Knee and hip pain caused by arthritis limits the body from completing normal activities. One way to help reduce pain and improve long-term function might be with knee and hip replacements, explained Dr. Russ Guin, a sports medicine physician at University Medical Center and assistant professor at UA’s College of Community Health Sciences.
“Indications for knee replacement include intolerable pain, limitations of everyday activities and osteoarthritis, which happens when the cartilage breaks down and worsens over time,” Guin said during a September Mini Medical School presentation to UA’s OLLI Program.
Mini Medical School is a series of lectures provided to the OLLI program by CCHS faculty. The College also operates University Medical Center.
For a total knee replacement, damaged cartilage and bone from the whole knee is removed and replaced with metal and plastic prosthetic implants. For a partial knee replacement, only the parts of the knee affected with arthritis are replaced with prosthetic implants.
“Eighty to 85% of patients are satisfied with their knee replacement due to reduced pain, improved function and enhanced quality of life,” Guin. “The 15% to 20% that are dissatisfied is due to issues with expectations, continued pain and poor function. There is a 35% chance for men and a 20% chance for women needing revisions over time.”
Revisions are required when the prosthetic implants fail, when there are signs of possible infection (the most common reason for revisions), pain, instability and implants loosening, Guin said.
Osteoarthritis is often what leads to the need for a hip replacement. “Almost 90% of patients needing hip replacements is because of osteoarthritis – because of the breakdown of the damaged cartilage,” Guin said. “Indications are intolerable pain, stiffness in the hip joints and limitations of activities.”
During a total hip replacement, damaged cartilage in both the ball and socket of the hip are replaced with metal implants. For a partial hip replacement, only the ball part of the hip joint is replaced.
Physical therapy is typically required after knee and hip replacements because it improves strength and movement and helps people return to their everyday activities, Guin said.