Knee replacement surgery replaces parts of injured or worn-out knee joints. This also is known as knee arthroplasty. During the surgery, damaged bone and cartilage are replaced with parts made of metal and plastic.

Knee replacement surgery can help ease pain and make the knee work better. To decide whether a knee replacement is right for you, a surgeon checks your knee's range of motion, stability and strength. X-rays help show the extent of damage.

Hip replacement

During hip replacement, a surgeon removes the damaged sections of the hip joint and replaces them with parts usually constructed of metal, ceramic and very hard plastic. This artificial joint (prosthesis) helps reduce pain and improve function.

Also called total hip arthroplasty, hip replacement surgery might be an option if hip pain interferes with daily activities and nonsurgical treatments haven't helped or are no longer effective. Arthritis damage is the most common reason to need hip replacement.