DEAR DR. ROACH: My wife is in dire need of knee replacements (arthritis, and bone on bone) but she is allergic to nickel, which is found to some degree in all metals -- including titanium -- used in replacements. Is there any solution to this problem? -- R.B.
ANSWER: Nickel allergy varies in severity, and a lot of people have it. Not everyone diagnosed with a nickel allergy really has a nickel allergy.