20. Osteoarthritis

Osteoarthritis is characterised by loss of hyaline cartilage in a part of a synovial joint, together with changes in the (subchondral) bone directly beneath the cartilage and an inflammatory reaction of the synovial membrane of that joint. Osteoarthritis is further characterised by joint pain after loading, stiffness of the joint and restriction of movements. If the cause of osteoarthritis is not clear, one speaks of primary or idiopathic osteoarthritis. The condition can also occur after a distinct cause (infection or trauma) and then we speak of secondary osteoarthritis.