The purpose of this study is to investigate differences of chemical composition between subchondral bone in advanced osteoarthritic (OA) and non-OA distal femur.

Twenty femurs were harvested, respectively. The subchondral trabeculae were obtained from the middle of medial articular surface of distal femurs. A 10 mm diameter cylindrical saw was used to harvest. Raman spectroscopy, a non-destructive technique, was employed to determine the chemical information of the trabecular bones in the human distal femurs.

The maximum intensity of the phosphate peak was 2,376.51±954.6 for the non-OA group and 1,936.3±831.75 for the OA group. The maximum intensity of the phosphate peak observed between the two groups was significantly different ( P =0.017). The maximum intensity of the amide I peak were 474.17±253.42 for the nonOA group and 261.91±205.61 for the OA group. The maximum intensity of the amide I peak were significantly different between the two groups ( P =0.042). Also, among other chemical and matrix components (Hydroxyproline,Carbonate, Amide IIIdisordered;ordered, and CH2), the spectrums showed similar significant differences in the intensity ( P =0.027, P =0.014, P =0.012; P =0.038, P =0.029). Area integration were performed to determine disorder in collagen's secondary structure via amide III (alpha helix/random coil). The value of the alpha helix to random coil band area are significantly different ( P =0.021) and result showing that there was a trend toward higher collagen maturity for the nonosteoarthritic bone specimens.

The result suggested that OA may affect the chemical compositions of trabecular bone, and such distinctive chemical information may be.