What to Know About Knee Gel Injections (Viscosupplementation)

What are knee gel injections?

These injections contain hyaluronic acid (HA), a thick, gel-like substance. HA is naturally found in many parts of the body, including in the joints. It acts as a lubricant and helps keep tissues hydrated. These shots usually reduce pain and improve joint function.

What are some other names for these knee gel injections?

These injections may also be called “gel shots,” “viscosupplementation,” “visco shots, ”hyaluronic acid injections” or “HA injections.”

Some hyaluronic acid products are derived from rooster combs, which is why some people call these “rooster comb injections.” If you have an avian (bird) allergy, you should discuss this with your doctor.

How are gel shots different from cortisone shots?

Cortisone shots are another common treatment for knee osteoarthritis. These shots contain steroids that reduce swelling and irritation in the joint. They tend to work faster than HA injections, often within a few days. But the benefits are not as long lasting: Most patients start to feel pain again in 2 to 3 months.

Increasingly, patients with knee osteoarthritis are interested in learning about platelet-rich plasma (PRP) treatments as well. Some studies have suggested that PRP treatments help relieve joint pain and increase range of motion. They may last longer than both cortisone shots and HA injections. However, they are still considered experimental and are not covered by insurance.

What conditions do knee gel injections treat?

Patients with mild to moderate osteoarthritis best respond to knee gel injections. Those with more severe osteoarthritis, such as bone-on-bone knees, are less likely to benefit.

In some cases, HA injections may be used to treat osteoarthritis and misalignment in other joints, including the hip, shoulder, and ankle. These are considered "off label" uses and may not be covered by insurance.

Who is a good candidate for knee gel injections?

People with persistent knee osteoarthritis symptoms who have not responded to other treatments are the best candidates for hyaluronic acid injections. Before offering gel shots, doctors generally recommend that patients spend at least three months trying less invasive treatments, such as:

• physical therapy
• taking analgesic and anti-inflammatory medications like acetaminophen (Tylenol) and ibuprofen (Advil)
• modifying activities that seem to make symptoms worse

Those who do not get relief from these other interventions are often good candidates for HA injections.

Extra precautions are also needed for patients taking blood thinners. But just because you are on these medications doesn’t mean you can’t have HA injections.

How effective are knee gel infections?

For many patients, hyaluronic acid injections are very effective. They report feeling less pain and more mobility in their joints. One HSS study analyzing randomized controlled trials found these injections resulted in successful outcomes for 60.0% of knee osteoarthritis patients.

However, the researchers noted that these results may not accurately represent success rates in general, for example in a larger pool of patients. In a separate HSS study, HSS researchers found that HA injections helped patients delay the need for a total knee replacement and decrease the need for additional corticosteroid injections.

It is important to note that the effect from these shots is not immediate. It generally takes 4 to 6 weeks before you feel the full benefit from this procedure.

How long do the benefits from knee gel injections last?

The effect of the shots usually starts to wear off after about six months. If that happens, you can receive the treatment again.

How long does it take to get a knee gel injection? Is it painful?

Knee gel injections are done in the office and take just a few minutes. They may be performed using palpation guidance or ultrasound guidance.

Your doctor can numb the area with an anesthetic like lidocaine before giving the injection, to make the procedure more comfortable. Most patients describe the injections as uncomfortable but not extremely painful.

Patients with osteoarthritis in both knees can usually get them treated at the same appointment.

What is the recovery time for a knee gel injection?

Some patients say the area is sore and swollen for a few days afterwards, but others have no side effects at all. Icing the area for the first 24 to 48 hours after the treatment can help relieve these symptoms.

How soon can you return to exercise and other regular activities after having a knee gel injection?

It’s best for you to restrict strenuous activities for the first day or two after getting the shot. But after that, if you are feeling well, there are no restrictions.

What are the potential risks and side effects of knee gel injections?

The most common side effect is soreness or discomfort at the injection site. This goes away after a day or two.

In very rare cases, patients may experience something called a pseudoseptic reaction, where the area gets very red and swollen. It looks like an infection, but it is not. Rest and ice usually resolve the issue within one to two weeks. However, if patients are in the middle of receiving a series of injections, they need to discontinue their treatments.

Can you still have a knee replacement after a gel injection?

Patients’ disease often progresses, even after having success from HA shots. If your disease advances to the point where your doctor thinks you will benefit from knee replacement surgery, a history of receiving HA shots will not limit that option. However, surgeons generally recommend that you hold off on joint replacement until at least three months after your most recent knee injection.

What are the different types of knee gel shots?

There are several brands of hyaluronic acid injections. Some are given in a single shot and some are given over a course of either three or five treatments spaced one week apart.

Patients with busy schedules may prefer to be treated with a single shot so they don’t have to schedule multiple appointments. But treatments given over the course of three or five shots may be more effective because they can be given in slightly different parts of the knee.

Why might I get one brand of gel shot over another?

You and your doctor will determine which option is best, depending on your condition, any allergies you may have, and whether your insurance carrier prefers one formulation over another.

Synvisc (in three injections) or Synvisc-One (in a single injection) is one of the most common brands used. Other common options include Hyalgan (typically given as a series of weekly injections over five weeks) and Supartz FX (typically given as one injection a week over 3 to 5 weeks).

However, since these options are all derived from rooster combs, several alternatives are available for people who have bird allergies and/or for certain use cases. Non-animal-derived hyaluronic acid gel brands include Euflexxa, Durolane, Orthovisc, and Monovisc.

Does insurance cover knee gel injections?

Most insurance plans cover hyaluronic acid injections for symptomatic knee osteoarthritis not responding to other treatments. They often require that patients first try other treatments like physical therapy.

Some insurance plans may only cover certain brands of shots. The treatments that are given as a single shot tend to be more expensive and may not be covered.

What type of doctors provide knee gel injections?

Viscosupplementation treatments are most commonly given by physiatrists, sports medicine doctors, and orthopedic surgeons.

Why should I come to HSS for knee gel injections?

As an orthopedic specialty hospital, HSS has a great deal of experience in providing patients with hyaluronic acid shots as well as other therapies and procedures for osteoarthritis. Our high patient volume helps make the process smoother for patients. It also ensures that our doctors are on the cutting edge of new treatments.

Additionally, because HSS doctors offer a broad range of treatments for osteoarthritis, they are able to assess who is most likely to benefit from HA shots and who might do better with another treatment instead.

Posted: 11/26/2024

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References

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