Aso K, et al. - In view of the considered contribution of subchondral bone and osteochondral junction to osteoarthritis (OA) knee pain, researchers investigated osteochondral pathologies specifically associated with symptomatic human knee OA. They determined macroscopic chondropathy scores for two matched groups of medial tibial plateau (n=31 per group). Total knee replacement was done on one group for OA knee pain (symptomatic chondropathy) while the other had not sought help for knee pain and died from unrelated illness (asymptomatic chondropathy). Findings revealed an association of subchondral pathology with symptomatic knee OA. This association was observed independently of chondropathy and synovitis. Bone pain in knee OA correlated with features like increased NGF expression in osteochondral channels and osteoclast density