骶骨后路钉板固定的解剖学研究

Anatomic study of dorsal plate-screw fixation in sacral fractures

目的探讨骶骨横行或斜行骨折时钉板固定的安全性。方法30具新鲜成人尸体标本，男15具，女15具；年龄38~82岁，平均65岁。在骶骨上做标记：O点为骶骨螺钉进钉点（O1点位于关节突关节的外下缘，O2和O3点位于经相邻骶后孔连线中点的水平线与骶外侧嵴的交点，O。点位于S，、S。骶后孔连线的中点至骶外侧嵴水平线的中点），D1为骶骨内侧置钉钉道长度，D：为骶骨垂直置钉钉道长度，D，为骶骨外侧置钉钉道长度，d为骶骨横截面上内侧置钉最大偏移角度，8为骶骨横截面上外侧置钉最大偏移角度。结果S，的D。、D2、D3、d，B值分别为（38．73±5．29）mm、（31．15±4．68）mm、（41．47±6．18）mm、31．88°±4．32°、34.31°±5．12°；S2的D1、D2、D3、d，B值分别为（28．53±2．19）mm、（23．95±2．59）mm、（34．69±5．13）mm、14．70°±3．54。、20．48°±5．35°；S3的D1、D2、D3、OL，B值分别为（30．62±3．15）mm、（17．18-±3．51）mm、（24．66±5．13）mm、52．00°±7．55°、39．00°±5．50°；S4的D1、D2、D3、仅，B值分别为（23．21±4．14）mm、（9．07±2．20）mm、（14．52±3．51）mm、18．47°±4．42°、10．23°±2．69°。结论Sl螺钉在O1点进钉，平行于k棘突是理想的置钉路径。S2-S4理想的置钉路径：S2螺钉在02点进钉，横截面上偏向外侧小于20.48°±5．35。；S3螺钉在O3点进钉，横截面上偏向内侧小于52．00°±7．55°；S4螺钉在O4点进钉，横截面上偏向内侧小于18．47°±4．42°。

Objective To explore the security of dorsal plate-screw fixation in transverse or oblique sacral fractures. Methods Thirty fresh adult corpses （15 males and 15 females, the age ranged from 38 to 82 years, mean 65 years） were studied. The points of sacrum were separately defined as： label point on the sacrum of 30 cases of pelvic specimen were made and the points of sacrum were separately defined as： O points was the entry point of the sacral screw; D° was the screw trajectory＇s length when fixing to the medial; D2 was the screw trajectory＇s length when vertical fixing; D3 was the screw trajectory＇s length when fixing to the lateral;α was the maximum deviation angle of sacrum at cross-section when fixing to the medial; β was the maximum deviation angle of sacrum at cross-section when fixing to the lateral. Results For the S1 screw, the average values of D°,D2, D3,α and β were （38.73±5.29） mm, （31.15±4.68） mm, （41.47±6.18） mm, 31.88°±4.32° and 34.31°±5.12° respectively. For the S2 screw, the average values of D1, D2, D3, α and β were （28.53±2.19） mm, （23.95±2.59） ram, （34.69±5.13） ram, 14.70°±3.54° and 20.48o±5.35° respectively. For the $3 screw, the average values of D l, D2, D3, α and β were （30.62±3.15） mm, （17.18±3.51 ） mm, （24.66±5.13） mm, 52.000±7.55° and 39.000±5.50° respectively. For the $4 screw, the average values of DI, D2, D3, α and β were （23.21±4.14） mm, （9.07±2.20） mm,（14.52±3.51） ram, 18.47°±4.42° and 10.23°± 2.69° respectively. Conclusion It is the optimal trajectory for S1 screw to entry at O1 points, and be parallel to L5 spinous process. The S2, S3 and S4 screw＇s entry points respectively are O2, O3 and 04 points and the screw placement parallel to the upper endplate at sagittal plane. The optimal screw placement at cross-sec- tion is leaned to lateral less than 20.48°±5.35° for S2 screw, leaned to medial less than 52.000±7.55° for S3 screw, and to lateral less than 18.47°±4.42° for S4 screw respectively.