Dick Hurckes is tough on his joints. Having trashed his right knee playing football in his youth, and after wearing out two replacements via an active lifestyle, the 69-year-old from Larkspur was confident his fourth knee, implanted in winter 2009, would be a keeper. But a few months after his surgery, “it swelled up to the size of a volleyball,” he says. “I couldn’t even bend it.” After ruling out infection and biomechanical issues, his surgeon referred him to National Jewish Health allergist Dr. Karin Pacheco, who dabbed samples of the implant’s ingredients onto Hurckes’ back. A few patches lit up with rash. Turns out he was allergic to the cement holding his new joint in place. Hurckes was headed back to the operating table.

“This is the tip of the iceberg,” says Pacheco, who specializes in implant allergies. Since 2010, when she got the first call from an orthopedist, she’s tested 500 people, many of whom have had swollen, painful joint replacement sites at their hips, knees, or shoulders. Half of those who’ve seen Pacheco have tested positive for sensitivity to the metal or glue in their implants. Although the majority have in-joint reactions, one was allergic to titanium mesh in his skull, another to the hardware in her vertebrae. In most cases, when surgeons swapped the culprit for a nonallergenic alternative, patients improved.

Of the one million joint replacements performed in this country annually, one-tenth fail. Pacheco believes a chunk of those failures result from allergies and urges orthopedists to be on alert. Some local surgeons, however, question the efficacy of a skin patch test, suggesting that a blood test (only available for a few implant ingredients) is more reliable. Others say the risk is being overblown. “We don’t know for sure that allergies cause joint failure,” says Denver surgeon Dr. Ronald Hugate, who recently convened a meeting of orthopedists to initiate more research. He cautions that just because you’re sensitive to a metal doesn’t mean you’ll react poorly to an implant. But he does warn if cheap jewelry or acrylic nails give you hives, a presurgical allergy test might be “prudent.”

What’s In Your Implant?

Nickel: Nearly 15 to 20 percent of the population is allergic to this silvery-white metal, which is commonly found in cheap jewelry, coins, cellphones, and eyeglass frames.

Cobalt: Do you get a rash from buckles and zippers? You might be allergic to this lustrous gray element.

Methyl methacrylate: This liquid is used in bone cement and in the acrylic in fake nails, but it’s banned in salons in 30 states due to reports of irritation to skin, eyes, and lungs and neurological problems.

Aluminum, copper, titanium, and molybdenum: Allergies to these substances are rare, but they do exist.