The FDA further noted that patients who are at risk for “increased device wear and/or adverse local tissue reactions should be followed more closely.” Those identified as being at higher risk are:
- Patients who are overweight or with high levels of physical activity;
- Patients with bilateral implants, resurfacing systems with small femoral heads (44 mm or smaller), suboptimal alignment of device components or suspected metal sensitivity (e.g., cobalt, chromium, nickel);
- Patients taking high doses of corticosteroids;
- Patients who have evidence of renal insufficiency; and
- Patients with suppressed immune systems.
“As a practicing rheumatologist, I would say [that for] any patient you see who has new-onset thyroid disease or unexplained heart failure and [has] either a metal-on-metal or metal-on-polyethylene joint, think about metal poisoning,” Dr. Bunning recommends. For rheumatologists, if a patient with an artificial hip has hip pain, “the usual reflex is to send [the patient] back to the orthopedic surgeon,” he says. However, rheumatologists also may opt to order a cobalt level or MRI with the appropriate sequences. If cobalt levels come back elevated or the MRI is abnormal, he says, it’s appropriate to work together with the orthopedic surgeon to manage the patient’s treatment.
Kimberly J. Retzlaff is a medical journalist based in Denver.
Acknowledgment: The author and The Rheumatologist thank Dr. Bunning for his assistance in the development of this story.
- Allen LA, Ambardekar AV, Devaraj KM, et al. Clinical problem-solving. Missing elements of the history. N Engl J Med. 2014 Feb 6;370(6):559–566.
- Dahms K, Sharkova Y, Heitland P, et al. Cobalt intoxication diagnosed with the help of Dr. House. Lancet. 2014 Feb 8;383(9916):574.
- CBS Evening News with Scott Pelley. Feb. 7, 2014. https://archive.org/details/WUSA_20140207_233000_CBS_Evening_News_With_Scott_Pelley#start/1260/end/1320.
- Kolata G. As seen on TV, a medical mystery involving hip implants is solved. The New York Times. 2014 Feb 6;A7.
- Family practice. House M.D. Feb 7, 2011. http://www.imdb.com/title/tt1726372.
- Cobalt poisoning. MedlinePlus. http://www.nlm.nih.gov/medlineplus/ency/article/002495.htm.
- Morin Y, Daniel P. Quebec beer-drinkers’ cardiomyopathy: Etiological considerations. Can Med Assoc J. 1967;97(15):926–928.
- Mao X, Wong AA, Crawford RW. Cobalt toxicity—an emerging clinical problem in patients with metal-on-metal hip prostheses? Med J Aust. 2011;194(12):649–651.
- Cooper HJ, Della Valle CJ, Berger RA, et al. Corrosion at the head-neck taper as a cause for adverse local tissue reactions after total hip arthroplasty. J Bone Joint Surg Am. 2012;94(18):1655–1661.
- FDA safety communication: Metal-on-metal hip implants. U.S. Food and Drug Administration. Jan. 17, 2013. http://www.fda.gov/medicaldevices/safety/alertsandnotices/ucm335775.htm. Accessed May 26, 2014.