Could an MRI Help Predict Potential Failure of Stryker and Other All-Metal Hip Implants?

The recent rash of metal-on-metal hip device recalls as well as the ensuing lawsuits against manufacturers who appear to have more interest in profits than in patient safety were the topic of discussion at a March 19, 2013 meeting among orthopedic surgeons. This conference, held in Chicago, of the American Academy of Orthopedic Surgeons centered on determining whether judicious use of MRIs could predict soft tissue damage in hip implant recipients before irreparable damage was done.

While the FDA has issued updated guidelines for recipients of all-metal or partial metal hip implants which recommended regular physical exams, blood testing, x-rays and MRIs, many patients are not receiving the MRI test. Any unusual pain and swelling in the hip area following artificial hip implantation is cause for concern and may indicate device failure. Research done on seventy patients who underwent revision surgery for replacement of a defective hip device was discussed by the physicians at the AAOS conference. This research indicated that the superior imaging capabilities of the MRI could more easily identify early tissue damage among implant recipients.

Such early identification can minimize the levels of tissue necrosis and bone loss prior to the revision surgery. When extensive bone and tissue loss is present, revision surgery becomes much riskier for the patient and much more challenging and complex for the orthopedic surgeon. Although metal-on-metal hip implants as well as the designs which implement partial metal components—such as the Stryker Rejuvenate and ABG III—were marketed as providing extended life and greater durability for patients, those promises have not materialized.

Metal implants which were believed to be superior to their ceramic and polyethylene counterparts have been shown to exhibit early failure as well as serious, long-term injuries and illnesses. When microscopic metal ions shear away from the metal components during periods of activity, those tiny cobalt and chromium shards can lodge into surrounding tissues or enter the bloodstream of the patient. Inflammation, chronic pain, tissue necrosis and bone loss as well as symptoms of metal toxicity can occur. Cobalt and chromium toxicity can lead to:

·         Neurological, cardiovascular, renal, thyroid and gastrointestinal disorders

·         Depression, anxiety, irritability

·         Memory loss, vertigo and other balance issues

·         Skin problems

·         Vision and hearing loss

·         DNA disruption

·         The development of pseudotumors

A statement issued at the conference recommended early evaluation for patients with metal hip replacements. Earlier recognition and evaluation of patients with metal hip replacements can allow treatment prior to significant levels of damage to the patient. Specific treatments and diagnostic methods used when patients experience pain and discomfort were also detailed by the AAOS as well as a time frame for beginning treatment and performing revision surgery. The FDA’s updated guidelines have proposed new regulations which would require clinical trials and proof of implant safety prior to marketing hip implants to consumers. This is considered to be a positive step in holding hip implant manufacturers responsible for deficiencies and dangers in their hip devices. The bottom line for those with a metal hip implant is that an MRI can potentially detect tissue and bone damage before it has reached extreme levels.