Acoustic impedance changes in cartilage and subchondral bone due to primary arthrosis

The mean impedance value in subchondral bone was 6.28 ± 0.54 Mrayl. A significant increase of the acoustic impedance within the first 150 μm relative to cartilage-bone interface was observed in 65.5% of the investigated sections. We hypothesize that the impedance increase close to the bone cartilage boundary is an indicator for subchondral sclerosis.