Overview: Higher levels of cobalt and chromium were found in patients with metal disc arthroplasty, according to a new study published in the European Spine Journal. Helio reports that the levels of cobalt and chromium are similar to those seen in patients with metal-on-metal hip implants.
- A study took blood samples from patients with metal disc arthroplasty over 36 months and found that levels of cobalt and chromium were elevated
- Elevated cobalt and chromium ion levels are also an issue for patients with metal-on-metal hip implants
- When the surfaces of an all-metal hip replacement rub together, metal ions are shed into the body; this is associated with a series of complications
Cobalt and Chromium Levels Similar to Metal-on-Metal Hip Implants
Researchers took blood samples from 24 patients with a single level metal-on-metal lumbar disc arthroplasty through 36 months. The levels of cobalt and chromium were similar to those seen in patients with “well-functioning” metal-on-metal hip implants. There were 13 men and 11 women in the study with average age of 41 years. The patients were implanted a Maverick Lumbar Disc, manufactured by Medtronic. Lead author Matthew F. Gornet, MD and his colleagues stated that “In general, these results indicated that serum Co [cobalt] and Cr [chromium] levels are elevated at all postoperative time points,”
Metal-on-Metal Hip Implants and Elevated Metal Ion Levels
Metal-on-metal hip implants can shed metal ions into the body when the surfaces of the implant rub, or articulate, together. This can lead to a series of complications, including metallosis, pain, swelling, tissue necrosis and early revision surgery. In fact, metal-on-metal hip implants have come under increased scrutiny due to reports showing that these hips fail more often than other types of hip replacements. Concerns peaked in 2010 when DePuy Orthopaedics issued a worldwide recall of their DePuy ASR hip implants due to a high failure rate. In March, a study in the Lancet confirmed that metal-on-metal hip replacements failed at a rate of 6 percent in five years compared to 2 percent seen in metal-on-plastic or metal-or-ceramic implants. In November, a study found a biological explanation as to why metal ions may be causing adverse reactions. Researchers found that the presence of cobalt ions can trigger an immune reaction, causing inflammation and pseudotumors.