Knee arthritis develops when a part, or all, of the cartilage covering the knee joint wears away.  Typically this occurs in older people as years of activity, hard work or sporting injuries begin to take their toll.  Occasionally arthritis develops in younger people as a result of injury, genetic susceptibility or just bad luck.

Once arthritis is established the main surgical options include:

• osteotomies – to realign the joint
• partial knee replacement – replacing the worn section and leaving the "good bits" alone
• total knee replacement