RESUMO
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.
RESUMO
[Objective]To evaluate outcome of the treatment of unstable distal radius fractures in the elderly patient using a volar T-shape plate.[Method]From January 2001 to April 2003,42 cases with unstable distal radius fractures older than 60 years(range 60～75 years;mean age 65.1 years) were treated with a T-shape plate fixation.The fractures were classified according to the AO classification of distal radius fracture: 4 A2,7 A3,5 B1,3 B3,9 C l,11 C2,3 C3.Artificial bone graft substitutes were used in 28 cases with severe cortex destruction and insufficient buttress.[Result]All patients were followed up(mean 18.2months,range 12～24months).Final volar tilt was averaged 3.66? and radial tilt 20.1?,and radial shortening averaged 1.59 mm in 6 cases.Step-off or gap of the articular surface was found in 6 cases(mean
