By: Shelagh McNally for Knee1
A woman is as young as her knees.
- Mary Quant, Fashion Designer
Female and male anatomy is very different – and women are more susceptible than men to serious knee injuries and chronic kneecap problems – yet they have long had to use knee replacements originally designed for men. Not only are women’s ligaments more flexible but their muscles supporting the knee are not as strong. Researchers at Medsport at the University of Michigan found that women tend to rely more on their front muscles to stabilize the knee during physical activity that the stronger hamstrings behind the thigh. The result is greater knee injuries among women. Aging also contributes to chronic knee pain in women as the cartilage gets worn down and the bones grind together..
|Why the difference?|
Narrower Shape. Women’s knees are typically narrower side-to-side that men’s. Traditional implants are often too wide leading to an implant overhang that presses on ligaments.
Thinner Shape. The bone in the front of a woman's knee is typically less prominent than in a man's knee. Traditional implants can often feel bulky which can cause pain.
Different angles. Women have a different shape and contour than men. The pelvis is wider and this changes the angle of how the kneecap tracks over the end of the femur, known as the Q angle (quadriceps angle) or “tracking angle.” Traditional implants put more pressure on the knee by narrowing the angle and range of motion.
Go to http://www.genderknee.com/ micro/z/ctl/op/global/action/8 to learn more about the Gender Solutions High-Flex Knee.
According to the National Center for Health Statistics, close to 400,000 Americans had knee replacement surgery last year, and nearly two-thirds were women. While knee surgery has come a long way, the actual device – based on a male knee – has not changed that much since it was developed in the 1960s. And that’s where the problem begins. Studies have shown that a knee implant lasts about 15 years but that women report more problems with the feel, fit, and function of the implant. Problems include pain and difficulty moving the knee. In some cases, another operation is needed.
Those problems may now be a thing of the past. Recently the FDA approved an innovative high-flex knee replacement designed specifically for women. The Gender Solutions High-Flex Knee, made by Zimmer, Inc, was developed by a group of surgeons at the Rush University Medical Center in Chicago Illinois, using three distinct and scientifically documented shape differences between women's and men’s knees.
“Mounting research indicates that a woman’s knee is not simply a smaller version of a man’s knee. The differences involve the bones, ligaments and tendons in the joints,” says Dr. Aaron G. Rosenberg, one of the surgeons on the project. “Women can wear men’s clothing and shoes, but most prefer clothing and shoes made for them. It’s the same with knees, and it makes perfect sense to design knee implants with women in mind, particularly considering that women are by far the majority of the knee replacement patient population.”
This new gender specific knee addresses the shape-related differences typical of a woman's knee: a narrower shape, thinner shape, and the need for more natural motion for the knee when walking. It’s already proving to be a success.
On May 10, 2006, Rosemarie Brinkerhoff of Lovelle, Wyoming received one of the first Gender Solution Implants at LDS Hospital in Salt Lake City. She was one of the first women to receive the new knee. “I'm very grateful to Dr. Bertin and LDS Hospital for the wonderful care that I've received. I feel very fortunate to be able to benefit from this advanced technology,” said Brinkerhoff.
On September 14, Robert E. Booth, Jr., M.D., Chief of Orthopaedic Surgery at Pennsylvania Hospital, Philadelphia, PA, also implanted the Gender Solution and it was broadcast live. The implant is expected to be globally available this fall.
Watch a live broadcast of the September 14, 2006 surgery at: http://www.or-live.com/zimmer/1602/index.cfm.