In the race to create longer-lasting and less-painful artificial joints, University of Alabama at Birmingham researchers are exploring whether nanodiamond coatings can reduce wear on joints made of metal alloys. The work is important because, according to the American Academy of Orthopedic Surgeons, more than 418,000 knee replacements and 328,000 hip replacements are performed in the United States each year; the numbers are expected to balloon as the nation’s population ages.
Joint wear generates debris that can cause pain, limit mobility and hasten joint failure. Debris particles from metal surfaces are absorbed by scavenging immune cells called macrophages, which then secrete chemicals that cause swelling and pain. This inflammation turns on bone-eating cells near implants, and bone-loss increases the likelihood implants will break loose and require a second surgery.