Osteoarthritis is a degenerative disease where the articular (joint) surfaces become damaged over time.  The normal joint cartilage becomes worn, narrowing the space between the two bones and causing pain as the joint moves.  Small cysts and osteophytes (extra spurs of bone) may form on the joint surfaces, which also limits normal joint movement.

Osteoarthritis may be linked to a previous injury, including fractures through the joint or damage to the surrounding ligaments.  It is also thought to have a hereditary component.

Symptoms include:

• Joint pain and stiffness
• Reduced range of movement
• Localised swelling
• Joint deformity (normally seen in later stages)