Musings of a Compulsive Thinker

"Gender-sensitive" knee implant designs

Apparently this is the next big thing in TKA (total knee arthroplasty). Back in 2006, both Stryker and Zimmer were touting their latest TKA designs; each claimed to be the first with a design created specifically with the female anatomy in mind.

The resulting debate in business and medical forums provided me with both amusement and annoyance. (Apparently I wasn't the only one rolling my eyes over the whole argument; back in March 2006, when the advertising campaigns for Zimmer's Gender Solutions High-Flex Knee and Stryker's Triathlon Knee System were running in high gear -- both designs were highlighted at the annual meeting of the American Academy of Orthopedic Surgeons -- Colin Barr of TheStreet.com included the marketing tug-of-war in his column, "The Five Dumbest Things on Wall Street This Week.")

The idea of a gender-specific knee is an important step forward in the slowly evolving area of TKA. There are many well-documented differences between the male and female knee, including fat distribution, anatomical alignment, and bone structure; for example, the female femur and tibia are narrower and more elliptical in the sagittal plane. This idea makes a lot of sense to me.

There are skeptics. DePuy and Biomet, for example, have gone on record with the opinion that the anatomical differences between the male and female knee are not sufficient to warrant a gender-specific TKA design. However, I'm still working on digging up any out-and-out refutations of the pro-gender-specific arguments, of which there seem to be no particular shortage.

Further reading:
"The Female Knee: Anatomic Variations" (S. Conley et al.), J. Am. Acad. Orthop. Surg., 2007.
"Total Knee Replacement for Women" [PDF, 3.6 MB] (J.N. Argenson), European Musculoskeletal Review, 2006.
"Gender Specific Knee Replacement Implants" (J. Cluett), About.com Orthopedics, 2007.
"Knee Replacements, Designed for Women" (A. Aubrey), National Public Radio, 2007.

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Labels: engineering, science

posted by the alygator @ 10:47 AM