Hyaluronic Acid Injection for Knee Osteoarthritis: What is it and How Effective is it?

Knee osteoarthritis is a common condition that affects approximately 25% of all adults in the U.S. who are 50 years old or older. The hyaluronic acid injection is a nonsurgical treatment for knee osteoarthritis. This article discusses what hyaluronic acid (HA) injection is and how effective it is at treating knee osteoarthritis.

Hyaluronic acid injection, also known as viscosupplementation, is a safe and effective treatment for knee osteoarthritis. This procedure involves the injection of high viscosity, very thick, slow-flowing fluid into your knees that helps to lubricate them so they can better respond when stressed by activity or overuse injuries or traumas. Unfortunately, as our knees age, they produce less and less hyaluronic acid.

As the scientific paper published in The Journal of Bone and Joint Surgery reports, HA injections in the medical office setting are performed very frequently: “HA injections were responsible for 16.4% of all knee osteoarthritis-related payments, trailing only imaging studies (18.2%), and HA injections accounted for 25.2% of treatment-specific payments, a rate that was higher than that of any other treatment.”

There are different HA brands on the market produced by different medical supply companies: Synvisc, Euflexxa, Orthovisk, Hyalgan, Hymovis, Triluron, Supartz, etc., just to name a few but essentially, they are all the same variants of the hyaluronic acid naturally produced by our knees. All those medications were thoroughly evaluated and approved by the FDA after multiple studies that were able to confirm their benefit. Usually, those injections are given once per week for 2 or 3 weeks (occasionally for up to 5 weeks) with partial or complete pain relief that can last up to 6-8 months on average before a patient requires a repeat HA injection.

Scientists from the Cochrane Collaboration have published a review about hyaluronic acid injections in the knees affected by osteoarthritis. They also made a meta-analysis on more than 76 randomized controlled trials about this topic.

What is a meta-analysis? A meta-analysis is a study of studies, so it is a statistical process that combines many different studies into a single result.

Here’s what a paper published in Orthopedic Review Journal states: “A 2006 Cochrane Review, including seventy-six randomized controlled trials evaluating viscosupplementation with a diagnosis of knee OA in at least one branch, supported the efficacy of viscosupplementation against placebo. The authors report beneficial effects on pain, physical function, and global assessment, with the strongest findings between 5-13 weeks post-injection.”

The most important finding of this review is that hyaluronic acid injections are more effective than placebo in reducing pain and improving function in patients with knee arthritis, at least for the medium term.

1. What is a Hyaluronic Acid Injection?

Hyaluronic acid (HA) is a natural component of the human body. It is released by cells along with other fluids to create the synovial fluid that lubricates and nourishes joints. The degradation of HA in joints can occur due to osteoarthritis or some other form of articular cartilage degeneration.

HA injections are an alternative treatment for osteoarthritic knee pain which involves injecting the synovial fluid look alike (synthetic hyaluronic acid) into the affected joint. Hyaluronic acid is a substance that naturally occurs in the body and easily absorbs water. It provides cushioning and lubrication to joints, tendons, organs, and blood vessels.

2. How Does it Work?

How does hyaluronic acid work for knee injections? Hyaluronan is an important cellular messenger that supports joint mobility and helps protect joints against wear. With its ability to substitute and supplement a diminished amount of hyaluronic acid in the aging knee, hyaluronic acid has been found effective at relieving knee pain by multiple independent scientific studies.

Injections with this substance can provide long-term relief for many patients by stimulating their body's natural healing system and allowing them to live a more comfortable life without having limitations on movement or activities due to joint discomfort.

3. Benefits of the Injection

Knee pain can debilitate a person's life. The viscous supplementation knee injection is an effective way to get rid of this type of discomfort and speed up the healing process, according to several studies done on human subjects over time.

It works by supplying the missing lubrication as well as promoting new tissue growth of the damaged or injured connective tissue inside the knee joint; it also helps the affected knees to recover more quickly after trauma (like sports-related injuries) without having any significant side effects. HA injections are more efficient for mild and moderate osteoarthritis and less so for severe osteoarthritis.

4. How Effective is a Hyaluronic Acid Injection?

Hyaluronic acid injection for knee osteoarthritis is a very safe treatment option. The injections are minimally invasive (small needle injection) and do not require surgery, anesthesia, or recovery time. Patients can return to their everyday activities of daily living immediately after the injection.

5. Side Effects and Precautions

The procedure for a hyaluronic acid injection is quick and easy. Surprisingly, there are few side effects and precautions to consider with hyaluronic acid knee injections.

Less than 2% of people report pain at the site of the injection, which can last for a couple of days after your procedure depending on how sensitive the knee is even before injection as well as other factors such as any previous surgeries in this area. Given the relative infrequency of side effects or precautions to worry about makes this treatment an excellent treatment option for patients suffering from knee pain.

6. Contraindication to Injections

Infection, joint effusion, taking anticoagulants (blood thinners), or allergy are all relative contraindications to those injections. The doctor will need to know if you have any of these conditions before he or she can administer an injection because it could compromise the effectiveness of this treatment.

7. The Cost of the Procedure  

The cost of the hyaluronic acid knee injection procedure can vary depending on your medical health insurance provider but is often covered by the insurance company. Usually, the medical office where you are going to get this injection will ask the medical insurance provider for prior authorization (after which you will be responsible for only a minor portion of the cost of this injection/ depending on your plan’s deductible).

8. Where Can You Find a Doctor Who Provides Hyaluronic Acid Knee Injection Procedures?

The best place to start looking for doctors in your area is by searching online. You will want to ensure that they have experience with injections and procedures such as these before making an appointment so ask about it. You can also start by asking your friends and family members, or your coworkers.

You can also contact an organization like The American Academy of Orthopedic Surgeons (AAOS) for assistance in locating the right practice near you. Frequently, those injections can also be performed by a local pain management doctor. Either way, those procedures are simple, easy and within everyone’s reach.

Findatopdoc.com directory of physicians is also an excellent source of information where you can find a physician who can perform those injections for you. Just look for a physician in your ZIP code.

Conclusion

Hyaluronic acid injection for knee osteoarthritis is an effective way to get rid of this type of discomfort and speed up the healing process. Hyaluronic acid injections are minimally invasive, easy, and convenient. HA injection procedures can be performed by a local pain management doctor as well as other physicians who perform these types of treatments in your area given that they have experience with them already - which you should ask about before making an appointment!

The cost will depend on what kind of medical insurance provider you use but it is often covered depending on any pre-authorization restrictions from your health care company beforehand. Hyaluronic acid injections offer minimal side effects or precautions, so it is an excellent treatment option if you are looking for something easier than surgery or drugs. Hyaluronic Acid Injections also offer almost immediate results and last for many months. Hyaluronic acid injections like these could be what your knee needs to obtain relief from pain and hopefully increase mobility and the quality of your life.

If you want to read more blog posts by Dr. Igor Smelyansky, please click here. 

References

1)      Weick JW, Bawa HS, Dirschl DR. Hyaluronic Acid Injections for Treatment of Advanced Osteoarthritis of the Knee: Utilization and Cost in a National Population Sample. J Bone Joint Surg Am. 2016 Sep 7;98(17):1429-35. doi: 10.2106/JBJS.15.01358. PMID: 27605686. 

2)      https://www.cochrane.org/CD010643/MUSKEL_hyaluronic-acid-and-other-non-surgical-treatment-options-ankle-osteoarthritis 

3)      Peck J, Slovek A, Miro P, et al. A Comprehensive Review of Viscosupplementation in Osteoarthritis of the Knee. Orthop Rev (Pavia). 2021;13(2):25549. Published 2021 Jul 10. doi:10.52965/001c.25549 

4)      Nguyen US, Zhang Y, Zhu Y, Niu J, Zhang B, Felson DT. Increasing prevalence of knee pain and symptomatic knee osteoarthritis: survey and cohort data. Ann Intern Med. 2011;155(11):725-732. doi:10.7326/0003-4819-155-11-201112060-00004