Definition:
Osteoarthritis (OA) is an inflammatory joint disorder characterised by degradation of both proteoglycans within the cartilage and sub-chondral bone in the joint. Continued breakdown of proteoglycans and loss of glycosaminoglycans leads to abrasion of the articular cartilage and functional deterioration of the joint. This deformity and ongoing turnover of the cartilage matrix leads to pain, stiffness and joint swelling.
OA is the most common form of arthritis and frequently affects hands, knees, hips, and spine. As many as 90% of individuals over the age of 40 show degenerative changes on x-ray; however not all of these individuals have symptoms. OA can be localised to one or two joints or generalised to three or more joints.

Risk factors:
Major causative factors and risk factors that can contribute to the incidence of OA include:
• Poor diet
• Sedentary lifestyle
• Obesity
• Bowel Toxicity
• Hypothyroidism
• Insulin resistance.
• Increasing age
• Genetic predisposition
• History of inflammatory disease
• Congenital bone and joint disorders
• Crystalline deposition in joints
• Trauma to or near the joint (acute or chronic)
• Mechanical factors (e.g.: unequal lower limb lengths)
• Repetitive stressful joint use
• Wilson's disease
• Hypo-parathyroidism
• Haemochromatosis

Signs and Symptoms:
Common signs and symptoms of OA include the following:
• Localised joint pain (often described as a deep ache), worsened by movement and improved with rest
• Morning stiffness or stiffness after inactivity for more than 15 minutes
• Soft tissue swelling
• Warmth on palpation
• Bony crepitus
• Synovial fluid
• Limited range of motion
• Muscle atrophy
• Subluxation
• Bony hypertrophy causing gross deformities