Biomechanical study of improved memory alloy embracing fixators in treatment of periprosthetic femoral fracture due to hip arthroplasty / 中华创伤杂志

ABSTRACT

Objective To study the mechanics of improved memory alloy fixators for salvage of periprosthetic femoral fracture (PFF) after hip arthroplasty in the elderly.Methods Thirty countrymen fresh cadaveric femurs with no pathological defect,fracture,deformity or tumor were randomly divided into experimental group and control group with 15 femurs in each according to the random number table.A model of Vancouver type B1 periprosthetic femoral fracture following hip arthroplasty was induced.The fracture was treated with modified memory alloy embracing fixators in experimental group;instead general memory alloy embracing fixators in control group.All specimens were tested biomechanically.Results Under the same mechanical loading,the two groups showed respective 30％ and 48％ maximum differences in stress value and displacement.Results in three-point bending test did not differ significantly between the two groups (P ＞ 0.05),but there were significant differences in axial compression and torsion test (P ＜ 0.05 or 0.01).Conclusion The improved memory alloy embracing fixators present better resistance to compression and torsion compared to the general fixators.