| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2002: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
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| Research Abstract |
We studied maturation and strength of bone during distraction osteogenesis in callotasis. Under general anesthesia, a longitudinal skin incision was made of the lateral aspect of the femur to expose femoral shaft. Four self -tapping screws were placed at right angles to the longitudinal axis of the femoral shaft. The screws were clamped to the external fixator. After that, transverse osteotomy was done between 3rd and 4th screws using a hand saw. Distraction started 7 days after operation at a rate of 0.25 mm every 12 hours (0.5mm/day) for 21 days. Biophysic analysis, measurement of bone strength and bone mineral density were performed just after 21 days of distraction, 3 weeks, 6 weeks, 9 weeks, 12 weeks, 15 weeks after distraction.
The results obtained in this study showed that bone strength, bone mineral density of both cancellous and cortical bones, periosteal circumference increased with time during callotasis. As for biophysic changes, T1 relaxation time mesured by phosphorus-31 solid-state nuclear magnetic resonance (NMR) increased after 21 days of distraction, which means an increase in bone strength. In addition, mineral to matrix ratio measured by Fourier transform infrared spectroscopy (FTIR) increased during distraction, which suggests that mineral to matrix ratio may be one of important indices of strength and maturation of bone in distraction osteogeneis.
Based on these facts, T1 relaxation time by phosphrus-31 solid state NMR and mineral to matrix ratio by FTIR become promising predictors of maturation and strength of bone during distraction osteogenesis.
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