椎动脉高跨和颈2椎板螺钉.ppt

椎动脉高跨和颈椎动脉高跨和颈2椎板螺钉椎板螺钉（High-Riding Vertebral Artery/C2 laminar screws）俞武良 2018-3-21 C2 pedicle screw vertebral artery(VA)VA injury 4.1%to 8.2%for posterior atlantoaxial transarticular screw fixation 5.3%21%for C2 pedicular screw Factors contribute to VA injury VA groove(VAG)anomaly high-riding vertebral artery 14.5%18%narrow C2 pedicle 9.5%32%insertion of the screw extremely close to the VA HRVAHRVA defined as having an isthmus height of 5 mm and/or an internal height of 2 mm on the sagittal image 23 mm lateral to the cortical border of the spinal canal at C2.narrow C2 pedicle defined as having the largest pedicular width of 4 mm on the axial image high-riding vertebral artery(HRVA)椎动脉在枢椎上关节突的下方有一个向外的弯曲,如果椎动脉弯曲过于向后、内或位置过高,则提示枢椎峡部狭窄,这种情况称为椎动脉高跨 C2 laminar screw(Wright 2004)我们最近的病例我们最近的病例