Intraarticular hyaluronic acid injections are one of the treatment options for knee osteoarthritis.1 What do we know about the effectiveness of hyaluronic acid for the hip? Have hyaluronic acid injections been studied for other joints or is it primarily used to treat knee osteoarthritis?
Hyaluronic Acid Injections Are FDA-Approved for Knee Osteoarthritis but Not for Hips
Hyaluronic acid injections have been FDA approved for many years as a treatment for knee osteoarthritis. But the American College of Rheumatology recommends against the use of hyaluronic acid in patients with hip osteoarthritis.2 Nevertheless, some doctors have been using it off-label as hip injections for their patients. For example, Blue Cross/Blue Shield medical insurance considers intra-articular injections of hyaluronic acid in any joint other than the knee to be investigational and not medically necessary. Researchers have studied the effectiveness of hyaluronic acid injections for the hip and the results were inconclusive.
Hyaluronic Acid Ineffective for Hip Osteoarthritis
Hyaluronic acid aims to restore the normal properties of the synovial fluid. It has also been suggested that hyaluronic acid may protect the cartilage, and reduce the production and activity of inflammatory chemicals (such as pro-inflammatory mediators, matrix metalloproteinases).
According to one study, a single injection of hyaluronic acid is not effective for hip osteoarthritis, actually, no more effective than placebo.3 Because hyaluronic acid is rapidly cleared from joints, more than one injection could be needed to provide benefit. Rapid clearance of hyaluronic acid is just one theory of why multiple injections may produce a better result.
Studies that looked at the effectiveness of hyaluronic acid for hip osteoarthritis have been small and scarce. More studies are needed to determine if hyaluronic acid is a suitable treatment option for joints other than the knee.
Hyaluronic Acid Injections Also Falling Out of Favor for Knee Osteoarthritis
The 2019 guidelines by the American College of Rheumatology conditionally recommend against the use of intra-articular hyaluronic acid injections for knee osteoarthritis.2 Based on a review of 15 studies, the American Academy of Orthopedic Surgeons (AAOS) issued new recommendations in June 2013 saying hyaluronic acid doesn’t meet minimum clinically important improvement measures.4 This may lead to fewer and fewer doctors using these injections for knee osteoarthritis.