Nonsurgical Treatment for Knee Pain: Hyaluronic Acid
Patients with osteoarthritis of the knee usually do not need to jump right to surgery. There are many conservative treatment options a patient can try first. Today, we will discuss Hyaluronic Acid injections. You may have heard of these referred to as “rooster comb” shots or as viscosupplementation. What exactly are these injections and how do they work?
What is Hyaluronic Acid?
Hyaluronic acid is a natural substance found in the body. It is found in highest concentrations in the skin, eyes, and joints. It is a polymer that has high viscoelastic properties and moisture retention (Sze et al. 2016). Studies have shown that patients with osteoarthritis of the knee have lower levels of hyaluronic acid in the synovial fluid. These injections act to help supplement this loss. Hyaluronic acid comes in many different forms. There are oral supplements, topical serums, and injectables. It also has many different indications including treatment for osteoarthritis of the knee, use in ophthalmic surgery, and even cosmetic procedures. Hyaluronic acid has been shown to be most effective when injected directly at the source. In our case injected into an arthritic knee.
Where does it come from and How Does it Work?
It was first isolated by Scientists Karl Meyer and John Palmer in the 1930’s from the eye of a cow. It’s was first used clinically in intraocular lens implants. You can read more about the history of hyaluronic acid here. Today there are two common production methods: extraction from animal tissues (typically the combs of roosters) or produced by bacterial fermentation in a laboratory. Patients with allergy to birds, feathers, or eggs are encouraged to proceed with a non-avian sourced injectable product. Hyaluronic acid helps to lubricate the joint and give it a cushioning sensation. There are several different brands of hyaluronic acid with a varying number of injections. Typically, these injections are done once a week for 3-5 weeks.
What Should I Expect After the Injection?
This is a very routine and quick procedure done right in the office. Our providers utilize ultrasound technology to increase accuracy and decrease pain of the injection. We can directly visualize our target and guide the medication to the appropriate spot without exposing you to unnecessary radiation. The material that is injected is quite viscous, so some patients may experience some short-term soreness of the joint following the injection. We typically advise patients to rest and avoid vigorous exercise for 1-2 days following the procedure.
How long does the relief last?
The effects of these injections can last anywhere from 6 months to a year. There is a wide spectrum of pain relief depending on the patient. These injections are covered by most insurance carriers and can be repeated every 6 months. In some patients, a trial of these injections may help to delay the need for total knee replacement.
Is there data to support its effectiveness?
Hyaluronic Acid is an FDA approved drug supported for it’s use as an injectable treatment for osteoarthritis of the knee. There have been many studies done to support its safety and efficacy.
- A prospective study done in Japan in 2006 found that patients with osteoarthritis of the knee who received serial hyaluronic acid injections noted significant improvement in physical function, pain, and balance.
- In a double blind randomized control trial done in Australia found that scores for pain and stiffness were significantly lower in the Hyaluronic Acid treatment group versus placebo.
- A review done by Louisiana State University shows strong evidence for hyaluronic acid injections when injected into arthritic knees causing reduction in pain and improved physical function for up to 6 months. The review also suggests a very low side effect profile and high toleration rate by patients.
Am I a Candidate for These Injections?
Most patients with knee arthritis can benefit from this type of procedure. Visit one of our skilled San Diego orthopedic providers for an evaluation today to see if you are a candidate for hyaluronic acid injections.