1991 Fiscal Year Final Research Report Summary
Titanium fiber metal as a biomaterial implanted for spine fusion
| Project/Area Number |
01480370
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Orthopaedic surgery
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| Research Institution | Kochi Medical School |
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Principal Investigator |
YAMAMOTO Hiroshi Kochi Medical School, Department of Orthopaedic Surgery, Professor, 医学部, 教授 (90035709)
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| Co-Investigator(Kenkyū-buntansha) |
KAMIOKA Yoshihiko Kochi Medical School, Department of Orthopaedic Surgery, Associate Professor, 医学部, 講師 (60185981)
TANI Toshikazu Kochi Medical School, Department of Orthopaedic Surgery, Associate Professor, 医学部, 助教授 (90136250)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Biomaterial / Titanium / Porous Material / Mechanical Property / Biomechanics / implant / Spine Fusion / Biotolerance |
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| Research Abstract |
Since 1985, we have developed a favorable biomaterial of titanium fiber metal implant (T. F. M. I.) for anterior spine fusion. The material is made of pure titanium wire of 250 mum diameter woven into mesh and sintered. Compression testing showed that failure stress and modulus of elasticity of this implant more closely resemble those of cancellous bone of vertebrae. And that this material showed reversible strain to the compression stress. Titanium fiber metal implants (8mmx 8mm x5mm) were implanted anteriorly into the lumbar intersegmental space of 16 adult dogs. To provide enough initial fixation, anterior tension band wiring was added at the time of surgery. A periodic observation of the radiological change at the interface of the implant and the bone were carried out. Toluidine-blue stained hard tissue specimens of the implant and the bone were made, and the biological fixation of the implant was evaluated at 1, 3, 6, 9 and 12 months post implantation. Biomechanical fixation of the enplant was measured by the push-out test. After the implantation, radiolucent zone appeared around the implant in all dogs. It was a wide and fuzzy zone, and its margin was unclear. Until the postoperative 3 months, radiolucent zone was noticed around the implant. Then, the abnormal shadow gradually disappeared. One hundred) lm hard tissue specimen by toluidine-blue staining of the animal without any radiolucent area revealed travecular bone formation in the space of the titanium wire. As time passes, the new travecular bone had been gradually growing into the enplants. And at post operative 12 months, the maximum depth of the bone ingrowth was 2.35mm. As time passes, the force to push out had increased. And at 9 months after the implantation, the maximum shearing force of the bone-implant interface was 49.2 kgf/cm_2. These favorable experimental results give us an assurance of the clinical use of this implant as an excellent biomaterial for spine fusion.
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