An estimated 7 million people in the United States – or 2 out of every 100 – have had a total knee or hip replacement, according to a Mayo Clinic study. The research was the first major study to estimate how common joint replacement has become in the United States.
Dr. Daniel J. Berry, chairman of orthopedic surgery at the Mayo Clinic and author of the study, reviewed federal databases on surgeries and life expectancy trends and reported those findings this month at the American Academy of Orthopaedic Surgeons conference in New Orleans.
Until now, since the United States didn’t have an established joint replacement registry, there was no good way to estimate how many people are currently living with artificial joints. This information can help researchers answer questions about cost, how long joint replacements last, and how best to replace them over time.
The information is even more valuable considering the number of knee and hip replacements is expected to skyrocket in the next several years as Baby Boomers age. And, for the most part, joint replacements are considered a success.
There are exceptions, however. Traditional hip replacements are made with plastic or ceramic parts and can last 20 years or more before needing to be replaced. In the past decade, manufacturers began introducing all metal hip implants designed to hold up better over time. However, these implants were prone to corroding inside the body, leading to premature failures. With no joint registry established in the United States, it was hard to see just how big the problem was.
As reports of complications with metal-on-metal hip implants began mounting both in the United States and around the world, recalls were issued by companies such as Stryker Corp., Biomet, and Johnson & Johnson. Medical experts worldwide also warned surgeons that the devices should no longer be used and patients currently using them should be monitored on a regular basis for signs of device failure such as metal ions in their blood.
Thousands of lawsuits have been filed against the manufacturers of these defective devices. Last month, Biomet agreed to pay $200,000 each to hundreds of people injured by its hip implant. Last fall, Johnson & Johnson agreed to pay $2.5 billion to settle about 8,000 metal hip implant lawsuits.