| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1987: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1986: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Research Abstract |
The bone grafts for anterior spine fusion are well recognized to have some problems such as the mechanical failure, the prolonged time of immobilization, and the bone resource. There, however, was no favorable biomaterials to be available for the patients with non-tumorous conditions.
To serve as a graft in spine fusion, a sintered titanium fiber metal implant(TFMI) of a woven pure titanium wire 250<micrn>m in diameter was studied for its mechanical properties and biological fixation.
Compression testing showed that the failure stress and modulus of elasticity of our implant more closely resembled those of the cancellous bone of the vertebrae than the previously reported fiber metals did. Within the range of ultimate strain rate of cancellous bone, this material demonstrated reversible strain to the compression stress. Furthermore, it was found that the pore-size distribution and the mechanical properties of our TFMI were less variable than those of the products of kinked-and-cut-wires.
Repetitive-loading test of ten-million times of compression and decompression, even with loads much greater than the failure stress of the vertebral body, showed a low permanent strain rate.
Histologically and biomechanically, sufficient bone ingrowth and biological fixation was observed in the TFMI implanted lumbar vertebrae of adult mongrel dogs. At the time of 24 week after implantation, maximum bone ingrowth was 2.12mm form the surface of the implant and at four week after implantation, average shear stress of the bone-implant interface was 0.79MPa in three samples.
According to these favorable experimental results, a new implant of RFMI could be utilized clinically as an excellent biomaterial for spine fusion.
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