The results are from a study by Rhode Island Hospital, University of Rhode Island, and Case Western Reserve University School of Medicine.

"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 author Gregory D. Jay, MD, PhD, research director in emergency medicine at Rhode Island Hospital. "In this study, we were able to quantify loss of lubrication which has important implications for preventing osteoarthritis."

Researchers first looked at rabbits with injured knees. They withdrew synovial fluid surrounding the knee cartilage and measured lubricin. They found that lubricin completely disappeared from the rabbits in three weeks.

An observation of emergency room patients supported many of the findings observed with rabbits. Researchers took a retrospective look at the synovial fluid drawn from injured knees of emergency room patients to alleviate swelling. Overall, there was greater friction than in patients with no injuries. In addition, the study found an increase in production of CII peptides, which indicates early damage to joint cartilage.

At the opposite end of the spectrum, researchers looked at patients with rheumatoid arthritis, chronic inflammation caused by an autoimmune reaction against the body's own tissues. They found that patients with rheumatoid arthritis had no lubricating ability. The findings indicate that the deterioration of lubricating ability and its possible association to cartilage damage "is not a unique feature of early stages of a knee injury, but rather a common feature in inflammatory conditions, both acute and chronic," the paper states.

"Our ultimate goal is to determine how much lubrication is lost after a knee injury. If you're walking on a non-lubricated joint, it's very likely you'll develop osteoarthritis or induce damage to other areas of the knee," Jay says.

MEDICA.de; Source: University of Rhode Island