In August 2010, DePuy Orthopaedics issued a voluntary recall of its ASR Hip System, a metal-on-metal hip implant system, because a higher number of patients than previously reportedsuffered from pain, swelling, and difficulties walking. This system was first available in July 2003and was marketed in the United States starting in 2005. The ASR Hip System was used in an estimated 93,000 patients, of which about 30,000 are in the United States. The New York Times reported that recall by DePuy Orthopaedics unit of Johnson & Johnson was yet another recall of a popular Johnson & Johnson product, joining recalls of liquid children’s Tylenol in the United States and Acuvue contact lenses in Japan, Asia, and Europe.
The hip joint is a ball-and-joint socket (the thigh bone or femur has a femoral head (ball) at the top, which fits into the concave surface (joint) of the pelvis). There are four types of hip replacement options in the United States:
Depending on the level of deterioration, there are two options for hip implant systems: total hip replacement and hip resurfacing. The DePuy ASR XL total hip replacement is a metal ball that replaces the femoral head and fits into the one-piece metal component placed in the pelvis. The DePuy Hip Resurfacing System is composed of a metal cap, which is placed over the femoral head and a metal cup lining the concave surface of the pelvis.
In April 2010, the United Kingdom’s Medicines and Healthcare products Regulatory Agency (MHRA) released a medical device alert as a result of information from the England and Wales National Joint Registry, which was superseded by a medical device alert issued in June 2012. The recall was issued because a higher number of ASR patients than previously reported to DePuy required a revision surgery, which is a second surgery where the hip implant is removed and replaced. This data showed that 12% of patients who had an ASR resurfacing device and13% of patients who had an ASR total hip replacement device required revision surgery within five years of receiving an ASR implant. The percentage of revision surgeries is about twice the industry average and in contrast to the usual fifteen years that many artificial hips last. The FDA acknowledges that there are differences between the regulatory systems in the United States and the United Kingdom, so some of the United Kingdom’s data may not directly relate to the United States, which means that the frequency of negative reactions in the United States is unknown.
Metal-on-metal hip systems have some unique complications including the possibility that small metal particles can wear off of the device as a result of the metal ball and cup sliding against each other during movement. These tiny metal particles may enter the space surrounding the implant or enter the bloodstream, which can cause damage to the surrounding bone and tissue and require revision surgery. There is currently no test to determine if a patient will or will not have a reaction to a metal-on-metal hip system (ARMD – adverse reaction to metal debris). The MHRA suggests that early revision surgery may allow for a better revision outcome, especially given the risk that some people may develop progressive soft tissue damage which could affect the results of a revision. Other symptoms and complications of metal-on-metal hip systems include pain, swelling, and difficulty walking, which could be caused by the implant loosening, the bone around the implant fracturing, or the two parts of the implant becoming misaligned.
Patients with an ASR Hip System affected by the recall should be evaluated by their doctor to determine if additional surgery is required as a result of the recall. If you have a hip replacement that may be affected by the recall and suffer from the symptoms discussed above, your doctor will perform blood tests (blood metal ion testing to test for cobalt or chromium ions in the bloodstream), MRI to check for soft tissue problems, and x-rays to evaluate whether your implant is aligned properly and if there is any damage to the surrounding bone. Then, if you require arevision surgery, your doctor will help you determine an appropriate replacement system. Not everyone with a DePuy ASR hip implant require a revision. In some cases, where there is no misalignment and/or the patient is asymptomatic, doctors may choose to continue monitoring to ensure that the patient does not develop problems in the future rather than replace a well-functioning hip implant. Still, it is important to have your doctor evaluate you for potential problems.
DePuy: Hip Recall Surgeon Information
FDA: Medical Devices: Metal-on-Metal Hip Implants
FDA: Concerns about Metal-on-Metal Hip Implant Systems
FDA: Medical Devices Recalls Specific to Metal-on-Metal Hip Implant Systems
MHRA: Medical Device Alert (04-22-10)
MHRA: Medical Device Alert (06-25-12)
AAOS: Questions and Answers About Metal-on-Metal Hip Implants
NYTImes: Johnson & Johnson Recalls Hip Implants
NYTimes: Hip Maker Discussed Failures
NYTimes: Hip Device Phaseout Followed F.D.A. Data request
Arthritis Today: Two Hip Replacement Implants Recalled