1996 Fiscal Year Final Research Report Summary
MECHANICAL EVALUATION OF FRACTURE HEALING USING THE IMPULSE RESPONSE METHOD IN A FRACTURE MODEL OF DOG
| Project/Area Number |
07671578
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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 | SHINSHU UNIVERSITY |
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Principal Investigator |
NAKATSUCHI Yukio SHINSHU UNIVERSITY,SCHOOL OF MEDICINE,ASSOCIATE PROFESSOR, 医学部, 助教授 (80115360)
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| Co-Investigator(Kenkyū-buntansha) |
NOMURA Akio SHINSHU UNIVERSITY,FACULTY OF ENGINEERING,DEPARTMENT OF INFORMATION ENGINEERING,, 工学部・情報工学科, 教授 (00115362)
SAITOH Satoru SHINSHU UNIVERSITY,SCHOOL OF MEDICINE,SHINSHU UNIVERSITY HOSPITAL,LECTURER, 医学部・附属病院, 講師 (20175350)
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| Project Period (FY) |
1995 – 1996
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| Keywords | fracture healing / fracture of dog / tibia / impulse response method / mechanical strength |
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| Research Abstract |
The strength of the fracture healing in a long bone can be mechanically evaluated with the resonant frequency which is measured by the impulse response method (IRM). Tenadult beagle doge were used to make fracture models in their tibias. The tibia was opened in its mid-shaft under an intravenous anesthesia, transversely incised by a bone saw and fixated with a SMO plate and four screws with a gap from zero to 2mm. There were two primary vibrational modes in the dog tibia, on its asgital and frontal planes. The resonant frequency on the frontal plane was used for monitoring the fracture healing process and the normal value of resonant frequency of the sound tibia ranged from 800 to 1100 Hz. The resonant frequency, x-ray examination, DXA,hematology and biochemical examination of the blood were routinely performed once a week until 8 (5 dogs) or 18 (5 dogs) weeks postopertively when the dogs were sacrificed.
The change of resonant frequency was compared with the roentgenogram in the fracture healing process. The resonant frequency did not reach the value of sound side at 8 weeks postoperatively but did at 18 weeks in all dogs. The grester the gap was, the more the decrease of postoperative resonant frequency was. The resonant frequency at the first week after operation was the lowest in all dogs. An acute increase of the frequency was found one two weeks prior to that the gap was filled up with callus. Blood calcium increased at one week postoperatively and returned to normal value at 3 weeks. Blood alkaline phosphatase showed a peak at the first week and then declined. Bone mineral density of the fracture segment revealed an acute increase until 8 weeks postoperatively. Histological fracture healing was incomplete at 8 weeks but was complete at 18 weeks postoperativery. That histological findings was coincident with the change of resonant frequency.
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