Abstract
Purpose
The purpose of this study is to analysis and compare the micro-structural and mechanical properties of subchondral trabecular bone of non-osteoarthritic and osteoarthritic distal femur using a micro-images based on finite element analysis.
Materials and Methods
Fifteen distal femur were harvested from the eight cadevers(5 males, 3 females; non-OA, 10, OA, 5). The subchondral trabeculae were obtained from the middle of artticular surface of distal femurs(Fig. 1). Cylinderical saw with 10 mm diameter was used to acquire trabecular bone core. Total 15 specimens were scanned using micro-CT (SkyScan-1172, SKYSCAN, Belgium) at 24.9ãŽ> of spatial resolution under 70ãŽ,'s voltage and current of 141ãŽ,. 2-D images with were established by an imaging software (TomoNT, SKYSCAN, Belgium) as shown in Fig. 2. Histomorphologic index, trabeculae thickness (Tb.Th), trabecular separation (Tb.Sp), bone volume (BV), bone volume fraction (BV/TV), structure model index(SMI) were determined by the ANT software (Table 1). Based on 2-D images, a finite element model was reconstructed (Fig. 3). Finite element analysis was done using BIONIX (CANTIBIO, Suwon, Korea). Yield stress (MPa), Stiffness was calculated with ANSYS 10.0(ANSYS, Inc) (Fig. 4).
Results
The descriptive statistics of the microstructural and mechanical parameters are presented in Fig. 4. The results showed that trabecular bone of osteoarthritic distal femur had a decrease in Tb.Th, BV/TV and had an increase in Tb.Sp and SMI than non-osteoarthritic group. There was a decrease in the yield stress.
Conclusion
The results of bone morphometry index and strength showed that subchondral trabeculae of osteoarthritic group was more degenerative structure and decreased strength. And, this results are contribution to understand the osteoarthritic change in bone remodeling aspect.
