Misaligned Knees May Speed Up Osteoarthritis
Being moderately bowlegged, knock-kneed exacerbates effect of weight gain, study finds
THURSDAY, Dec. 2, 2004 (HealthDayNews) -- Leg alignment may influence the benefits of weight loss for people with knee osteoarthritis, says a study in the December issue of Arthritis & Rheumatism.
To better understand the impact of body weight on knee osteoarthritis, the Boston University researchers looked at limb malalignment, an important predictor of osteoarthritis progression. Limb malalignment (bowlegged or knock-kneed) is defined by joint space loss at the point where the shin and thigh bones connect to the knee.
The researchers examined 394 knees with osteoarthritis and found that weight had a major impact on disease progression. For each two-unit increase in body mass index (BMI), there was an 8 percent risk of knee osteoarthritis disease progression. However, this increased risk was limited to moderately malaligned legs.
Neutrally aligned legs or severely malaligned legs had no measurable effect on the risk of osteoarthritis progression.
"The effect of BMI on progression was different at different levels of alignment, with the risk being much greater for limbs with moderate malalignment," study author Dr. David T. Felson said in a prepared statement.
"Our findings, which need to be confirmed in other studies, suggest that prevention and treatment efforts for obesity and knee [osteoarthritis] could be efficiently targeted to those subjects with moderate malalignment. These findings may have broad implications not just for the effect of body weight on [osteoarthritis], but for other risk factors that affect joint loading," Felson said.
The American Medical Association has more about knee osteoarthritis.