According to the National Center for Health Statistics, the number of knee replacement surgeries increased by more than 50 percent from 1999 to 2003, and that number continues to rise. Why such a dramatic increase? In general, we’re healthier and living longer, with the added years causing more wear and tear to our joints. And, of course, the vast legion of baby boomers is moving through middle age toward what they fully expect to be very active “golden years.” You can be sure that they won’t let worn-out joints limit their lifestyle. So, what used to be an exceptional procedure is now becoming commonplace, and it’s fueled not only by demographics, but by a gradual departure from the original “one size fits all” design of the knee replacement implants themselves.
“Even though the popular press would have the public think that gender-specific knee replacement is revolutionary, it’s really just a further evolution of design,” explains Doylestown Hospital orthopedic surgeon Charles B. Burrows, MD. “Originally, there was just one design, and it was used for both the right and the left knee. Then the design evolved so that different implants were available for right and left, and further design modifications followed that. I see “gender-specific” implants as simply part of that continuum.”
What makes them different?
Gender-specific knee replacement implants are proportioned
to fit the average female anatomy. The knee joint of
the average woman is taller and narrower than a man’s, is
not as thick in the front, and the angle at which the knee
works – the Q angle – is different. The Q angle represents
the angle of the femur, or thigh bone, which is greater in a
woman because her hips are wider than a man’s. “Although
the size and design of the new gender-specific knee
replacement implants are not tremendously different from
the range of designs previously available to us,” says Dr.
Burrows, “they do give us more options for providing our
patients with the best fit and potentially greater comfort
following their knee replacement.”
According to Dr. Burrows, the average age for knee replacement in his practice is between 55 and 60. This may be surprising, but, says Dr. Burrows, “Patients are opting for surgery sooner rather than later. For many, it’s a lifestyle decision. They’ve exhausted nonsurgical options such as medication and physical therapy and they’re not willing to settle for a life of significantly restricted physical activity. “In addition,” he continues, “about 90 percent of today’s patients can expect their implants to last for about 20 years, so the notion of waiting until you’re quite a bit older in order for your knee replacement to ‘last’ is generally not an issue anymore.”
Despite the marketing hype, orthopedic surgeons continue to select implants based on the criteria they’ve always used – they choose what’s best for the patient. That means that a so-called “gender-specific” implant may, in fact, be the best choice for a particular man’s anatomy. Or the wider, thicker implant may be right for a particular woman. The real news is that there are now more options for all of us as we stride…golf…bowl…dance our way into the years ahead.
Dr. Charles Burrows is with Mackell/Cody/Burrows Orthopaedics and Sports Medicine.
