Maker of Metal Hip Implant Aware of Problems

Court documents submitted in litigation in a California Superior Court in Los Angeles noted that Johnson & Johnson was aware of an abnormally higher failure rate for its Articular Surface Replacement (ASR) all-metal hip implant for as long as two years prior to the device’s recall, according to a New York Times review.The trial is the first of over 10,000 lawsuits filed in relation to the ASR. The internal Johnson & Johnson report is one among the many hundreds of documents expected to shed light on the failure of the hip implant in the California trial.

Hip implants, which are generally made from metal and plastic, often last for up to 15 years before they wear out and need to be replaced. Although the hip implants can fail prematurely for a variety of reasons, the early replacement rate is typically 1 percent after a year, or 5 percent at five years.

An internal investigation revealed that the company estimated that the medical device would fail within a span of five years for 40 percent of patients who received it. Before the 2010 recall, the company was publicly minimizing the impact of equally disturbing findings from a British implant registry. The manufacturer, the company’s DePuy Orthopaedics unit, challenged the findings of the National Joint Registry of England and Wales, arguing that sample sizes in the British registry were too small to make a generalized statement about the medical device. The company sold the ASR to 37,000 people in the U.S. and 93,000 patients world-wide.

The ASR belonged to a once-popular class of hip implants in which the cup and ball component were both made of metal. In metal-on-metal hip implants, the metal ball and the metal cup can slide against each other during walking or running, wearing away tiny metal particles. Metal can also be released from other parts of the implant where two implant components connect. The release of metal  around the implant may cause damage to bone and/or soft tissue surrounding the implant and joint. This is sometimes referred to as an “adverse local tissue reaction (ALTR)” or an “adverse reaction to metal debris (ARMD).”

The devices have come under the focus of the FDA, which issued a safety communication in mid-January with updated information and recommendations to patients and health care providers.