Aetiology and cause
Osteoarthritis is the most widespread of all chronic joint diseases, making up half of all arthritic forms and being one of the most common reasons for analgesic treatment. The acute pain of early osteoarthritis often tends to fade within a year of its appearance, but may return and become chronic if the affected joint is overburdened.
Primary arthritis has multifactorial aetiologies whereas secondary arthritis is generally due to e.g. trauma, infection, faulty posture, neurological disorder or crystal deposition.
Arthritis should not be considered as a degenerative disorder. It is a local inflammatory cartilage disorder with involvement of some cytokine (e.g. IL-1), that leads to destruction and loss of joint cartilage and subchondral bone.1
An increasing imbalance between anabolic and catabolic processes in the joint cartilage causes progressive destruction of the cartilage accompanied by plastic alterations of the joint-adjacent bone and reactive changes of the joint capsule.
1 Burnett BP et al. Metabolic mechanisms in the pathogenesis of osteoarthritis. A review. J Knee Surg. 2006; 19:191-197.