A new study released this week showed that knee replacements are holding up remarkably well after two decades, with zero implant failures reported over the course of 20 years.
The study of more than 1,757 total implant procedures performed between 1975 and 1989 was unveiled at the 2011 Annual Meeting of the American Academy of Orthopaedic Surgeons. (It did not include metal-backed patellar implants.) The researchers followed 128 patients from the original cohort two decades after their procedures, finding a “dramatic reduction in knee pain and a significant improvement in the ability to perform common activities.” Most patients said they were able to walk at least five blocks and only three were considered “household-bound.”
The study did not list any disclosures, which will be released at a later time.
Meanwhile, metal-on-metal hip implants are getting still more scrutiny. The Food & Drug Administration raised alarms this week about components of the implants, which have drawn significant notoriety and a number of lawsuits in recent months.
The FDA advises patients with the implants to keep an eye out for symptoms including "hip/groin pain, local swelling, numbness or changes in your ability to walk."
“Metal-on-metal hip implants, like other types of hip implants, are known to have adverse events including infection and joint dislocation. There are some case reports of the metal particles causing a reaction around the joint, leading to deterioration of the tissue around the joint, loosening of the implant and failure of the device, as well as some of the symptoms described above. In addition, some metal ions from the implant may enter into the bloodstream. There have been a few recent case reports of patients with metal-on-metal hip implants developing a reaction to these ions and experiencing medical problems that might have been related to their implants, including effects on the nervous system, heart and thyroid gland,” according to the federal watchdog agency.
One metal-on-metal implant, made by Johnson & Johnson subsidiary DePuy Orthopaedics, issued a recall of its ASR line of hip replacement devices, which have metal-on-metal components.