Biomechanical evaluation of an injectable calcium phosphate cement incorporating DHS for osteoporotic intertrochanteric fracture:an in vitro study / 医用生物力学

ABSTRACT

Objective To evaluate the biomechanical effects of using a new injectable calcium phosphate cement to consolidate the fixation of osteoporotic intertrochanteric fracture.Method Five matchod pairs of human cadaver femora were used to produce the model of intertrochanteric fracture.All fractures were fixed with dynamic hip screws(DHS),and divided into two groups.In the CPC consolidation group of each pair,CPC was used to grout the hip screw and to fill the posteromedial defect.All femora were subjected to biomechanical test.Results Under the loading of 500 N,in the CPC consolidation group,the mean axial stiffness is(691.93±18.90)N/mm and the horizontal shear stiffness is(5553.84±27.47)N/mm.The mean lateral and medial strength is(5.15±0.35)MPa and(4.13±0.24)MPa.The torsion stiffness was 0.41 and the ultimate loading is(3580±286)N.In the control group,the mean axiak stiffness is(453.45±19.75)N/mm,the horizontal shear stiffness is(3848.87±22.63)N/mm,the mean lateral and medial strength is(3.12±0.37)MPa and(1.80±0.21)MPa,and,the torsion stiffness is 0.35 and the ultimate loading is(2512±189)N.Consolidation fixation with CPC increased each of the biomechanical efficiency(P＜0.05).Conclusions CPC consolidation of osteoprotic femoral head and the medial defect of intertrochanteric fracture can significantly improve the overall stability and decrease the rate of postoperative complication.