WEDNESDAY, Aug. 18 (HealthDay News) -- People whose knees face
outward may be at increased risk for osteoarthritis, new findings
This outward-facing knee alignment -- in which the knees are
relatively far apart and the ankles closer together -- is called
the varus alignment. While it resembles bowleggedness, it's not as
extreme, the study authors pointed out in a news release from the
U.S. National Institutes of Health.
The study included 2,713 volunteers, aged 50 to 79, who had
arthritis or were at increased risk for osteoarthritis because they
were overweight or had a previous knee injury. Osteoarthritis is a
painful -- and sometimes disabling -- condition in which the
cartilage that usually cushions the ends of bone at the joints
The researchers took X-rays of each participant's legs at the
start of the study and again 2.5 years later.
People with the varus alignment were nearly 1.5 times more
likely to develop osteoarthritis than those with a straight-legged
stance. There was no increased risk for people with inner-facing
knees (valgus alignment), the investigators found.
The study, funded by the U.S. National Institutes of Health, was
released online in advance of publication in an upcoming print
issue of the journal
Annals of the Rheumatic Diseases.
According to the first author of the study, Dr. Leena Sharma of
Northwestern University's Feinberg School of Medicine in Chicago,
about 70 percent of the force transmitted to a healthy knee while
walking is focused on the inside of the knee. Therefore, when the
knee faces outward, as in the varus alignment, there is even
greater stress on the inside of the knee, which may increase the
risk of osteoarthritis.
"Our results suggest the need to design interventions for people with varus alignment, in hopes of redistributing stress and possibly helping to prevent knee arthritis before it develops," Sharma stated in the news release.
Osteoarthritis of the knees affects 6.1 percent of all adults
over 30 years of age, the U.S. Centers for Disease Control and
Prevention has reported.
The U.S. Agency for Healthcare Research and Quality has more