If you have received a metal-on-metal hip replacement, you might be wise to have a blood test to make sure it’s not wearing down too quickly. The test, called metal ion testing or trace metal analysis, measures levels of cobalt and chromium in your blood or blood components.
These trace metals at extremely low levels are important to good health. But people who have undergone total joint replacement often have slightly higher levels as the wearing of the components produces many small particles of metal alloys, says Joshua Jacobs, MD, professor and chairman of orthopedic surgery at Rush University Medical Center in Chicago. Levels higher than 7 parts per billion could indicate that components are wearing abnormally.
If your new hip is one of the ASR implants that DePuy recalled, DePuy will cover the cost of your test and follow-ups.
Although the test can provide useful information, it is only one step in identifying problems with joint replacements, says Dr. Jacobs. “If a patient has a well functioning metal-on-metal hip with no pain, and [X-rays] and physical exams are normal, I don’t think there is a necessity to get an ion level.”
What Hips Were Recalled?
Dupuy Orothopaedics, a division of Johnson & Johnson, has recalled two types of ASR hip implants in use since July 2003 due to early failure rates. About 12 percent need revision surgery within five years – roughly twice the industry average, says Kevin J. Bozic, MD, an orthopaedic surgeon and vice chairman of orthopaedics at the University of California at San Francisco Medical Center.
If you’re having trouble with an ASR implant, DePuy will help cover the costs of monitoring and replacement. For more information, call DePuy’s helpline at (888) 627-2677.