新型防神经根损伤双螺纹椎弓根螺钉解剖学依据

Anatomical basis of a new double-threaded pedicle screw for preventing nerve root injury

目的通过测量正常人双侧的胸椎及腰椎椎体解剖学参数,为新型防神经根损伤双螺纹椎弓根螺钉的设计提供理论依据。方法纳入200例健康志愿者,在仰卧位CT片上测量胸椎T1~12及腰椎L1~5椎弓根螺钉进钉路径的分段长度(椎体段、椎弓根段和椎板段)、进钉外展角及椎弓根峡部宽度和高度。计算各解剖参数的均值和标准差。结果纳入胸椎志愿者100人,平均年龄31.21岁,腰椎志愿者100人,平均年龄31.05岁。胸椎组螺钉椎体段长度为左侧(19.09±2.36)mm,右侧(19.77±2.54)mm;螺钉椎弓根段长度为左侧(7.67±1.19)mm,右侧(8.17±1.16)mm;螺钉椎板段长度为左侧(9.94±2.02)mm,右侧(9.06±1.71)mm;进钉外展角为左侧(8.61±2.57)°,右侧(8.44±2.71)°;椎弓根峡部宽度为左侧(8.44±2.71)mm,右侧(5.95±1.16)mm;椎弓根峡部高度为左侧(11.76±1.86)mm,右侧(11.79±2.24)mm。腰椎组螺钉椎体段长度为左侧(26.99±3.37)mm,右侧(27.06±3.24)mm;椎弓根段长度为左侧(10.00±1.58)mm,右侧(10.37±1.53)mm;椎板段长度为左侧(12.74±2.16)mm,右侧(13.96±2.46)mm;进钉外展角为左侧(16.16±2.93)°,右侧(16.31±3.05)°;椎弓根峡部宽度为左侧(9.72±1.59)mm,右侧(9.45±1.84)mm;椎弓根峡部高度为左侧(14.50±2.83)mm,右侧(14.05±2.39)mm,胸椎与腰椎螺钉椎体段长度、椎弓根段长度、椎板段长度、进钉外展角各参数对比,差异无统计学意义(P>0.05),T1~L5椎弓根峡部高度分别与椎弓根峡部宽度比较,有统计学差异(P<0.05)。结论通过对正常人群胸椎及腰椎椎骨较为细致的相关解剖学测量,可获得设计新型双螺纹椎弓根螺钉的较准确依据。

Objective To provide the anatomical basis of a new double-threaded pedicle screw for reducing the incidence of nerve root injury,by measuring the anatomical parameters of thoracic and lumbar vertebrae.Methods Two hundred healthy volunteers were included for the thoracic and lumbar spine CT scan.The following parameters were measured on CT films:the segment lengths of pedicle screw entry path(the length of the vertebral body,the pedicle and the lamina),the height of the pedicle isthmus,the pedicle isthmus and the angle of the screw abduction.The mean and standard deviation of each parameter were calculated.Results A total of 100 thoracic volunteers with an average age of 31.21 years old and 100 lumbar volunteers with an average age of 31.05 years old were included.Parameters of the thoracic group were as follows:the length of the vertebral body was left(19.09±2.36)mm,right(19.77±2.54)mm,the length of the pedicle was left(7.67±1.19)mm,right(8.17±1.16)mm,the length of the lamina was left(9.94±2.02)mm,right(9.06±1.71)mm,the height of the pedicle isthmus was left(11.76±1.86)mm,right(11.79±2.24)mm,the width of the pedicle isthmus was left(8.44±2.71)mm,right(5.95±1.16)mm,the angle of the screw abduction was left(8.61±2.57)°,right(8.44±2.71)°.Parameters of the lumber group were as follows:the length of the vertebral body was left(26.99±3.37)mm,right(27.06±3.24)mm,the length of the pedicle was left(10.00±1.58)mm,right(10.37±1.53)mm,the length of the lamina was left(12.74±2.16)mm,right(13.96±2.46)mm,the height of the pedicle isthmus was left(14.50±2.83)mm,right(14.05±2.39)mm,the width of the pedicle isthmus was left(9.72±1.59)mm,right(9.45±1.8)mm,the angle of the screw abduction was left(16.16±2.93)°,right(16.31±3.05)°.There was no statistical differences on the length of the vertebral body,pedicle,lamina and the angle of the screw abduction between the thoracic and the lumbar groups at the same segment(P>0.05).There were statistical differences on the pedicle isthmus height from T1 to L5 and pedicle isthmus width between the two groups(P<0.05).Conclusions Detailed anatomical measurements of the thoracic and lumbar vertebrae in healthy subjects can provide more accurate basis for the design of a new double-threaded pedicle screw.