Worth a Shot: How Helpful are Knee Injections for Arthritis Pain?

Nauman Akhtar, MD, is board-certified in orthopaedic surgery. He specializes in arthritis and joint replacement and serves as medical director of the Inova Loudoun Hospital Joint Replacement Program.

Knee pain from arthritis can take a major toll, limiting your ability to do the things you love. But few people are eager to undergo knee replacement surgery.

Many of my patients ask about injections as an alternative to treat their knee pain. These can be a big help, but it’s important to understand the pros and cons.

Cortisone Shots

Cortisone shots are the traditional go-to injections for joint pain. They can be used in most joints affected by arthritis, including the knee, ankle and elbow.

Cortisone shots work by reducing inflammation caused by arthritis. They can be quite effective at reducing pain, but it’s a short-term fix. Relief typically lasts up to a couple of months, and sometimes only several weeks. However, some newer time-release varieties are becoming available, which can help extend the relief.

Cortisone shots can only be given every four months. And each time you get an injection, it tends to be less effective. Still, many people find the shots relieve their pain, and they are often covered by insurance.

Gel Shots: Hyaluronic Acid Injections

Hyaluronic acid injections are nicknamed “gel shots.” Hyaluronic acid works like WD-40 for the joint, lubricating it to help it move smoothly. That smooth movement can reduce inflammation and ease pain. There are a few different varieties on the market, but with all of them you can expect to receive 1 to 5 shots over several weeks.

Unfortunately, the results of gel shots are hard to predict. Some people have great outcomes, with pain relief that lasts for months. In other people, though, we don’t see much improvement at all. Still, hyaluronic acid injections are approved for treating the knee joint, and are often covered by insurance.

PRP Injections

Platelet-rich plasma (PRP) is an injection made from the patient’s own blood cells. After blood is drawn, the sample is spun down to concentrate the platelets — a component of blood that contains growth factors important for healing. Then the PRP is injected back into the patient’s joint.

PRP has gained popularity in recent years, with pro athletes touting its effectiveness for treating injuries such as tendonitis. But its use for arthritis is still controversial. Researchers are testing PRP for arthritis of the knee, but we don’t know yet how effective it is. Since PRP is still experimental, it’s not typically covered by insurance.

Stem Cell Injections

Stem cells are immature cells that can develop into many different types of tissue in the body. In recent years, stem cell injections have become popular as a treatment for all sorts of ailments, including osteoarthritis. The cells are typically isolated from a patient’s own blood or bone marrow, then injected into the achy joint.

Some people have reported significant pain relief after stem cell treatment. But the science is limited, and their use is controversial. Like platelet-rich plasma, stem cell injections are pricey and rarely covered by insurance.

When to Consider Knee Injections

If you’re dealing with persistent arthritis pain, we usually recommend starting with conservative treatment: ice, rest, bracing and physical therapy. If that doesn’t help, an injection is often worth a try.

It’s important to remember it’s not a long-term fix. Still, injections can delay the need for knee surgery. And sometimes, injections provide enough pain relief to allow you to be more active and participate in physical therapy — which can help improve your pain and range of motion over time.

Injections are very safe, with the main risk being a very small chance of infection. Though results can be hit-or-miss, one way to increase the likelihood of success is to make sure the shot lands in the right spot. At Inova, we often use ultrasound guidance to make sure we’re placing the injection precisely in the joint.

Whether you’re thinking about knee replacement or hoping to find relief through shots, we can help. Learn more about the Inova Loudoun Hospital Joint Replacement Program.


  1. dan on August 20, 2019 at 4:21 pm

    Well written and informative. I guess not much has changed in the last 30 years- yes I know PRP and stems are new but as with most new therapies likely to be of little benefit.

  2. Mimi on August 25, 2019 at 10:49 am

    I have had “gel shots” in my right knee four times over a space of 8 years. Three shots each time. They worked very well, but each time for a shorter period of time. I was able to postpone knee replacement until the age of 78. I wish there were “gel shots” for the shoulder.

  3. Jack on August 27, 2019 at 9:18 am

    I agree, well written and informative. Articles on other subject matters would be appreciated. Examples would be on the specific types of cancers and the treatments used for each. An article on gene therapy, gene editing, and perhaps targeted immune therapy.

    Thank you for giving me the opportunity to comment.

  4. Lyla on September 3, 2019 at 1:02 pm

    It’s interesting how stem cells from your own bone marrow or blood can be used to improve conditions like arthritis. I have arthritis in my right knee from an injury a few years ago, and it prevents me from doing things I used to really enjoy, like hiking. I will definitely look further into stem cell treatments to see if it can help me.

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