The relationship between hyaline cartilage and subchondral bone lesions in the patients with knee osteoarthritis

Methods: The proximal tibial was resected as a single osteochondral unit during total knee replacement surgery. The X-ray films before and after surgeries were analysed. Cartilage degenerative regions were assessed using the modified 3-graded Outerbridge classification. Grade A: normal; Grade B: (i) softening and swelling of the cartilage, or (ii) fragmentation and fissuring of an area that does not reach the subchondral bone. Grade C: erosion of cartilage down to bone. Ten osteoarthritic osteochondral units and three normal osteochondral units from the Bone Bank (NOCERAL) were scanned with HR-pQCT. The density of bone volumes of the subchondral bone plates and the trabecular subchondral bones were measured. Scanning Electron Microscope (SEM) was used to observe and measure the microstructure of cartilage interface.