Hyaluronic Acid Injections
Hyaluronic acid is a naturally occurring substance in joint fluid. It helps to lubricate the joint and absorb some of the shock associated with joint loads. Individuals with osteoarthritis have been shown to have a lower concentration of hyaluronic acid in their joint fluid.
The theory is that supplementing the joint with hyaluronic acid will restore some of the lubrication. It can be administered in a single injection or a series of injections. Many patients note pain relief and improved function after their injections. Typically results last for 6 months or more. Injections can be safely repeated every six months or until they are no longer effective. Injections are FDA approved for use in osteoarthritis or the knee. The most common adverse event is pain at the injection site, which is generally short-lived. More serious adverse events such as joint swelling or redness have been reported.
Stem Cell Injections
I support the position that biologic therapies, including stem cell and PRP injections, cannot currently be recommended for the treatment of advanced hip or knee arthritis. With unproven benefits, high out-of-pocket costs for patients, and clear safety concerns, I do not support the routine clinical use of these therapies. While I do recognize the potential benefit of biologic therapies, current understanding of their application in patients is insufficient to support its use.
Currently, a large number of orthopaedic and medical offices are offering intraarticular injections of stem cells and/or platelet rich plasma (PRP) to patients with advanced hip and knee arthritis. They rely on patient testimonials and expert opinions to support their position that this treatment constitutes an alternative to major surgery. They market these claims directly to the public, with promises unsupported by scientific evidence of their effectiveness. Unfortunately, these treatments are not standardized, often not FDA approved, and result in significant out of pocket cost to the patient as they are not covered by health insurance.
I have treated dozens of patients who fell victim to these false claims. These are vulnerable people with advanced osteoarthritis who were promised a cure for their arthritis. When it was ineffective, they were offered a “booster” for an additional fee.
Osteoarthritis is a slowly progressive degenerative disorder that involves damage to joint cartilage, structural changes in bone, and inflammation of the soft tissues around the joint. Advanced arthritis involves complete loss of cartilage and exposure of damaged bone (so-called “bone-on-bone arthritis”). Unfortunately, there is currently no curative treatment for advanced hip and knee arthritis.
The published literature studying the use of biologics for the treatment of osteoarthritis is evolving. Some evidence suggests that PRP may temporarily improve the symptoms of mild to moderate osteoarthritis of the knee. However, there is little data to suggest it will benefit patients with advanced osteoarthritis. Furthermore, there is no data to support the idea that stem cells can sense the environment into which they are injected and repair damaged tissue. The claim that either PRP or stem cells regenerate severely damaged or lost cartilage is not supported by scientific evidence. The limited amount of available scientific evidence is troubling and does not allow an assessment as to whether the potential clinical benefits of such therapies outweigh any potential harms, or if these biologic therapies are more cost-effective than standard treatments such as acetaminophen, oral anti-inflammatory agents or corticosteroid injections.
While the efficacy of these treatments has yet to be established, the potential for harm clearly exists and is likely underappreciated. While PRP is generally considered safe, the injection of any substance in the knee carries the potential for complications including intraarticular infection. Multiple cases of serious harm have been documented following stem cell treatments, and these adverse events are likely underreported given the current regulatory environment. It is paramount that the safety of these treatments be fully established before they can be supported for routine use.
– Adapted from the AAHKS position statement on Biologics for Advanced Hip and Knee Arthritis