This Joint’s Gender-Specific

Replacement knees for women only

Newsday—New York—June 27, 2006

Angela Vigliarolo awoke on May 18 to find she’d become a trailblazer, the initial New York recipient of “the first knee replacement shaped to fit a woman’s anatomy,” according to its manufacturer, Zimmer Holdings Inc.

Is the new gender-specific knee really an improvement over the existing armamentarium of artificial knees? Or, as some are suggesting, is this more an attempt to ensure Zimmer’s share of what is fast becoming a highly lucrative medical-products market aimed at the female consumer?

Richard S. Laskin, M.D., is an attending orthopedic surgeon at Hospital for Special Surgery. Laskin said the concept of smaller knee implants is not anything new. He said other companies have devised smaller knees after they studied the X-rays and MRIs of both men and women.

Stryker Corp., a Zimmer competitor, for instance, has its own Triathlon Knee, which it advertises as appropriate for men and women. But, according to Stryker, because it comes in several smaller sizes and has a slightly different shape, it is particularly appropriate for women.

In response to Zimmer’s claim that it is the shape of their gender-specific knee that makes it unique, Laskin said all the smaller implants are smaller proportionately from side to side and from front to back, and “that makes them a narrower shape as well.”

Laskin has been involved in developing artificial knee implants for Smith & Nephew, another manufacturer of orthopedic products. He said that 34 years ago, when he started doing knee replacements, they came in only two sizes.

“We’d kid that they came in ‘too large’ and ‘too small,’” he said. Today, however, Laskin explained, the difference between any two sizes is usually 3 or 4 millimeters, or about a sixth of an inch. “If a person’s bone is in between two sizes, the worst off it’s going to be is 2 millimeters from one size, or about a twelfth of an inch, which from a practical point of view isn’t much of anything.”

“Zimmer has taken a concept – which is real and true but that everyone else has realized for a long time – and they have commercialized it very well,” Laskin said. “That’s fine, and there’s nothing wrong with that, but it’s nothing new. It’s to their credit.”

Laskin, too, foresees gender-specific orthopedic products as a wave of the future.

“Everybody likes to feel something has been made custom for them,” he said. “A woman would like a woman’s shampoo; it’s everything from shampoos to now total knees. Some of it is realistic, but a lot of it is marketing.”

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