Smith & Nephew is a London-based medical device manufacturer that manufactures several lines of joint replacement systems for hips, knees and shoulders. The company is the fourth largest manufacturer of hip implants in the United States, with a 12.1 percent market share and $313 million sales in 2010. It has also had its share of defective devices and hip implant recalls, however. In the United Sates, many recalls of defective joint implants are voluntary and initiated by the manufacturers. This usually happens when too many adverse events occur as a result of the device. The U.S. Food and Drug Administration (FDA) will step in if the manufacturer refuses to voluntarily recall a defective product. In 2012, Smith & Nephew issued a voluntary recall for the metal liner in one of its hip implant devices, the R3 Acetabular System.
The R3 Acetabular System was released in Europe and Australia in 2007, and in 2009 the hip replacement system was launched in the United States. Smith & Nephew initiated a worldwide recall of the metal liner in its R3 Acetabular System on June 1, 2012, after reports of loosening, pain, device failure, infection, metal sensitivity and dislocation. About 7,700 R3 devices have been implanted worldwide since 2009. The device experienced a higher than normal revision rate — 6.3 percent in four years compared with the average of 2.89 percent for primary total hip replacements. In the recall, Smith & Nephew stated that the metal liner was not “performing as well” as the company expected and that it was “not satisfied with the clinical results.”
However, the company still claims that the modular R3 Acetabular System is designed to enhance stability and give surgeons more options. The R3 system remains on the market and now includes a cup made of plastic, metal or ceramic; a femoral head made of the company’s proprietary OXINIUM Oxidized Zirconium, cobalt chrome or Biolox ceramic; and a liner made of OXINIUM or cross-linked polyethylene (XLPE) plastic. When used with the metal liner, the R3 Acetabular System can become a metal-on-metal (MoM) implant. Like other companies that manufacture these types of implants, Smith & Nephew marketed the metal liner option of the R3 Acetabular System as durable and wear-resistant. However, instead of long-lasting durability, an alarming number of these implants have failed prematurely.
Complications and Problems with the R3 Acetabular SystemComplications and problems relating to the metal liner of the R3 Acetabular System may be the result of its MoM design. The metal liner is made of cobalt and chromium. Cobalt-chromium implants have been shown to release ions into the body, and studies have revealed that chromium and cobalt ions are carcinogens linked to blood poisoning and genotoxicity (DNA damage). The ions can cause local tissue reactions that destroy muscle and bone and spread to other organs. Cobalt has also been linked to cardiomyopathy, or heart muscle disease. The deterioration of bone and muscle around the implant can lead to loosening and device failure. All of these complications have been known to lead to metallosis, which is also known as metal poisoning.
Studies by Australia’s National Joint Replacement Registry and the United Kingdom’s National Joint Registry did not find evidence of metallosis–metal poisoning–occurring in patients who were implanted with the metal liner of the R3 Acetabular System. However, patients did experience metal sensitivity and other complications that can lead to metallosis. It is important to note that MoM hip implants manufactured by other companies have presented metallosis as a complication, and this may be a future concern for R3 Acetabular System recipients.
After the recall, the company sent out “hazard alert” letters to doctors who had implanted the metal liners, claiming that the recall was a “precautionary step.” Smith & Nephew also said it was unable to identify one single reason for the device failure, but there were reports of “infection, dislocation, metal sensitivity, loosening/lysis and fracture.”The letter further instructed doctors to follow up with their patients if they had received the liner.
While there have been no recalls for the OXINIUM ceramicliner of the R3 Acetabular System, the U. S. Food and Drug Administration (FDA) issued a warningin December 2010 to Smith & Nephew for this component. Specifically, Smith & Nephew did not follow protocol in documenting manufacturing procedures, including sterilization of the product and machine settings used to manufacture the titanium rings in various ceramic inserts. The FDA also noted that batches of the products did not meet minimum sterilization requirements. The FDA concluded that these practices and others were “not in conformity with the Current Good Manufacturing Practice (CGMP) requirements.”
Smith & Nephew LawsuitsAlmost 4,000 of the R3 Acetabular metal liners were used in the United States between 2009 and the June 1, 2012, recall. Because of its metal liner, people who received this implant have suffered a number of complications. Studies have already shown that a high number of R3 Acetabular Systems with the metal linerfailed prematurely and required revision surgery.
[From connie: note this is not a recall notice for the R3. This article is merely pointing out some potential issues with this device.]