新型空心钉导针定位器的研制及其在股骨颈骨折模型中的应用

Designs of a novel drill guide of hollow screw placement and applications in a synthetic bone model of femoral neck fractures

目的研制一种应用于股骨颈骨折空心钉内固定的导针定位系统。方法设计一种术中可透视可调节的空心钉导针定位器,在导针置入前即可评估其进针点和方向,以使导针在股骨颈内合理分布。在股骨颈标本中分别采用徒手导针定位(徒手定位组)、普通导针定位器定位(普通定位组)及新型导针定位器定位(新型定位组)下行3枚空心钉内固定。比较3组的重复置钉率、股骨颈标本截面中孔距间面积比、正侧位X线片中螺钉相互平行度及骨折内固定标本最大垂直承重载荷。结果新型定位组孔距间面积比(0.11±0.03)大于普通定位组的(0.10±0.03),普通定位组大于徒手定位组的(0.09±0.05),差异有统计学意义;徒手定位组正、侧位X线片中螺钉相互平行度[(1.47±0.46),(2.78±0.47)]均大于普通定位组[(0.61±0.84),(1.19±0.55)]和新型定位组[(0.48±0.63),(0.98±0.60)],差异有统计学意义,但普通定位组与新型定位组差异无统计学意义;新型定位组重复置钉率(133±37)%小于徒手定位组(344±109)%和普通定位组(267±70)%,差异有统计学意义,但徒手定位组与普通定位组差异无统计学意义;3组最大承重载荷相当,差异无统计学意义。结论新型股骨颈空心钉导针定位器克服了传统导针定位的不足,可为螺钉提供准确、快速的导针定位。

Objective To design a new type guiding system and explore its value in treatment of femoral neck fracture with hollow screws. Methods The new type guiding system for screw placement was designed with adjustable and radiotmnsparent advantages, which could make certain correct entry point and direction of guide pin before drilled into femoral neck to ensure reasonable distribution of guide pin in femoral neck. Three guiding methods, including freehand guiding, conventional guiding and novel guiding were respectively applied into femoral neck fracture fixation. Repeating drilling ratio was recorded in process of drilling guiding pins. Parallelism and spread area ratio of three guide pin in the femoral neck were measured and compared according to radiography and cross section of femoral neck and maximum vertical loading was tested. Results The spread area ratio was （0.11±0.03） in novel guiding group, （0.10±0.03） in conventional guiding group and （0.09±0.05） in freehand guiding group, with significant differences among three groups. Parallelism in AP and lateral view of freehand guiding group [（1.47±43.46）, （2.78±0.47）] was significantly higher than those of conventional guiding group [（0.61±0.84）, （1.19±0.55）] and novel guiding group [（0.48±0.63）, （0.98±0.60）], with no significant difference between latter two groups. Repeating drilling ratio of novel guiding group （133±37）% was significantly lower than freehand guiding group （344±109）% and conventional guiding group （267±70）%. Maximum vertieal loading was similar among three groups with no significant difference. Conclusion Novel serf designed guiding of screw fixation for femoral neck fractures is able to provide accurate and quick guiding, while overcomes shortage of usual methods of guiding for screws.