Less Lubrication Links Knee Injury to Arthritis
Animal Study Shows Loss of Lubrication May Cause Osteoarthritis
June 8, 2005 -- A knee injury may increase the risk of osteoarthritis in later years by causing lasting lubrication problems.
Based on animal tests, researchers found that knee injuries caused a progressive loss of joint lubrication that may contribute to premature wear of the joints and lead to
Osteoarthritis is a common form of arthritis that usually strikes people later in life and results in joint pain and stiffness. The condition is caused by a gradual loss of joint-cushioning cartilage between the joints.
Although knee injuries and osteoarthritis have been linked before, researchers say these findings offer proof of a possible mechanism.
"In this study, we were able to quantify loss of lubrication, which has important implications for preventing osteoarthritis," says researcher Gregory D. Jay, MD, PhD, research director in emergency medicine at Rhode Island Hospital, in a news release. "If you're walking on a nonlubricated joint, it's very likely you'll develop osteoarthritis or induce damage to other areas of the knee."
Loss of Lubrication May Lead to Osteoarthritis
In the study, which appears in the June issue of Arthritis and Rheumatism, researchers examined the effect of knee injury on joint lubrication in a group of rabbits.
The study showed that the lubricating ability of the joint fluid surrounding the joints was significantly decreased following a knee injury.
Researchers measured the lubricating ability of joint fluid taken from the knee joints up to three weeks after the injury. They found that the concentration of lubricin, a natural substance that protects the joint from wear, significantly decreased in the weeks following injury.
Researchers compared their findings in the rabbits to observations of emergency room patients with knee injuries and found a similar deterioration of lubricating ability due to loss of lubricin.
They say the results indicate that the level of lubricin in the affected joint may be linked to osteoarthritis risk.
"If you injure a joint, or have been injured in the past, it would be useful to have a test that could indicate your level of risk for developing arthritis," says Jay.
Researchers say they've developed a simple test that can be performed in any hospital laboratory to determine lubricin levels.