PRP for Knee Osteoarthritis: Does It Work?

If knee osteoarthritis is making it hard to walk, climb stairs, or sleep, you may have heard about PRP — platelet-rich plasma. It’s a regenerative injection made from your own blood, and it’s become one of the most talked-about non-surgical options for arthritic knees. But does it actually work? At Empire Minimally Invasive Spine and Pain, our physicians offer PRP as part of a step-up plan for knee osteoarthritis across our New York and New Jersey offices. Here’s an honest look at what PRP can and can’t do for an arthritic knee.

What PRP is

Platelet-rich plasma is made from a small sample of your own blood. We spin it in a centrifuge to concentrate the platelets — the cells that release growth factors your body uses for healing. That concentrated plasma is then injected into the knee joint, usually with ultrasound guidance for accuracy. Because PRP comes from your own body, the risk of an allergic reaction is very low. You can read more about the full process on our PRP therapy page.

How PRP is thought to help an arthritic knee

Osteoarthritis isn’t only “wear and tear.” It also involves low-grade inflammation inside the joint that keeps the knee irritated and painful. The growth factors in PRP are believed to calm that inflammation and improve the joint environment. Rather than just numbing the pain the way some injections do, the goal of PRP is to change the biology inside the knee so it feels and functions better. Learn more about the condition itself on our knee osteoarthritis guide.

What the research actually shows

This is where honesty matters. Multiple randomized trials and reviews suggest that, for mild-to-moderate knee osteoarthritis, PRP can reduce pain and improve function — and several studies found its benefit lasted longer than hyaluronic acid (“gel”) injections or cortisone. That’s encouraging.

At the same time, the evidence is still mixed. PRP preparations are not standardized — the concentration and content differ from clinic to clinic and study to study — which makes results harder to compare. Some large trials have shown little difference from a placebo injection. Major medical organizations describe the evidence as promising but still evolving, and they have not universally endorsed PRP for knee OA. The reasonable takeaway: PRP helps some patients meaningfully, it is low-risk, but it is not a guaranteed fix and it is not a substitute for a full treatment plan.

Who tends to be a good candidate

• Mild-to-moderate knee osteoarthritis (rather than bone-on-bone, end-stage arthritis)
• Knee pain that hasn’t responded well to activity changes, physical therapy, or anti-inflammatory measures
• Patients who want to delay or avoid knee replacement and are willing to try a regenerative option
• People who prefer an injection made from their own blood over repeated steroid shots

Patients with severe, advanced arthritis often get less benefit from PRP. If that’s your situation, it’s worth reading whether a knee replacement is worth it so you can weigh your options honestly.

PRP compared with a cortisone shot

Both are injections, but they work differently. A cortisone (steroid) shot is a strong anti-inflammatory that often brings fast relief — but the relief can fade in weeks to a few months, and repeated steroid injections may not be ideal for the joint over time. PRP tends to work more gradually, over several weeks, but its benefit may last longer for the right candidate. Neither one reverses arthritis. Many patients ask which is better for them; the honest answer depends on your goals, your arthritis stage, and how you’ve responded to injections before.

What to expect from the procedure

PRP is an in-office procedure. We draw a small amount of your blood, prepare the plasma, and inject it into the knee, often using ultrasound guidance. The visit usually takes under an hour. Some patients feel soreness or fullness in the knee for a few days as the healing response begins — that’s expected. Because PRP relies on your body’s own repair process, improvement is gradual, and some patients need a short series of injections. Your physician will give you specific aftercare guidance based on your knee.

Frequently asked questions

Does PRP work for knee osteoarthritis?

For mild-to-moderate knee osteoarthritis, research suggests PRP can reduce pain and improve function for some patients, and its benefit may last longer than cortisone or gel injections. Results vary, and the evidence is still evolving. PRP tends to help less in advanced, bone-on-bone arthritis.

Does PRP regrow cartilage or cure arthritis?

No. PRP does not regrow lost cartilage or reverse osteoarthritis. Its goal is to calm inflammation and improve the joint environment so the knee feels and functions better. It’s a management tool, not a cure.

How long does PRP take to work?

PRP works gradually. Many patients begin to notice changes over several weeks as the healing response develops, rather than the fast relief a steroid shot can provide. Some patients need a short series of injections.

Is PRP covered by insurance?

PRP is often considered elective and may not be covered by insurance. Our team will explain the cost and your options before you decide. Call the office nearest you to ask about pricing and scheduling.

Is PRP safe?

Because PRP is made from your own blood, the risk of allergic reaction is very low. The most common side effects are temporary soreness or swelling at the injection site. Your physician will review any risks specific to you.