Arthritis destroys the cartilage covering the ends of bones. The normally smooth joint surfaces become rough and uneven. As a result, the joint cannot move smoothly. It becomes stiff, and swollen, causing pain and limited movement

Arthritis of the Knee joint may be caused by:

• age-related osteoarthritis (wear -and-tear arthritis)
• chronic inflammatory disease ( rheumatoid arthritis)
• traumatic arthritis , which can occur after a fracture or other bone injury
• some birth defects and growth disorders

Reasons for Knee Replacement ( Arthroplasty)

Your general practitioner and orthopaedic surgeon may recommend knee replacement surgery in the following cases:

• chronic pain that has not been relieve by anti-inflammatory medications, physical therapy, and the use of a cane or other devices
• pain is so severe that it restricts work, walking, recreation, and daily activities
• sleep is disturbed due to night pain
• the knee is very stiff and may be swollen
• X-Ray examination confirms advanced arthritis
• avascular necrosis ( a lack of blood supply to the ends of the bones) has damaged the joint; it is usually caused by trauma