髋臼骨折内固定的置钉安全研究

Investigation of Proper Screw Placement for Internal Fixation for Acetabular Fractures

探讨髋臼骨折内固定危险区域安全置钉的方法,降低螺钉穿入髋关节的风险。取得173例正常成人完整骨盆CT断层扫描数据,由此建立清晰完整的三维数字化骨盆模型,对其进行由耻骨联合到骶髂关节方向的曲线拟合,并在髋臼区域等分此曲线,获得垂直曲线的5个截面。以过进钉点并垂直于骨表面的截面曲线法向面作为参考平面,测量不同截面的进钉角度范围（α~γ）及对应的进钉深度d1、d2、d0;比较男性、女性之间存在的差异,综合手术入路的可行性,对髋臼区螺钉植入进行安全规划。结果表明,截面2的d0,截面3的β、γ以及截面4的β,在男性和女性之间的差异具有统计学意义（P〈0.05）;安全进钉角度范围与手术入路可行范围存在部分交集。临床髋臼区域下缘置钉时要考虑到男、女性别不同所产生的差异;截面1和截面5置钉方向比较自由;截面4安全置钉角度接近可操作临界角度,临床上置钉应避开截面2和截面3。

This study is aimed to investigate proper screw insertion angles and lengths of internal fixation for acetabular fractures, reducing the danger of screw penetration into the hip joint. Complete peivic CT scan data from 173 normal adults were collected. Each adult＇ s CT scan data were reconstructed into a 3D digital pelvic model. A curve was delineated from the pubic tubercle to the sacroiliac joint to simulate the fixation rout, according to which five perpendicular cross-sections were constructed equally across the acetabular region. The normal plane, going through the screw-entry point and perpendicularly to the bone surface, was selected as the reference plane for each cross-section. Hence the safe screw angles （a - Y） and lengthes （d~, d2, d0） were measured. Proper screw placements were obtained within sex differences and operation feasibilities. Safe length do from section 2, safe angles ~ and Y from section 3 and safe angle /3 from section 4 showed significant sex differences （P 〈 O. 05 ）. There are proper ranges of safe screw insertion angles for operation. Sex differences should be considered during internal fixation operations on the inferior border for acetabular fractures. Screw placements could be much more flexible on section 1 and section 5. The safe screw insertion angles on section 4 was close to the critical angles for operation. Screws are not recommended to be placed on section 2 or section 3.