Quantitative Parameters for the Degeneration in Cartilage and Subchondral Bone of Human Knee by 3-D Ultrasound Scanning System.

This study was aimed at investigating the use of ultrasound parameters obtained non-invasively through soft tissue (ST) to evaluate degeneration in cartilage and subchondral bone (SB) in the human knee. We developed a 3-D ultrasound system and introduced the ratio parameters Rcb and RcbT to suppress the attenuation effect in the ST or in both the ST and cartilage. As reference measurements, the grade for cartilage by visual judgment (Gsum) and ultrasound parameters for the cartilage and the SB were directly evaluated under arthroscopy. Rcb correlated significantly with Gsum (rs = -0.63) and with the corresponding parameter obtained directly under arthroscopy (r = 0.55). RcbT also correlated significantly with Gsum (rs = -0.46) but was not superior to Rcb. Rcb is considered to be an efficient parameter that reflects the total degeneration in both the cartilage and SB, including the information on cartilage thickness.