第三、四骶骨螺钉应用的解剖学研究

目的通过对第三、四骶骨螺钉应用的解剖学测量,探讨第三、四骶骨螺钉应用的安全性。方法 32具成人骶骨标本。设定A点、B点和C点为螺钉进钉点,分别位于相邻骶后孔内侧缘连线的中点,相邻骶后孔连线的中点,经相邻骶后孔连线中点的水平线与骶外侧嵴的交点。D1、D2、D3、α和β、分别为水平面上骶骨内侧置钉,垂直置钉和外侧置钉的钉道长度,内侧置钉和外侧置钉最大偏移角度。d1、d3、θ和φ分别为矢状面上骶骨头侧置钉和尾侧侧置钉钉道长度,头侧置钉和尾侧置钉最大偏移角度。结果 S3螺钉在A和B点进钉,水平面上偏向外侧小于45.21°±10.66°,矢状面上偏向头侧小于8.50°±3.53°;C点进钉,水平面上偏向内侧小于52.00°±7.55°,矢状面上偏向头侧小于19.05°±6.36°。S4螺钉在A和B点进钉,水平面上偏向外侧小于49.50°±9.53°,矢状面上偏向头侧小于12.00°±4.24°,偏向尾侧小于14.00°±2.83°;C点进钉,水平面上偏向内侧小于66.19°±8.14°,矢状面上偏向头侧小于13.50°±3.54°,偏向尾侧小于28.50°±2.12°。结论了解第三、四骶骨的解剖结构和精确的螺钉放置可以保证骶骨螺钉固定成功。

The anatomic study on the third and fourth sacral screw

Objective To explore the security of the third and fourth sacral screw fixation through the anatomic measurement of the third and fourth sacral vertebra.Methods The structure and contour of the third and fourth sacral vertebra were observed in 32 adult sacrum specimens.The designed entry points were A、B and C.The A point was at the midpoint between the most medial margin of the superior foramina and the most superior margin of the inferior foramina.The B point was at the midpoint between the adjacent foramina and the C point was a crosspoint of the line from the B point horizontally toward the lateral sacral crest.The lengths of the sacral screw tunnel of the left,right,up and down sides passing through the median zone of the sacrum,the lengths of the vertical trajectory,and the length of the sacral tunnel of both sides through the lateral zone of the sacrum on the sagittal and horizontal planes,and the length of the sacral tunnel of both sides through the lateral zone of the sacrum on the sagittal and sagittal planes were D1,D2,D3,d1 and d3 respectively.The deviation angles of the sacral screw passing through the medial zone of the vertebra and the deviation angles of the sacral screw passing through the lateral zone of the both sides vertebra on the sagittal and horizontal and sagittal planes were α,β,θ and φ respectively.Results At the third sacral vertebra,if the entry points were A or B.The value of β andθwere(45.21±10.66)°and(8.50±3.53)°.If The entrying points were C,the values ofα andθ were(52.00±7.55)°and(19.05±6.36)°.At the fourth sacral vertebra,if the entry points were A or B,the values of β,θ and φ were(49.50±9.53)°(12.00±4.24)°and(14.00±2.83)°.If the entry point were C,the values of θ and φ were(13.50±3.54)°和(28.50±2.12)°.Conclusion Understanding of the anatomic structure and the precisely installed location of the screw can ensure the successful fracture fixation of third and fourth sacral screw.