| Project/Area Number |
13671531
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Orthopaedic surgery
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| Research Institution | Tokyo Women's Medical University (2002)
Kyoto Prefectural University of Medicine (2001) |
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Principal Investigator |
NOGUCHI Masahiko Tokyo Women's Medical University, Dept. of Orthop. Surg., Associate Professor, 医学部, 助教授 (60208329)
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| Co-Investigator(Kenkyū-buntansha) |
CHIBA Junji Tokyo Women's Medical University, Dept. of Orthop., Associate Professor, 医学部, 助教授 (90211375)
SEO Yoshiteru Kyoto Pref. University, Dept. of Phys., Professor, 医学部, 講師 (90179317)
KUSAKA Yoshiaki Asahi University, Dept. of Orthop. Surg., Professor, 歯学部, 教授 (40205068)
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| Project Period (FY) |
2001 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2002: ¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 2001: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Achilles tendon / Water Molecule / DQF NMR / Collagen Fiber / Stress-shielding / Anisotropy / Dynamic Viscoelasticity / MRI |
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| Research Abstract |
The effects of stress-shielding on the viscoelastic properties and micro-structure of collagen fibers in the Achilles tendon were investigated. The right hind-limb of twenty Japanese white rabbits were immobilized for four weeks in a cast with the ankle in plantarflexion. Bilateral Achilles tendons were dissected and the right Achilles tendon was used as a stress-shielding model (ss group). The left Achilles tendons served as controls (control group). Dynamic viscoelasticity of the Achilles tendons of the both groups was measured to determine dynamic storage modulus (E') and dynamic loss modulus (E''). Proton Double-Quantum Filtered (^1H-DQF) NMR signals were analyzed to determine the residual dipolar coupling of bound water molecules in the Achilles tendons. This is a quantitative indicator of the degree of longitudinally ordered structures in the collagen fibers. Both the E' and E'' decreased significantly in the Achilles tendons of the ss group. We assume that the decreases may be attributable to the disordered structure of the longitudinally aligned collagen fibers in the Achilles tendons of the ss group. The results of the ^1H-DQF NMR examination demonstrated significantly reduced residual dipolar coupling in the Achilles tendons of the ss group. These findings support the hypothesis that stress-shielding may result in disordering of the collagen fibers, which may in turn account for the changes in viscoelastic properties.
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