ABSTRACT
BACKGROUND:Vertebral compression fractures are the most common vertebral fractures in the elderly patients with osteoporosis, and the correlation between the compression of anterior border of vertebral body and adjacent vertebral refractures is not clear. OBJECTIVE:To establish a model of different compression of T12vertebral body with finite element method, and analyze the relationship between the compression of T12vertebral body and the stress of adjacent vertebral plate. METHODS:Based on thoracolumbar CT data of normal adult volunteers, MIMICS/3-matic was imported. Through image segmentation, repair and three-dimensional mesh of accessto thoracic and lumbar T11-L1data, grid assigned material properties was imported to ABAQUS so as to establish ligament, joint and other small features and obtain realistic three-dimensional finite element model. The six degrees of freedom, including anteflexion, posterior extension, left and right flexion, left and right rotation, were loaded, to verify the validity of the normal model. With the frontier of vertebral body compression to 90%, 80%, 70%…10% of the nine states, MISES stressesof the T11andL1segment intervertebral disc endplate were extracted; the relationship curve of compression state and endplate stress was obtained. RESULTS AND CONCLUSION:(1) The model was highly realistic and could reflect the actual stress state. (2) The stress value of T11vertebral body and L1vertebral body was positively correlated with the compression of T12vertebral body. Increased stress may lead to an increased likelihood of end plate fractures, which increases the risk of fractures in the adjacent vertebralbodies.
ABSTRACT
BACKGROUND:The type of simply youth compressibility fracture of thoracic and lumbar spine with posterior vertebral injury nailing reset scheme can effectively reset with mechanics from the rear, but due to bone characteristics of the youth, the rear force cannot effectively open anterior and middle columns. To improve the effect of rear reset during the operation becomes the focus of clinical attentionand difficult issues. OBJECTIVE:To retrospectively analyze reset reconstruction effects of posterior screw rod fixation for youth thoracolumbar simple flexion compression fracture. METHODS:Patients with youth thoracolumbar simple flexion compression fracture were treated with posterior screw rod fixation from June 2014 to June 2015. Perioperative indicators (operation time, blood loss, average length of stay and complication rate) were recorded. Patients were folowed up. Imaging indexes (anterior height of vertebral compression, Cobb angle of the injured vertebra) and subjective effect index (low back pain visual analog scale and the Oswestry Disability Index) were observed. RESULTS AND CONCLUSION:(1) Imaging index: Anterior height of vertebral compression and Cobb angle of the injured vertebra were significantly improved after treatment (P 0.05). (2) Subjective effect index: low back pain visual analog scaleand the Oswestry Disability Index were significantly improved after treatment (P 0.05). (3) No nerve injury complications appeared in al patients, without leakageof cerebrospinal fluid. (4) Results indicated that extended posterior screw rod fixation for youth thoracolumbar simple flexion compression fracture can obtain effective reduction due to special bone characteristics of the youth, improve reduction efficiency, do not increase patient’s trauma and the effects are affirmative.
ABSTRACT
BACKGROUND:Due to special physiological and anatomical location, stability of the spine is very complicated during thoracolumbar fractures. It is difficult to identify the stability of the spine. It should be based on their individual circumstances, to explore more effective internal fixation repair method. OBJECTIVE:To explore the Cobb’s angle and vertebral height of patients with thoracolumbar fracture and spinal cord compression treated with posterior laminectomy and screw fixation, and compared with anterior laminectomy. METHODS:One hundred patients with thoracolumbar fracture and spinal cord compression, who were treated in the Panyu District Central Hospital from January 2013 to November 2014, were enroled in this study. The patients were equaly and randomly divided into posterior laminectomy fixation group and anterior laminectomy fixation group. Tactile and sports of American Spinal Injury Association scores, Cobb’s angle and vertebral height were assessed before treatment and 1 month after treatment, and fixation effects were compared between the twogroups. RESULTS AND CONCLUSION:(1) No significant difference in each index was detected between the two groups preoperatively (P> 0.05). (2) Tactile and sports of American Spinal Injury Association scores, Cobb’s angle and vertebral height were better in the posterior laminectomy fixation group than in the anterior laminectomy fixation group at 1 month postoperatively (P< 0.05). (3) These findings indicated that compared with the anterior laminectomy fixation, posterior laminectomy fixation for thoracolumbar fracture combined with spinal cord compression obtained better outcomes, and could obviously relieve spinal cord compression. Posterior laminectomy fixation isasafe and effective treatment method for thoracolumbar fracture and spinal cord compression.
ABSTRACT
BACKGROUND:In recent years, with the development of minimaly invasive techniques, the application of percutaneous pedicle screw fixation techniques gradualy become widespread, but in the percutaneous pedicle screw fixation for thoracolumbar fractures, due to lack of reduction apparatus or power defect, the reduction of the injured vertebra is poor. In order to improve this deficiency, we design a percutaneous pedicle screwsystem in order to achieve the desired effect of reduction. OBJECTIVE:To investigate the two different effects for treating unstable thoracolumbar fractures by fixing RTS (rotation softened trauma fixation system) or SEXTANT screws under minimaly invasive technology. METHODS:From October 2011 to June 2013, 50 patients who suffered from single-segment thoracolumbar fractures without any nerve-injured symptoms were treated by using percutaneous pedicle screws. Among them, 25 cases used Sextant screws; the others used RTS screws. Data were compared between the two groups, including the height of injured vertebrae, Cobb’s angle, visual analogue scale scores and Oswestry disability index 1 week, 3 and 6 months postoperatively, and during final folow-up. RESULTS AND CONCLUSION:(1) Al patients were folowed upfor8-18 months. (2) The height of injured vertebrae and Cobb’s angle were restored in both groups, showing significant differences (P<0.01). The restoration of the height of injured vertebrae and Cobb’s angle was better in the RTS group than in the SEXTANT group after treatment (P< 0.05-0.01). (3) The visual analogue scale scores and Oswestry disability index were significantly better in the RTS group than in the SEXTANT group 6 months postoperatively and during final folow-up (P< 0.05). (4) These results suggest that both RTS and SEXTANT systems can effectively repair single-segment thoracolumbar fractures without any nerve-injured symptoms. However, it is clear that the recovery of the height ofthe vertebral body is more satisfied and the postoperative pain and dysfunctionweremore minor in the RTS group.
ABSTRACT
BACKGROUND:Sagittal imbalance induced by vertebral osteoporotic fractures has not been paid enough attention in previous studies. OBJECTIVE:To assess the correlation of osteoporotic vertebral compression fracture and spinal sagittal imbalance. METHODS:Sixty patients with old osteoporotic vertebral compression fracture, who were treated in the Department of Spine Surgery, the Affiliated Hospital of Chengde Medical Colege from February 2013 to August 2015, were enroled in this study as the observation group. Sixty healthy old people from physical examination center were enroled as the control group. The whole-spine anteroposterior and lateral X-ray films were taken in both groups. The number and the location of fractured vertebrae were recorded. Sagittal parameters of both groups including thoracic kyphotic angle, lumbar lordotic angle, T1-spinopelvic inclination angle and the C7plumb line/sacro-femoral distance (PL/SFD) ratio were measured and compared among groups. The observation group was dividedinto three subgroups according to the number of fractured vertebrae,i.e., single-vertebrae fracture subgroup, double-vertebrae fracture subgroup and above triple-vertebrae fracture subgroup. The C7PL/SFD ratio of the three subgroups was compared. The correlation between the number of fractured vertebrae and the C7PL/SFD ratio was analyzed. RESULTS AND CONCLUSION:(1) The thoracic kyphotic angle of the observation group was bigger than that of the control group (P< 0.05). The lumbar lordotic angle of the observation group was smaler than that of the control group (P< 0.05). The absolute value of the T1-spinopelvic inclination angle of the observation group (-1.81±1.48)° was smaler than that of the control group (-3.35±1.22)° (P< 0.05). The C7PL/SFDratio of the observation group was significantly bigger than that of the control group (P< 0.05). (2) In the observation group, there were 4 cases of single-vertebrae fracture, 25 cases of double-vertebrae fracture and 31 cases of above triple-vertebrae fracture. Significant differences in the C7PL/SFD ratio were determined among subgroups (P< 0.05). The number of fractured vertebrae was positively correlated with the C7PL/SFD ratio; the correlation coefficient was 0.747. (3) Results indicated that osteoporotic vertebral compression fracture can change spinal local sagittal alignment. Multiple compression fractures of vertebrae can cause spinal sagittal imbalance. The gravity center of human body shifts forward. The number of fractured vertebrae was positively correlated with the range of shift forward.