New research shows that medicated relief from osteoarthritis pain doesn’t always have to come in a pill. Instead, doctors in Connecticut have found that a topical cream, rubbed on the affected joints, eases pain and improves patients’ functional performance and quality of life.The cream contains a (CFA) cetylated fatty acid, such as those in fish oils, which has been shown to reduce arthritis symptoms when taken orally. The study conducted by Dr. William Kraemer and colleagues, of the Department of Kinesiology at the University of Connecticut, was among the first to investigate the effectiveness of cetylated fatty acids—applied as a cream, directly to the surface of the knee joints.
The cream used in the study is called Celadrin, and was provided by Imagenetix, Inc. It is different from the typical drug store menthol muscle rub creams in that it contains these cetylated fatty acids.
"The key is not the menthol, but the fatty acids," said Dr. Kraemer.
Many creams are marketed as containing cetylated fatty acids, but this was one of the first published studies to test the cream’s effectiveness in improving functional mobility in patients with knee osteoarthritis, or OA. The results are in the April 2004 issue of the Journal of Rheumatology.
When arthritis pain develops, the typical response by patients is to reduce activity, which in turn reduces muscle strength and can lead to weight gain, which can worsen OA. Therefore it’s important for patients to find an intervention that allows them to keep moving — whether that is with medications like COX-2 inhibitors or non-steroidal anti-inflammatory drugs (NSAID). Unfortunately, these drugs have been shown to increase the risk of stomach bleeds and kidney problems.
This study showed that the cetylated fatty acid creams are another, and perhaps safer, pain-relieving intervention for people with OA.
"It’s very amazing, it’s a nice adjunct, and there are not really any side-effects," said Dr. Kraemer.
The study included 40 patients with knee OA who were randomly assigned to use the cetylated fatty acid cream or a placebo cream that did not contain fatty acids. All patients were brought into the lab for functional testing. Then they were asked to rub the study creams into the front surfaces, sides, and back surfaces of both knees. After 30 minutes each patient was tested for functional performance. The study participants continued to use the creams—not knowing which was real and which was placebo—twice a day for 30 days. Then functional tests were performed again after 30 days.
The researchers found that patients in both the placebo and fatty acid cream groups showed improvement in the test that required getting up from a chair and walking a specified distance, immediately after the cream was applied for the first time and again after 30 days of use. But the greatest reduction in time required to perform the task was observed in the group that used the fatty acid cream. The researchers suggest the slight improvement observed with the placebo cream was due to the relief felt in the joints from the act of massaging it into the knees.
The fatty acid cream also helped the OA patients significantly reduce the amount of time it took them to climb up and down stairs compared to the placebo group. This improvement was observed immediately after the first application and after 30 days of use.
The researchers also observed an improvement in balance in the group that used the fatty acid cream. A test called the unilateral reach—where patients were asked to balance on one foot while extending the other leg out in front—was performed better on both right and left legs by the group that applied the cetylated fatty acid cream for 30 days.
Range of motion was improved and stepping down and up from an elevated surface was also improved in the group that applied the fatty acid cream versus the placebo group.
Therefore, the researchers concluded that a topical cream consisting of a cetylated fatty acid improves knee range of motion, increases patients’ ability to climb stairs and rise from a chair and walk, and the cream increases strength, endurance and improves balance in patients with OA.
The researchers are not exactly sure how the fatty acids reduce pain, but some theorize it might inhibit mediators of inflammation. Inflammation of the joints is a common symptom of OA.
"We have no data regarding the absorption of the CFA cream through the skin and into the joint," the researchers write, "but such studies should be a topic of further investigation."
Dr. Kraemer said that the results of the study support the use of a cetylated fatty acid cream as an adjunct to paint relief treatment for OA.
"Like I tell people, it’s not like taking a pharmaceutical, if it gives you a little pain relief than great," he said.
