Metal Ion Serum Concentrations in Patients With Total Hip Replacements

Cobalt, Chromium and Titanium Serum Concentrations in Patients With Metal-on-Metal vs. Metal on Polyethylene Total Hip Replacements

Other research studies have shown that the levels of metals in the blood are slightly increased after patients receive a total hip replacement. We want to learn whether these elevated levels are associated with any adverse effects. We hope this study will help us identify which type of patients have elevated levels of metal in their blood.

It is suspected that the concentration of the metals chromium, cobalt and titanium in the blood will be higher in people with an all metal total hip prosthesis than in those with a plastic and metal prosthesis. To find out if this is true, we will test blood samples for the levels of metal in the blood and compare the values from 3 groups of people:

1. people with metal on metal hip replacements
2. loosening of a plastic and metal prosthesis and
3. evidence of osteoarthritis and are awaiting a total hip replacement.

Inclusion Criteria:

Group 1 - unilateral hip replacement with metal on metal prosthesis, well functioning.

Group 2 - loosening of plastic and metal prosthesis Group 3 - osteoarthritis of the hip and awaiting total hip replacement

Exclusion Criteria:

• renal dysfunction
• other types of metal implants or dental prostheses
• rheumatoid arthritis
• hip infection