New medical data from the U.K. indicate that DePuy hip implants fail at a rate four times greater than the manufacturer said when it recalled the devices last August, according to the British Orthopaedic Assocation and the British Hip Society.
When DePuy Orthopaedics, a part of Johnson and Johnson’s Medical Devices & Diagnostics group, recalled its ASR XL Acetabular System, it cited data from the National Joint Registry of England and Wales saying 13 percent of ASR XL devices implanted in patients failed within 5 years. Now, more reliable data collected from four surgeons indicates the failure rate for the ASR XL Acetabular system is 21 percent after just four years and 49 percent after six years.
“It’s probably the best indicator so far of what the failure rate is likely to be,” John Skinner, an orthopedic surgeon, told Bloomberg. “As far as I can tell, it’s reliable.”
Patients whose DePuy hip implants have failed must undergo a revision surgery to fix the implants or replace them altogether with another brand. In some patients, the extent of damage caused by the implants to supportive bone and tissue has been so severe, multiple revision surgeries are needed.
According to U.K. medical databases, about 10,000 of the recalled DePuy articifical hips were implanted in patients. About half of those patients received the ASR hip resurfacing system while the other half received the total-hip implants known as the ASR XL Acetabular system.
Skinner said that about 10,000 of the hips were implanted in the U.K., including 5,000 or so resurfacing devices and 5,000 of the ASR XL prostheses, also known as total-hip replacements. Only the ASR XL system gained FDA approval in the U.S., where about 37,000 patients received the faulty devices.
Both DePuy hip implant systems contain metal-on-metal parts that often degrade and loosen prematurely. The moving parts frequently release heavy metal toxins into the bloodstream and can turn the bone and issue surrounding the implant into a black, tar-like decay. Patients who have been harmed by the hip implants usually report constant pain, diminished ability to walk or inability to walk, and a number of symptoms associated with metal poisoning.