PRP Therapy for Knees | Use Your Own Platelets To Heal Your Knees

PRP Therapy For Knees


6-12 months after 3


Recovery Time
2 days mild swelling


Treatment Time
30 minutes


Estimated Price


Allurant Medical
by Dr. Kat Khorrami MD



PRP Therapy for Knees

PRP is a Platelet Rich Plasma injection into the knee to help with arthritis. It involves drawing a small amount of blood from the patient, running it through a centrifuge to promote levels of platelets in the blood which release healing growth factors, and then reinjecting it into the treated area which will cause a lot of healing in a short amount of time. This may be done in multiple sessions.

Cartilage worn down, known as osteoarthritis is the most common cause of arthritis in the knee. After cartilage wears away, the bone is exposed which leads to inflammation, swelling and pain.

Lifestyle changes are the best solutions for treating osteoarthritis, such as weight loss, exercise, and diet. Cortisone injections can cause harm and are limited in effects. Surgery is considered to be a last resort. PRP is a popular resort currently and is slowly becoming more popular.

Learn more about PRP injections for the knee below.

What is Defined as PRP?

PRP is platelet rich plasma, which is the patients blood that has been sent through a centrifuge to increase platelets which have growth factors. In other words, PRP is plasma with a high concentration of platelets which release growth factors when injected in a joint or tendon.

Ask Dr. Kat a Question:

Which PRP system is the best one?

PRP systems can differ with amount of platelets compared to whole blood in the sample, or possibly of white blood cells. The best solution depends on what you are treating. Some PRP systems concentrate platelets up to 8x the normal blood, others only 2x. Also, depending on spinning speed, white blood cell concentration can also be changed.
For knee arthritis we need up to 3x higher platelet concentration for the white cells. Higher concentration of blood platelets and higher concentration white cells are better for tendons. However studies are still needed for further investigation. Currently PRP is considered to be the best treatment for knee arthritis and there is also evidence that it can treat plantar fasciitis, tennis elbow, tendonitis in the rotator cuff and greater trochanteric syndrome.

Can I reverse damage in the joint with a PRP knee injection?

Yes, PRP can remove scarring tissue and heal injured tissue through growth factors in the plasma. Studies are still being done to see if PRP has a regenerative effect, however PRP growth factors do in fact change the tendon or joint environment for the better.

Would I need to set aside time to prepare for a PRP knee injection?

Yes you should follow the doctors advice for preparation before the procedure. We suggest you drink 1 to 1 and a half liters of water to be well hydrated on the day of PRP injection. Also, avoid medications that affect platelets i.e. ibuprofen or aspirin for 10 days pre injection, and you should also avoid these for a few weeks after getting the last injection.

How many injections of PRP do I need for arthritis of the knee?

For knee arthritis we recommend 2-3 injections about 2 weeks apart for best PRP therapy effects. Getting 2-3 injections done can last up to 24 months.

Is an injection guided by ultrasound the best option for knee PRP injections?

Yes this is the best way. With experienced hands, still only 80% of injections in the knee joint are made properly so 1 in 4 done without any imaging will miss the target. Guiding with x-ray or ultrasound will aid this completely and it is inexpensive also.

How long should I rest after getting PRP knee injections?

You should avoid exercising the joint for at least a week after the injection and this depends on what area is injected. If the structure or joint is weaker or has more problems, you may wish to increase rest time.

Side effects of knee PRP injections?

Side effects of PRP are rare but include risk of injection which is only .01% likely, pain flair, and rupture which is also very rare. Pain flair is typical and can sometimes last for a few weeks, so ice packs and paracetamol or codeine is recommended after injection. In 1-2% of cases, injections could actually worsen the problem. You should speak with your doctor regarding possible risks.

How long do positive effects last for?

Positive results can last for up to one year or possibly more. For the knee it can last for 12-18 months depending on the disease.

How expensive is a PRP knee injection?

We charge $800 per injection and we recommend a series of 3.

Can I combine hyaluronic acid with PRP?

Yes. Combining hyaluronic acid has shown to reduce pain and help treatment however, further studies are still pending.

Is a PRP knee injection better than using cortisone?

The positive effect is significant for 6 to 9 months for people with moderate arthritis. The effect is also double of the positive effects of cortisone. PRP is considered not harmful compared to cortisone which can sometimes damage cartilage.

Are stem cells considered better than PRP knee injections?

Stem cells are not known to be better than PRP knee injections. These cells can be proven to be better than PRP but there is little evidence to justify it over the expense. More evidence is needed to say it is better for knee arthritis than PRP.

Should I prepare for the PRP injection?

Yes, you must follow the doctors orders and drink 1-1.5 liters of fluid and avoid ibuprofen and aspirin 10 days before the procedure.

Can I get PRP done if I am using a blood thinner, one such as Warfarin?

Yes, there is no problem with blood thinners for PRP, however you should tell your doctor you are taking Warfarin as there is a higher risk of bleeding following the procedure.

Final words about Knee PRP injections

PRP can be used to treat many conditions including joint pain and is still becoming more popular with time. We are currently using low white cell based PRP therapy for arthritis in the knee combined with moderate exercise. We are reluctant for it to be used in other joints until there is more evidence.


Frequently Asked Questions

How long will Knee PRP injections last?

Studies show PRP injections may last up to 9 months.

Do these injections of PRP work in reducing knee pain?

Yes they do. Studies have shown it can improve low to moderate knee osteoarthritis and can significantly reduce pain also.

How many injections of PRP do I need for my knee?

You should need 2-3 injections about 2 weeks apart for best results, this can last up to 24 months.

What is the rate of success for injecting the knees with PRP?

This procedure has a high success rate, around 60%. This also depends on severity of the knee osteoarthritis.