PRP for Knee Arthritis: Who It Helps and What to Expect
PRP is a non-surgical option for knee arthritis that uses your own platelets, and the growth factors they release, in high concentration. I offer it to patients who want a more natural injection, who can’t take cortisone, or who want to delay surgery. Here’s how it works, when you’ll know if it’s working, how long it lasts, and how I talk about it when the arthritis is severe.
Key takeaways
- PRP uses your own platelets and the growth factors they release, in high concentration, to help heal and stabilize the cartilage you still have.
- It’s a non-surgical option that can help delay a knee replacement.
- We usually know if it’s starting to work by 4 to 6 weeks, and improvement can continue over months.
- Many patients get 6 to 12 months of relief. It can be repeated as early as 3 months.
- It’s a more natural option for patients who can’t take cortisone or don’t want it, and in some studies it lasts slightly longer than gel.
- With severe arthritis I usually recommend surgery, but no one is excluded. PRP is an option if you can’t have surgery or want to delay it.
If you have knee arthritis and want to stay away from surgery for now, platelet-rich plasma (PRP) is one of the options I offer. It's a non-surgical injection made from your own blood. Here's how I use it for the knee, and what I tell patients to expect.
What PRP is
PRP comes from your own blood. We draw a small sample, spin it to concentrate the platelets, and inject that concentrate into the knee. Platelets release growth factors. In high concentration, they can help heal and stabilize the cartilage you still have.
What PRP doesn’t do
PRP doesn't grow new cartilage or reverse arthritis. It works with the cartilage that's still there. See can you regrow knee cartilage?
Who can benefit
Any patient with knee arthritis can try PRP. The patients I most often talk to about it:
- Want a more natural option, made from their own blood
- Can’t take cortisone, or don’t want a steroid
- Have tried cortisone or gel and want something else
- Want to delay a knee replacement
- Can’t have surgery right now
How it's done
It's done in the office. We draw your blood, prepare the PRP, and inject it into the knee at the same visit. I recommend a course of two injections, two weeks apart. Some soreness for the first few days is normal.
When it works and how long it lasts
- We usually know if it’s starting to work by 4 to 6 weeks, and improvement can continue over months
- Many patients get 6 to 12 months of relief
- If it helps, it can be repeated as early as 3 months
How long it lasts depends on the patient. PRP isn't a quick fix the way cortisone is; it takes a few weeks before you feel it.
PRP vs. cortisone and gel for the knee
- Cortisone: works within days and is usually covered by insurance. It's a steroid, and some patients can't take it or don't want it.
- Gel (hyaluronic acid): a lubricating injection for the knee, covered by many plans.
- PRP: the more natural option, from your own blood. In some studies it lasts slightly longer than gel. It isn't covered by insurance.
Which one I recommend depends on the patient. For a side-by-side look, see injection options compared.
Severe or bone-on-bone arthritis
When the arthritis is severe and there are clear reasons for surgery, a knee replacement is usually my recommendation, and I'll tell you that. But no one is excluded from PRP. If you can't have surgery, or you want to delay it, PRP is an option and we can try it.
If you're wondering where your knee stands, see bone-on-bone knee: do you need surgery? and the signs you may need a knee replacement.
Is PRP covered by insurance?
No. PRP is considered elective and isn't covered by insurance. It is eligible for FSA and HSA funds. Cortisone and, in many cases, gel injections are typically covered.
Is PRP right for your knee?
That depends on your X-rays, how the knee is affecting your life, and what you want to do about it. I also offer PRP for the hip; the overview for both joints is PRP for hip and knee arthritis.
Frequently asked questions
Does PRP work for knee arthritis?
Yes, it can. PRP uses your own platelets and the growth factors they release, in high concentration, to help heal and stabilize the cartilage you still have. Many of my patients get 6 to 12 months of relief, and it can help delay surgery.
How long does PRP take to work in the knee?
We usually know if it’s starting to work by 4 to 6 weeks, and improvement can continue over months. It isn’t a quick fix like cortisone.
How long does a PRP knee injection last?
It depends on the patient, but many get 6 to 12 months of relief. If it helps, it can be repeated as early as 3 months.
Is PRP better than gel or cortisone for the knee?
They’re different tools. Cortisone works fast but is a steroid, and some patients can’t take it or don’t want it. PRP is more natural, since it comes from your own blood, and in some studies it lasts slightly longer than gel. Which one I recommend depends on the patient.
Does PRP work for a bone-on-bone knee?
When the arthritis is severe and there are clear reasons for surgery, a knee replacement is usually my recommendation, and I’ll tell you that. But no one is excluded. If you can’t have surgery or want to delay it, PRP is an option and we can try it.
Can PRP help me avoid a knee replacement?
It can help delay one. PRP doesn’t regrow cartilage or reverse arthritis, but by helping the cartilage you still have, it can keep you comfortable and active longer.
Is PRP for the knee covered by insurance?
No. PRP is considered elective and isn’t covered by insurance. It is eligible for FSA and HSA funds. Cortisone and, in many cases, gel injections are typically covered.
References
This article is for general education and is not a substitute for personalized medical advice. Please consult Matthew Harb, M.D. about the treatment options that are right for you.
What patients say
“Dr. Harb has kept my arthritic knee going for over a year and given me a high quality of life. When the time comes for replacement, I trust him.”
“He gives the best-placed cortisone shots — they help me get through the pain.”
“No pain with the cortisone shots is a major plus for me.”
Procedures & recovery
Signs You May Need a Knee Replacement
Most people with knee arthritis don’t need surgery any time soon — and surgery is rarely the first step. But it helps to recognize when arthritis is genuinely limiting your life, because with a knee replacement, you largely decide when it’s time. The decision is driven by your pain, function, and quality of life — not by an X-ray.
Read articleArthritis & Joint PainBone on Bone Arthritis: Do You Need Knee Replacement Surgery?
If you’ve been told you have “bone-on-bone” arthritis, the first question is usually whether you need a knee replacement. The answer may surprise you: not necessarily. A severe X-ray is only part of the picture — what matters far more is how the arthritis is affecting your life. We treat patients, not X-rays.
Read articleArthritis & Joint PainWhat Do You Have to Try Before a Joint Replacement?
Patients arrive convinced there is a fixed list of hoops to clear before anyone will operate. There is no universal medical requirement — but there are often insurance requirements, and those are a different thing entirely. Worth separating the two, because one is about your knee and the other is about a form.
Read articleWondering which treatment is right for you?
Schedule an evaluation with Dr. Harb to build an individualized plan — from nonsurgical care to replacement, when the time is right.
Not ready to book? Read how to choose a hip or knee surgeon