How likely are premature failures of the DePuy ASR XL Acetabular Hip Replacement System? When DePuy Orthopedics issued recalls for the ASR XL Acetabular Hip Replacement System and the ASR Hip Resurfacing System last August, the company said data from the National Joint Registry of England and Wales indicated that 1 out of every 8 patients (12%-13%) had to undergo revision surgery within five years of receiving the defective devices. But according to a Bloomberg report, doctors in the United Kingdom (U.K.) say they’re seeing early failures of the ASR XL Acetabular Hip Replacement System at a rate closer to 50 percent.

A statement issued this week by the British Orthopaedic Association and the British Hip Society said data from four surgeons shows the rate of revision surgeries in patients who received the DePuy ASR XL Acetabular Hip Replacement System ranges from 21 percent after four years to 49 percent after six years. The statement went on to say that the 21 percent revision rate at 4 years could rise to 35 percent “if all currently known painful implants progress to revision,” Bloomberg said.

The orthopedists didn’t report on the resurfacing system in the statement, which was not sold in the U.S., according to Bloomberg. The statement also limits its commentary to large diameter implants, without defining “large diameter.” Bloomberg noted that DePuy’s original recall notice said that revision rates would probably be highest for ASR head sizes less than 50 millimeters in diameter, which are normally used in female patients.

The ASR Hip Implant System is a metal-on-metal hip implant made of chromium and cobalt, consisting of a cup that’s implanted into the hip with a ball joint that connects to the leg. It is believed that many of the complications linked to the DePuy ASR XL Acetabular hip implant are caused by wearing of the metal components, which can allow metal shavings to make their way into patients’ bloodstreams, leading to tissue breakdown, bone loss, and even the formation of non-cancerous tumors. The shedding of metal shavings can cause cobalt poisoning, a disorder that, if left untreated, can put patients at risk of tinnitus (ringing in the ears), vertigo, deafness, blindness, optic nerve atrophy, convulsions, headaches, peripheral neuropathy, cardiomyopathy, and hypothyroidism.

Since the DePuy ASR hip implant recall was issued in August, the device maker has been named in scores of product liability lawsuits. Late last year, all federal DePuy hip implants lawsuits were consolidated in a multidistrict litigation before Judge David A. Katz in the U.S. District Court for the Northern District of Ohio.

According to Bloomberg, more than 350 lawsuits have been consolidated in the MDL, more than 220 more are pending in California state court, and another group of cases is pending in New Jersey state court.