Gender Differences in Knee Osteoarthritis
Why are women at higher risk for developing severe knee osteoarthritis? Let’s face it: Men and women are built differently. All the way down to the shape of our knees, the alignment of a woman’s leg is much different than the alignment of a man’s leg. Women have wider pelvic bones, greater hip angles, and tend to have a knocked-knee (genu valgus) alignment of the knee. In addition to differences in leg alignment between the sexes, muscle strength varies greatly, too. In general, men are stronger than women; thus, the joints like the knee are not as well-supported in women. It’s no surprise, then, that the gender differences found in the lower extremities can explain the numerous gender differences associated with knee osteoarthritis. (1)
Statistics show that women are not only at higher risk for developing severe knee osteoarthritis; women are also at higher risk for needing a total knee replacement. The need for a total knee replacement is prompted by the fact that women report more disability and pain than men when afflicted with knee arthritis. After having the knee totally replaced, one study showed significant differences in the way women walked and moved. (2) (3)
In order to capitalize on these gender differences, gender-specific solutions should be considered. Because women tend to have less muscle support for the knee, early intervention in the form of physical therapy is critical. Strengthening two key areas in the lower extremities can greatly improve knee function. The hip abductors in the buttocks help to maintain better alignment in the leg, and the quadriceps muscles help to support the knee alignment and function. Both muscle groups should be targeted in women as soon as a knee problem arises. The earlier the knee exercise program begins, the less likely a total knee replacement will be needed.
Biomedical companies have tried to capitalize on these gender differences, as well. Gender specific knee prosthesis’ are available. However, these “custom,” female-specific prosthesis’ have not been proven to improve outcomes and appear to be more of a marketing trick. No matter what type of implant is used, women with severe osteoarthritis usually greatly benefit from a new knee. (4)
The gender differences are not to be taken lightly, especially when it comes to early treatment of knee osteoarthritis. Because of differences in leg alignment and muscle strength, women with knee arthritis can greatly benefit from a gender-specific rehabilitation plan in order to avoid surgery.
1) Arch Phys Med Rehabil. 2014 Dec;95(12):2376-81
2) J Arthroplasty. 2015 Jan;30(1):118-25
3) Osteoarthritis Cartilage. 2014 Aug;22(8):1129-35
4) Clin Orthop Relat Res. Nov 2008; 466(11): 2612–2616
Christina Lasich, M.D., wrote about chronic pain and osteoarthritis for HealthCentral. She is physiatrist in Grass Valley, California. She specializes in pain management and spine rehabilitation.