAS) and Japanese Orthopedic Association (JOA) scores for low back pain and Oswestry disability index (ODI) were used to evaluate clinical outcomes. In addition, therange of motion (ROM) at the instrumented segment and adjacent segments and posterior disc height (PDH) in standing and extension position at L_(4/5) segment were also measured.RESULTS AND CONCLUSION: All the patients were followed-up for 2-13 months, mean 9.2 months. The mean operation duration was 128 minutes (90-185 minutes), with bleeding volume of 264 Ml (50-600 Ml). Sings and symptoms of all patients were improved significantly after operation, except one patient with recurrence of L_(4/5) lumbar spinal stenosis at 3 month after surgery, whose symptoms relieved by revision with fenestration and decompression. The postoperative VAS was dramatically decreased than that of preoperation (P=0.003); the JOA score was obviously increased (P=0.002), and the ODI score was decreased (p=0.008). The postoperative range of motion decreased significantly (P<0.05). However, there was no obviously difference between preoperative and postoperative L_(3/4), L_5/S_1 and posterior disc height (P>0.05). Good clinical results can be achieved by surgical intervention with Wallis dynamic stabilization system in treating lumbar vertebrae instability.

BACKGROUND:Hydroxyapatite (HA) artificial bone,as bone grafting substitute,would not cause inflammatory reaction or immunological rejection and possesses good biocompatibility after transplantation into human body.It is a novel implant material with bone conduction ability.OBJECTIVE:To investigate the efficacy of HA artificial bone in bilateral open-door posterior cervical expansive laminoplasty and to make a comparison with autogenous bone.DESIGN,TIME AND SETFING:A retrospective case analysis was performed at the Department of Spine Surgery,Hungpuyuan Branch,the First Affiliated Hospital of Sun Yat-sen University from March 2001 to December 2008.PARTICIPANTS:Seventy patients with cervical spondylosis complicated by compression in 3 or more segments or by cervical stenosis and additional fifteen patients with cervical stenosis complicated by cervical trauma were included in this study.METHODS:A bilateral open-door posterior cervical expansive laminoplasty was performed,in which,23 patients received autogenous bone transplantation (autogenous bone group) and 62 patients underwent HA artificial bone transplantation (HA group).MAIN OUTCOME MEASURES:① Japanese Orthopaedic Association (JOA) score pdor to and after surgery,surgery time,and intraoperative bleeding.② HA artificial bone-host biocompatibility.RESULTS:All eighty-five patients were followed up for more than 3 months.There was no significant difference in JOA scores no matter prior to or after surgery between the autogenous bone and HA groups (P＞0.05).The surgery time averaged 85.2 minutes (range 65-110 minutes) in the HA group and averaged 116.4 minutes (range 75-150 minutes) in the autogenous bone group.The intraoperative bleeding averaged 210 mL (range 130-400 mL) in the HA group and averaged 260 mL (range 170-500 mL) in the autogenous bone group.There were no material-host response and other severe complications found in each group,except HA artificial bone fragmentation in 3 patients from the HA group.CONCLUSION:HA artificial bone yields good efficacy and causes fewer complications in bilateral open-door posterior cervical expansive laminoplasty;in addition,it requires less time for surgery and causes less bleeding.

BACKGROUND:Antedor canulated screw has been considered an ideal method to treat odontoid fracture.OBJECTIVE:To compare the biomechanical properties of different anterior screws.DESIGN,TIME AND SETTING:A randomized contrast study was performed at the Biomechanics Laboratory of Southern Medical University from March to September 2006.MATERIALS:Double-thread canulated screws and single-thread canulated screws were made of titanium alloy and provided by Shuangyang Medical Apparatus Co.,Ltd.,Suzhou.METHODS:A total of head-neck complexes (C0-C3) which were collected from 20 corpses were maintained in formaldehyde for less than 3 months;thereafter,the muscles and ligaments were removed to obtain the axis specimens so as to make type Ⅱ odontoid fracture models.The fracture samples were individually treated with double-thread and single-thread canulated screws,with 10 samples for each group.MAIN OUTCOME MEASURES:The shear stiffness and the maximum resistance of the two kinds of screw were tested in this study.RESULTS:The shear stiffness of the double-thread screw group was significantly higher than the single-thread screw group (P＜0.01 );however,there was no significant different in the maximum resistance between the two groups (P＞0.05).CONCLUSION:Double-thread canulated screws have a strong biomechanical stability for treating odontoid fracture;therefore,the first choice of the internal fixation should be double-thread canuiated screws for patients with osteoporosis or those who are susceptible to expanded screw pathway during surgical procedures.

Objective To explore the executive function in patients with mild traumatic brain injury (mTBI). Methods The evaluation of executive function was conducted in 63 mTBI patients in 1 week, 1, 3 and 6 month after injury and 60 health controls. The executive function was evaluated using Trail Making Test (TMTA), Hopkins Verbal Learning Test-revised (HVLT-R), Brief Visuospatial Memory Test-revised (BVMT-R), Stroop Color Word Tes and Con-tinuous Performance Test (CPT). Results There were significant differences between mTBI patients and controls in TM-TA, HVLT-R, BVMT-R, Stroop Color Word Test and CPT a week following TBI (P<0.05). There were a significant in-crease in scores of TMTA and a significant decrease in HVLT-R, BVMT-R, stroop and CPT-IP at 1, 3 and 6 month compared with 1 week following TBI (P<0.05). There were a significant decrease in TMTA and a significant increase in BVMT-R and stroop 1 month compared with 1 week following TBI (P<0.05). There were a significant increase in stroop, BVMT-R and CPT-IP at 3 month compared with 1 month following TBI (P<0.05). There was a significant increase in stroop and CPT-IP at 6 month compared with 3 month following TBI (P<0.05). Conclusions Patients with mTBI have executive function impairment. The recovery times of different executive function are different in patients with mTBI.

The mammalian target of rapamycin (mTOR) signaling pathway plays an important role in tumorigenesis, development of tumor and tumor therapy. Previous studies have reported on the abnormalities of mTOR signaling pathway leading to the development of a variety of malignant tumors and the antitumor efficacy of various mTOR inhibitors. However, multiple studies in recent years on the mechanisms of drug resistance in tumor therapy with chemotherapy or programmed death receptor 1 inhibitors have focused on the possibility that inhibition of mTOR signaling may be associated with tumor resistance to therapy. This article summarizes the physiological functions of mTOR signaling pathway and its regulatory mechanisms in tumorigenesis, and provides a review for its mechanism of action in tumor therapy sensitivity.

Lumbar spondylolysis refers to the bone injury between the upper and lower articular processes and the transition zone of the transverse process of the unilateral or bilateral pedicle of the lumbar spine, being a common cause of low back pain in patients that seriously affects their quality of life. The mechanism of the occurrence and development of lumbar spondylolysis is complex, and long-term stress wear and sudden damage with an external force are the main causes. At the same time, risk factors related to spinal anatomy are important causes of lumbar spondylolysis. A full understanding of the pathogenesis of lumbar spondylolysis, early identification of high-risk groups, and active preventive measures can reduce its incidence. For this purpose, the authors reviewed the research progress in risk factors related to the spinal anatomy of lumbar spondylolysis from three aspects including genetical susceptibility, local anatomy and overall spine-pelvic sequence, so as to provide references for the prevention and treatment of spondylolysis.

Objective:To explore the blood pressure levels and the influencing factors of hypertension among Hainan centenarians, and provide basic data for the further blood pressure related studies of the centenarian population.Methods:The baseline data were from China Hainan Centenarian Cohort Study (CHCCS). This cross-sectional data, based on the community population, was a complete sample study of centenarians, including questionnaire survey, physical examination and physiological index detection. A total of 1 002 centenarians were recruited to describe the blood pressure level. According to the guidelines for the prevention and treatment of hypertension in Chinese adults in 2018, the prevalence of hypertension was analyzed.Results:The median levels of systolic blood pressure, diastolic pressure and pulse pressure were 152.0, 76.0 and 76.5 mmHg, respectively. Blood pressure level was higher in females than in males. The prevalence of hypertension was 71.9%, mainly in isolated systolic hypertension with the prevalence of 60.1%. The results of multivariate analysis showed that the risk of hypertension in women was higher than that in men ( OR=1.624, 95% CI: 1.155-2.283), and the risk of hypertension in the northern ( OR=0.625, 95% CI: 0.434-0.901) and central areas ( OR=0.586, 95% CI: 0.346-0.993) was lower than that of the Eastern. Conclusion:The prevalence of hypertension, mainly in isolated systolic hypertension, showing gender and regional distribution differences.