Uneven Leg Length May Cause Knee Osteoarthritis
About half the population has one leg shorter than the other, a trait that, while common, is often not diagnosed or corrected. Researchers at Queen’s University believe uneven leg length may be a cause of knee osteoarthritis which, if recognized, could be prevented.
The study in which the leg length discrepancy figure was offered was published more than 25 years ago. In it, the author was evaluating the difference in 798 patients who had chronic and treatment-resistant low back and hip problems. He found that when the leg length inequality was corrected using a simple shoe lift, the majority of patients achieved permanent and nearly complete elimination of their symptoms.
In the new study from Queen’s University, co-author and adjunct professor Derek Cooke notes that if pediatricians identify a leg length discrepancy early in a child’s bone development, it could be possible to stop or delay the progression of osteoarthritis later in life.
Cooke and his colleagues evaluated the x-ray images from more than 3,000 adults aged 50 to 79 who were participants in the Multi Centre Osteoarthritis Study. All of the subjects had either knee pain or risk factors for knee osteoarthritis. The researchers discovered that osteoarthritic changes in the knee were most prominent in individuals who had more than a 1-centimeter discrepancy in leg length.
Identifying whether one leg is shorter than the other can be difficult, especially when the difference is only a centimeter or two. Clinicians can perform a standing weight-bearing examination as well as x-rays, which are the best way to determine leg length discrepancy.
Cooke notes that although it is unclear whether leg length discrepancy directly causes osteoarthritis, people who learn they have one leg shorter than the other can take steps to prevent possible problems in the future. Heel lifts and orthotics are two possible and simple ways to correct uneven leg length, ways that could reduce or eliminate the risk of developing osteoarthritis.
Friberg O. Spine 1983 Sep; 8(6): 643-51
Queen’s University news release, Mar. 31, 2010