The real record is in how many more people are having joint replacements each year compared to the previous year. In the past 10 years the number of total hip replacements has doubled. The number of total knee replacements has tripled.
People who study statistics and report trends agree this is a fast growing upward trend. The increase in obesity and osteoarthritis seem to be behind the big push. New implants
and improved technology have also been a factor in the increased numbers.
Researchers expect to see this growth continue at least for a while. Not only that but as more and more people have their first joint replacement, the number of revisions will go up, too. Either problems will develop and the implant will have to be repaired or replaced--or younger adults getting implants will wear them out and need new ones.