28-第一跖跗关节骨折脱位三种内固定对骨面应力传导变化的生物力学研究 二院 余霄.doc

第一跖跗关节骨折脱位固定骨应力的研究 余 霄俞光荣 [摘要]目的: 测量第一跖跗关节骨折脱位内固定骨面应力变化，为选择内提供参考。方法: 取具新鲜足标本，第一跖跗关节骨折脱位模型，依次进行3.5mm全螺纹皮质骨螺钉，1/4管型钢板及加压骑缝钉固定。加载600N，通过电阻应变片法测量第一跖骨基底及内侧楔骨的应变。男性志愿者1名，经有限元建模软件建立第一跖跗关节骨折脱位并钢板N加载，观察内固定上的应力分布。结果：第一跖跗关节骨折脱位分别进行螺钉，钢板及骑缝钉固定后，第一跖骨基底及内侧楔骨的应都减小其中，钢板与螺钉固定的应较骑缝钉固定的应更小，差异有统计学意义（P＜0.05）。结论：第一跖跗关节骨折脱位引起传导障碍从角度看，钢板或螺钉固定表现出较明显的应力遮挡效应，有利于骨折脱位的早期愈合但负重[关键词] 跖跗关节，骨折脱位，内，应力生物力学 The Stress Conduction changes of the First Tarsometatarsal Joint Fracture-Dislocation F by Three Different Internal Implants: A Biomechanical Study [Abstract]: Objectives: To measure the changes of stress conduction on the first tarsometatarsal joint fracture-dislocation by three different implants to provide reference in selecting implants. Methods: Six fresh foot specimens were made into the models of the first tarsometatarsal joint fracture-dislocation, which were fixated with 3.5 mm cortical screw, 1/4 tubular plate and compressive staple in turn. After 600N loading, the strain at the base of the first metatarsal and the medial cuneiform was measured by the resistance strain gauge. In addition, one healthy male volunteer was recruited and the first tarsometatarsal joint fracture-dislocation model was established by the finite element software. The fixation of screw, plate and staple were simulated under the 600N loading to observe the stress distribution of implants. Results: After the fixation of the first tarsometatarsal joint fracture-dislocation by screw, plate and staple respectively, the stress was reduced at the base of the first metatarsal and the medial cuneiform, among which the stress by plate and screw become smaller than by staple and the difference was statistically significant(P＜0.05he finite element analysis demonstrated that the stress of screw fixation was the most centralized and showed higher stress in the middle part; on the contrary, the stress of plate and staple was decentralized and the highest stress was also smaller than that of screw. Conclusions: The