The most common cause of knee disability is osteoarthritis, the breakdown of cartilage that triggers severe knee pain and stiffness.

When pain medications and other treatments are no longer effective, you may need a total knee replacement.

Knee replacement surgery was first performed in 1968. Since then, improvements in surgical materials and techniques have greatly increased its effectiveness. According to the American Academy of Orthopedic Surgeons, more than 600,000 total knee replacement surgeries are performed on adults in the United States each year.

During the procedure, your surgeon will first remove damaged cartilage and bone. He will then reshape the surfaces to fit a prosthetic joint.

The prosthetic joint is made of three synthetic components— a metal femoral shell, a metal and plastic tibial component and a plastic patellar component— which are cemented into place in the knee.

Before closing your incision, your surgeon will bend and rotate your knee, to ensure it functions properly.

After surgery, over 90 percent of patients experience dramatic pain relief and improved knee function. The new joint will last 10 to 20 years.