In June 2012, Smith & Nephew recalled the metal socket liner used in its R3 Acetabular hip system. The R3 metal liner was introduced to the market in 2009. It is estimated that about 7,700 have been implanted in patients since 2009. Smith & Nephew claimed that it was “not satisfied with the clinical results” of the liner. It is reported that patients have experienced adverse side effects from the R3 metal liner including infections, dislocations and fractures. There has also been a higher rate of revisions due to evidence of metallosis or metal ion debris.

The clinical data upon which Smith & Nephew is basing its withdrawal of the R3 from the market is the fact that 1.6 % of patients with the R3 will require revision surgery each year. This is above the 1% guideline that has been set by Britain’s National Institute for Health and Clinical Excellence.

The United Kingdom’s Medicine and Healthcare Products Regulatory Agency (MHRA) has issued a medical device alert relating to the recalled R3 metal liner. The alert addressed the “increased rates of revision of MOM hip replacements when using the metal liner component of the R3 acetabular system.” The alert also addressed the fact that the revision percentage associated with the R3 metal liner is not in line with its guidelines. The MHRA asks that patients who have been implanted with R3 metal liner components undergo annual follow up for the life of the implant regardless of whether they are experiencing signs of failure. Importantly, the MHRA is asking that all patients undergo blood testing for metal ion levels which has been a common issue associated with metal-on-metal hip implants, particularly recalled or failed metal-on-metal devices.

Some of the common side effects and complications that might arise from having a recalled or failed R3 metal liner include:

• Increased levels of metal ions
• Increased metal wear rates which may cause metal debris
• Osteolysis
• Necrosis- death of the tissue surrounding the implant
• Severe hip pain due to dislocation or metal wear
• Revision surgery- surgery to remove the failed R3 metal liner
• Pseudotumors

This recall follows in the footsteps of the Zimmer Durom hip implant recall in 2008 and the disastrous DePuy ASR metal-on-metal hip implant recall in August 2010. The recall of the R3 metal liner is the second recall of a metal hip component in 2012. On July 6, 2012, Stryker recalled its Rejuvenate and ABG II modular neck stems in the United States.

Metal-on-metal hip implants continue to pose significant health risks to patients who undergo implantation of these devices. The FDA has expressed serious concern about the benefits of metal-on-metal hip implants and recently asked 21 manufacturers to conduct research on the effects of metal debris and ions on patients with these implants.