The current study is developed based on one of the types of subgrade rupture risk suggested by Selig and Waters （1994）. It aims to evaluate subgrade stability railroad, which consists of the slope stability analysis...The current study is developed based on one of the types of subgrade rupture risk suggested by Selig and Waters （1994）. It aims to evaluate subgrade stability railroad, which consists of the slope stability analysis of a railway yard embankment subjected to a wagon load type gondola parked on this track. This proposed analysis was taken into consideration because there are Brazilian railroads in high deterioration level. In some of these lines the tracks are submitted to increasing amount of load every year. The adopted model slope stability to the studied railroad embankments considers the rupture on circular line. It was applied the Geoslope-Slope/W software, version 6, to the evaluation of the platform-slope system. Several situations are adopted to reach the minimum safety slope, permitting to analyze the platform stability to keep railroad traffic under adequate safety level.展开更多
Objective： To explore the safety and effect of the technique of reconstructing anterior and middle columns by posterior approach in treating lumbar burst fractures. Methods： From July 2005 to January 2007, 22 cases ...Objective： To explore the safety and effect of the technique of reconstructing anterior and middle columns by posterior approach in treating lumbar burst fractures. Methods： From July 2005 to January 2007, 22 cases （18 males and 4 females, aged 28-57 years, 42.7 years on average） of lumbar burst fractures were treated with surgical procedures in our hospital. Based on the routine posterior approach, one of the transverse processes of the injured vertebra was incised to get access to the lateral side of the injured vetebral body. After all the displaced fracture fragments were cleared away and the spinal canal was decompressed, the titanium mesh packed with autografts was implanted from the lateral side to reconstruct the anterior and middle columns. The adjacent above and below segments of the vetebral body were fixed with transpedicular screws. The operation time, intraoperative blood loss, vertebral height, degree of kyphotic deformity and comprised spinal canal were documented. Results： The average operation time was 3.5 hours （ranging 2.8-5.8 hours） and the average blood loss was 820 ml （ranging 650-2 100 ml）. All the cases were followed up for 17.2 months on average （ ranging 12-28 months）. The height of the injured vetebral body was restored from 24 % （12%- 45%） preoperatively to 96% （95%-99%） postoperatively （P〈0.05）. The natural spinal curvatures and spinal canal were restored. Three cases were involved in transient iatrogenic nerve root injury and 1 case was involved in the loosening of the connected rod of the pedicle screw system 3 months postoperatively. Conclusions： The technique of implanting the titanium mesh by posterior approach is effective and safe enough to reconstruct the anterior and middle columns in treating lumbar burst fractures.展开更多
文摘The current study is developed based on one of the types of subgrade rupture risk suggested by Selig and Waters （1994）. It aims to evaluate subgrade stability railroad, which consists of the slope stability analysis of a railway yard embankment subjected to a wagon load type gondola parked on this track. This proposed analysis was taken into consideration because there are Brazilian railroads in high deterioration level. In some of these lines the tracks are submitted to increasing amount of load every year. The adopted model slope stability to the studied railroad embankments considers the rupture on circular line. It was applied the Geoslope-Slope/W software, version 6, to the evaluation of the platform-slope system. Several situations are adopted to reach the minimum safety slope, permitting to analyze the platform stability to keep railroad traffic under adequate safety level.
文摘Objective： To explore the safety and effect of the technique of reconstructing anterior and middle columns by posterior approach in treating lumbar burst fractures. Methods： From July 2005 to January 2007, 22 cases （18 males and 4 females, aged 28-57 years, 42.7 years on average） of lumbar burst fractures were treated with surgical procedures in our hospital. Based on the routine posterior approach, one of the transverse processes of the injured vertebra was incised to get access to the lateral side of the injured vetebral body. After all the displaced fracture fragments were cleared away and the spinal canal was decompressed, the titanium mesh packed with autografts was implanted from the lateral side to reconstruct the anterior and middle columns. The adjacent above and below segments of the vetebral body were fixed with transpedicular screws. The operation time, intraoperative blood loss, vertebral height, degree of kyphotic deformity and comprised spinal canal were documented. Results： The average operation time was 3.5 hours （ranging 2.8-5.8 hours） and the average blood loss was 820 ml （ranging 650-2 100 ml）. All the cases were followed up for 17.2 months on average （ ranging 12-28 months）. The height of the injured vetebral body was restored from 24 % （12%- 45%） preoperatively to 96% （95%-99%） postoperatively （P〈0.05）. The natural spinal curvatures and spinal canal were restored. Three cases were involved in transient iatrogenic nerve root injury and 1 case was involved in the loosening of the connected rod of the pedicle screw system 3 months postoperatively. Conclusions： The technique of implanting the titanium mesh by posterior approach is effective and safe enough to reconstruct the anterior and middle columns in treating lumbar burst fractures.
