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THA performed with large metal heads yielded greater incidence of cobalt, chromium ion levels
Recently published results showed a greater incidence and magnitude of cobalt and chromium ion levels among patients who underwent total hip arthroplasty with a large metal heads compared with ceramic heads. All patients in the study had a tapered-wedge femoral stem made of titanium, molybdenum, zirconium and iron.
Researchers measured cobalt, chromium and nickel ion levels among 60 patients who underwent a non-cemented total hip arthroplasty (THA) with an Accolade TMZF (Stryker) between June 2014 and January 2015. All THAs were performed with either a 32-mm or 36-mm metal or ceramic femoral head coupled with highly crosslinked polyethylene.
Results showed patients with metal heads had detectable cobalt and chromium levels, with a mean cobalt level of 2 g/L in 56.7% of patients and a mean chromium level of 0.3 g/L in 16.7% of patients. Researchers noted cobalt and chromium levels were nondetectable in all patients with a ceramic head.
Patients with metal heads had significantly higher cobalt and chromium levels vs. ceramic heads. Researchers also noted patients with 36-mm metal heads had significantly higher cobalt levels vs. patients with 32-mm heads. While all patients who underwent THA with a ceramic head were asymptomatic, researchers found mild hip symptoms in seven patients who had metal femoral heads. Of these, four had positive findings of early adverse local tissue reaction on MRI. – by Casey Tingle
Disclosures: White reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.