Joint Replacement News:

FDA Approves First Knee Replacement Shaped to Feel More Natural to Women

The first knee replacement shaped to fit a woman's anatomy was approved on May 10th by the U.S. Food and Drug Administration (FDA), and it will be available for use by orthopedic surgeons almost immediately.

Zimmer, which has provided replacement knee implants for more than 5 million patients worldwide, said its Gender Solutions High-Flex Knee was designed based on three distinct and scientifically documented shape differences between women's and men's knees.

"Even though most women are happy with their results after joint replacement, some still have residual pain in the front of the knee around the kneecap, or say their artificial knee just doesn't feel or move the way their own knee did when it was healthy," said Dr. Robert Booth, Chief of Orthopaedic Surgery at Pennsylvania Hospital and one of the new knee's developers.

Nearly two-thirds of the more than 400,000 annual knee replacement patients are women, according to the National Center for Health Statistics, and the numbers continue to increase each year.

Research shows that women , however, are three times less likely than men to undergo the procedure, although they suffer from more knee pain.

"Knee implants have been functioning very well for men and women, but we want to meet women's unique needs by making knee replacements that feel, fit and function even better," Booth said.

Booth and several other surgeons who helped with development will be implanting the Gender Solutions Knee in patients this Spring, and Zimmer said the implant will be available globally this Fall.

"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," said Booth.

"Women can wear men's clothing and shoes, but most prefer clothing and shoes made for them. That's because women are shaped differently than men. 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," Booth added.

The Gender Solutions High-Flex Knee Implant addresses the following three research-documented, shape-related differences of a woman's knee:

1. Narrower Shape, Proportioned to Female Anatomy: Women's knees typically are narrower from side to side, and are more trapezoid-shaped, whereas men's knees are more rectangle-shaped.

2. Thinner Shape: The bone in the front of a woman's knee is typically less prominent than in a man's knee.

3. More Natural Tracking: The angle between the pelvis and the knee affects how the kneecap tracks over the end of the femur as the knee moves through a range of motion. Women tend to have a different angle than men due to their specific shape and contour.