Public Communication – Health Canada Issued Important Safety Information on Metal-on-Metal Hip Implants

May 9, 2012

Subject: Important Safety Information regarding Metal-on-Metal Hip Implants

Dear patients,

Health Canada has issued a Health Care Professional letter to Canadian orthopaedic surgeons informing them about potential health risks and recommending patient management strategies following metal-on-metal (MoM) hip implant surgery.

MoM hip implants are artificial, implantable hip joints containing a metal ball and metal cup components. These medical devices are used in both total hip replacement (changing the entire hip joint to an artificial hip joint) and hip resurfacing (changing a part of the hip joint) surgeries. In recent years, there has been an increase in awareness of pain, adverse local tissue reactions and implant loosening in patients with MoM hip implants. If the adverse effects become serious, revision surgery may be required to remove the old system and replace it with another one.

• Some of these adverse effects are thought to be the result of increased levels of tiny metal particles and metal ions released by the implant. Metal particles may wear off the device when the metal ball and the metal cup slide against each other during walking and running over time. Metal ions are chemical elements produced by corrosion of the metal.
• Different patients may react to these metal particles and ions in different ways. Typical symptoms are:
  • pain in the groin, hip or leg
  • swelling at or near the hip joint
  • a limp or change in walking ability or limited range of motion
    
• The following factors have been identified to be associated with the increased risk of adverse local tissue reactions:
  • female patients
  • patients with increased activity levels
  • patients who are severely overweight
  • patients with implants in both hips
• Patients who have hip implants and experience the above symptoms should consult their orthopaedic surgeons for additional information.

Managing marketed health product-related adverse incidents depends on health care professionals and consumers reporting them. Reporting rates determined on the basis of spontaneously reported post-market adverse incidents are generally presumed to underestimate the risks associated with health product treatments. Any cases of serious or unexpected adverse incidents in patients with metal-on-metal hip implants should be reported to Health Canada.

Any suspected adverse incident can be reported to:
Health Products and Food Branch Inspectorate
HEALTH CANADA
Address Locator: 2003D
Ottawa, Ontario K1A 0K9
Telephone: The Inspectorate Hotline: 1-800-267-9675

The Medical Devices Problem Report Form and Guidelines can be found on the Health Canada Web site.

For other medical device inquiries related to this communication, please contact Health Canada at:
Marketed Health Products Directorate (MHPD)
E-mail: mhpd_dpsc.public@hc-sc.gc.ca
Telephone: 613-954-6522
Fax: 613-952-7738