An Assessment of the Mechanical Properties of Long Bone Fractures Using an Impulse Response Method

Ahn, Myun Hwan; Jang, Woo Seok; Kim, Dong Han

Abstract

PURPOSE
To establish the basis for a non-invasive and non-destructive assessment of the mechanical properties during natural fracture healing by analyzing the vibrational property of the fracture healing and comparing the vibrational property, the bone healing status (as determined by X-ray) and the mechanical strength parameters.
MATERIALS AND METHODS
The tibial shafts of rabbits were broken under general anesthesia. The rabbits were sacrificed at 2, 4, 6 weeks after the fracture, then X-rays of the fractured tibias were sequentially taken to detect the fracture healing. The vibration mode and the biomechanical strength were measured.
RESULTS
According to the results of a multiple regression analysis, the standardized coefficients of callus, apposition, lateral angulation, DAMP1, FREQ1 in the fractured tibias, were -0.80, -0.23, -0.21, -0.25, -0.25. In normal contralateral tibias, the standardized coefficients of the area, FREQ1, DAMP1, FREQ2, DAMP3 were -0.73, 0.28, 0.41, 0.39, -0.25.
CONCLUSION
A monitoring of the fracture healing process that utilizes the frequency response function is thought to be useful in detecting the early phase of healing within 4 weeks. Additional studies on the vibrational characteristics of the healing bones after a clinical union or after simillar pathologies should be pursued so that future diagnostic applications ca be made.