Doctors and investigators involved in the DePuy hip recall have been particularly interested in the effects of two metals present in the ASR hip replacement device – cobalt and chromium. The general working hypothesis in the recall case at this time is that the movement of metal on metal in these replacement joints causes small particles of the metals to shed over time, allowing the buildup of these substances in the patients’ tissues and bloodstreams. This eventually leads to heavy metal toxicity, causing the death of many tissues surrounding the affected joint, leading to increased pain, decreased mobility, and ultimately to prosthesis failure.

Take the case of Katie Ayers, a Florida resident who received the ASR device at age 36. Prompted by increasing pain and a gradual loss of mobility, Katie was talked into receiving the ASR device by an eager physician. “It was supposed to be the latest and greatest. It was supposed to be perfect for a younger female and it all sounded great to me,” Ayers reported to CBS.

Later, when Ayers learned that the device was undergoing a recall, she went to her physician for testing and counseling about what steps to take. Blood tests showed elevated levels of Chromium and Cobalt in her blood, consistent with the pattern found in other patients who had received the ASR device. At the time, Ayers did not report any particular symptoms of pain, so it is likely the degradation in her unit was caught and dealt with early. She has since received an alternative hip replacement, though she had thought she would not need such an operation for another 15 or 20 years.

What Ayers’ case shows is that the symptoms associated with the chromium and cobalt toxicity from degrading ASR or other metal on metal hip replacements do not start immediately. It apparently takes time for the toxicity to build to a level that causes the pain and degraded motion experienced by other victims of prosthesis failure. This means that the damage could be developing for some period of time without a patient noticing any outward symptoms.

Tagged as: Depuy hip recall, Prosthesis Failure