Osteoarthritis (OA) of the knee is an inflammation of the joint which is caused by the cartilage degenerating. The condition is sometimes linked to knee injuries, obesity or ageing and it can also run in families. To improve patients´ quality of life and minimise disability, effective pain control is necessary.
A variety of oral nonsteroidal anti-inflammatory drugs (NSAIDs) and injectable therapies are available, but reliable comparisons between them are limited. A recent study sought to take away some of the uncertainty and establish which treatments work best.
The research involved a systematic review and network meta-analysis of 137 previous studies which included a total of 33,243 participants. This allowed investigators to quantify the relative effectiveness of common treatments compared with each other and with placebo.
Researchers focused on randomised trials that compared two or more of the following: acetaminophen (Tylenol), diclofenac, ibuprofen, naproxen, celecoxib (Celebrex), corticosteroid injections, hyaluronic acid injections, oral placebo and placebo injections.
Acetaminophen, one of the most commonly used over-the-counter treatments for knee OA, was found to be the least effective option for pain relief after three months. Except for celecoxib, all treatments were significantly better than acetaminophen.
Overall, injections proved to be the most effective treatment for knee OA pain. Sometimes even the placebo injections were more effective than the oral NSAIDs, suggesting that there was a placebo effect linked to the delivery method.
The review, which has been published in Annals of Internal Medicine, concluded that all treatments except acetaminophen showed clinically significant improvement from baseline pain. The biggest benefit came from injections of hyaluronic acid.