U.K. health officials are warning that individuals who received combination DePuy MITCH and Stryker Accolade metal-on-metal hip replacement components are experiencing a particularly high failure rate.
The U.K.’s Medicines and Healthcare products Regulatory Agency (MHRA) issued a medical device alert (pdf) on April 2, indicating that there is an increased rate of revision surgery among individuals who had a DePuy MITCH acetabular cup/modular head used in combination with uncemented Stryker Accolade femoral stems.
The MHRA is advising orthopedic surgeons not to use the components together and to follow up on all patients implanted with the combination of DePuy and Stryker components as part of a metal-on-metal total hip replacement.
The warning came following an analysis of data from the England and Wales National Joint Registry (NJR), which discovered a cumulative revision rate of 8.8% for MITCH TRH hip resurfacing systems. That is higher than what the U.K.’s National Institute for Health and Clinical Excellence (NICE) considers acceptable, and when the DePuy MITCH hip is combined with the Accolade femoral stems, the failure rate jumps to 10.7%.
MHRA also indicated that patients who received the implant combination should be tested annually for signs of high blood metal ions from the hip replacement, which could indicate that they are suffering from metallosis, a form of metal blood poisoning.
Individuals who have a blood metal ion level of greater than 7 parts per billion they should get a second blood test three months later. That level of blood metal ions indicates the potential for soft tissue damage, especially if that number appears to be rising.
In cases where high levels of metal ions are detected, MHRA recommended that the patient undergo an ultrasound or magnetic resonance imaging to look for potential damage.
The MITCH TRH components were manufactured by Finsbury Orthopaedics and distributed by Stryker in the U.K. from May 2006 through October 2011. Finsbury was acquired by DePuy Orthopaedics in 2009, which is a subsidiary of Johnson & Johnson.
The warning is the latest blow to metal-on-metal hip resurfacing and replacement systems, which have been the target for an increasing number of calls for an industry-wide metal-on-metal hip recall.
In August 2010, a recall for the DePuy ASR metal-on-metal hip system was issued after it was discovered that about one out of every 8 of the hip implants were failing within five years of surgery. More than 3,500 people throughout the United States are now pursuing a DePuy ASR hip lawsuit after experiencing problems with the implant.
In May 2011, the FDA asked device manufacturers to obtain more information about the level at which the metal particles shed by hip replacements becomes dangerous, how much metal they actually shed and what the potential side effects of metallosis are.
Last week, the FDA announced that an independent panel of experts will be convened this summer to review the safety concerns with metal-on-metal hip replacement and resurfacing systems, and make recommendations about any regulatory actions that should be taken to protect consumers from the risks associated with the microscopic shavings of cobalt and chromium that may be released into the body.