Knee pain is one of the most common complaints among adults, affecting 25% of people in the US. As we age, the likelihood of experiencing knee pain also increases. For those living with knee osteoarthritis, the stiffness, swelling, and aching can impact everything from walking, running, or going up and down stairs. In recent years, platelet-rich plasma (PRP) injections have been gaining attention as a possible treatment option for osteoarthritis (OA). You might be asking, “what exactly is PRP for knee osteoarthritis?” Does it really work? Is it right for me? This post will review what PRP for knee osteoarthritis is, look at the science behind it, discuss the current research, and let you know what to consider before considering this type of treatment.
**This is not medical advice. Please consult your medical provider for more information.
What Is PRP and How Does It Work?
Platelet-rich plasma (PRP) is an injection made into the knee. First, a small sample of blood is taken. It is placed in a centrifuge to separate the platelets from the other components of the blood. The platelets contain growth factors. Growth factors are natural proteins that play a major role in tissue repair. This concentrated solution of plasma is then injected into the specific area requiring treatment. For knee osteoarthritis, it gets injected into the knee joint.
PRP is injected into the knee joint to stimulate the body’s own healing response. The theory behind it is that the growth factors will improve lubrication of the joint, reduce inflammation, and could even promote tissue repair. As this is a new and upcoming form a therapy, the exact mechanism is still being studied. The ultimate goal is to provide relief to the joint due to OA.
Why PRP Is Being Used for Knee Osteoarthritis
To understand why PRP is being used to treat OA, we first have to understand what osteoarthritis is. Osteoarthritis is when the cartilage within your joints gradually wears down. The cartilage provides a low-friction surface so your bones glide smoothly over one another. This “wearing away” of the cartilage is part of the normal aging process. It is possible to have OA in multiple joints throughout the body. It’s also possible to only have it in just one joint. A prior history of significant injuries to certain joints can increase the likelihood of developing OA in the future.
PRP for knee osteoarthritis has been proposed as an alternative or complementary treatment because it uses your own biology to try to reduce symptoms. Unlike medications, which often treat pain but not the underlying tissue environment, PRP is designed to improve the overall condition of the joint. PRP is often used in conjunction with other conservative treatments, including physical therapy. In fact, I have had multiple patients come to me for knee OA who have also received PRP injections. While it does not work for everything, it can provide significant relief for some. Some individuals even report full resolution of symptoms.
Potential Benefits of PRP Therapy
While the research out there is mixed regarding PRP for knee osteoarthritis, there are specific benefits that we do know exist. Individuals who have responded well to PRP have experienced a reduction in their knee pain and an improvement in both joint function and joint mobility. This improvement can lead to the possibility of delaying knee replacement surgery. For some, this may have even led to not needing knee replacement surgery at all! This is more common for those who have had more mild knee osteoarthritis. On occasion, there are fewer side effects compared to medications or steroids, since PRP as a treatment uses your own blood.
For many, the appeal in trying PRP for knee osteoarthritis comes down to a natural, minimally invasive option before moving to surgical interventions. PRP paired with physical therapy can help boost the potential benefits after PRP. Physical therapy aims to restore knee joint mobility, function, and strength with exercise. paired with the potential benefits of PRP, this can be a great option for many trying to delay knee replacement surgery.
Other Posts Related to Knee Osteoarthritis and Knee Replacement Surgery
- Osteoarthritis Treatment for the Knee: What You Need to Know
- Physical Therapy Exercises for Knee Pain: How to Reduce Arthritic Pain
- 4 Mistakes You Don’t Want to Make After Knee Replacement Surgery
- What is the Recovery Time for Knee Replacement?
Limitations and Considerations to Keep in Mind
PRP therapy is not a one-size-fits-all approach. Nor is it a guaranteed solution. Outcomes vary widely. These outcomes are related to your prior medical history, comorbidities, severity of osteoarthritis, current level of activity in your lifestyle, and your history and response with other therapies. It also comes down to how your body reacts to it. Some people see significant relief. others notice very little to no change. You can be a good candidate on paper, and sometimes, it still doesn’t work. Keeping that in mind, you won’t know unless you try.
Another challenge with PRP is the lack of standardization. Difference clinics prepare PRP differently, which may potentially affect results. And while side effects are rare, there is always the possibility of temporary pain, swelling, or irritation at the injection site. Not to mention, most insurance providers don’t cover PRP. Cost can be an important factor when considering PRP. Most patients are left to pay out-of-pocket for this type of treatment.
What the Research Says About PRP for Knee Osteoarthritis
Research on PRP has grown significantly in the past decade. Studies show that some patients with mild to moderate knee osteoarthritis report reduced pain and improved function after PRP injections. In some cases, PRP has been shown to perform better than corticosteroid or hyaluronic acid injections, especially in the months following treatment.
That said, the evidence is mixed. Not all studies show clear benefits. Much depends on how the PRP is prepared, how many injections are given, and the severity of the osteoarthritis. Based off of this meta-analysis, the current level of evidence is quite low and clinical trials show a high level of bias. Future research will still be needed for long-term effects >12 months, as this is an area that is still significantly lacking.
Always remember to do your own research. Weigh the pros and cons. Discuss this with your doctor to determine if this is a good course of action for you. This is more than just a therapy due to the fact of having knee OA. You also have to take into consideration your history, severity of OA, other comorbidities, and response to other therapies. Last but not least, always remember that there is a possibility PRP therapy might not work for you, even if you are determined to be a good candidate.
Who Might Be a Good Candidate?
PRP may be most effective for individuals dealing with mild to moderate osteoarthritis. This is especially true for those looking to delay surgery or explore other conservative treatments before considering surgery as an option. In cases of severe knee OA, PRP might not be enough to see a noticeable differences in symptoms or function, as the joint damage is often too significant.
To be a good candidate, your osteoarthritis has to be contributing pain and affecting your ability to perform daily tasks, such as walking, going up and down stairs, playing with your grandkids, and performing household chores. Some people may find out that they have osteoarthritis, but have no symptoms, including no pain. Just because you have arthritis doesn’t mean there is automatically pain. But in order to be a candidate for PRP, the arthritis must be negatively impacting your life and how you function. There’s no reason to consider a treatment when there are no symptoms.
PRP may also be effective for those who haven’t responded to traditional therapies. Other therapies include physical therapy, acupuncture, or corticosteroid injections. It could also provide some relief for individuals who cannot take NSAIDs for pain relief.
It is important to note that there is no universally adopted list of criteria to determine who may be a good candidate for PRP related to knee osteoarthritis. However, this list is a good starting point that can help you determine if this may be an option. Speak with your doctor to fully determine if you may be a good candidate.
Complementary Approaches That Support PRP Outcomes
Although PRP can be a treatment option when physical therapy has failed as a conservative treatment, physical therapy can also be a complementary therapy that supports PRP outcomes. PRP for knee osteoarthritis may work best when paired with lifestyle and therapeutic strategies that support joint health.
Osteoarthritis responds really well to exercise, making physical therapy a strong viable option for most cases. Movement and exercise brings fluid to the joint space to help lubricate the joint. Incorporating physical therapy for OA and tailored exercises into your routine can play a transformative role in symptoms management. Pair this with PRP and the outcomes from both therapies can drastically improve function and reduce pain.
PRP can also be used as a way to better participate in physical therapy. For some people, it can be challenging to participate due to the amount of pain they have in their knee with physical activity. There are some instances when physical therapy is not the best fit. However, there have been instances when these individuals go back to their doctor, receive PRP, and then their pain levels diminish. They are then sent back to physical therapy to continue to work on improving strength, mobility, and function of the knee joint.
A physical therapist can guide you in exercises that strengthen the muscles around your joints, reducing the burden on them and easing any remaining pain. Whether it’s through enhancing flexibility, building strength, or improving balance, these interventions are key to managing osteoarthritis. Not only do they help in mitigating discomfort, but they also empower you with more control over your wellbeing, making daily activities more manageable.
Other Factors to Consider
While physical therapy is one of the best options for treating knee osteoarthritis, there are some other factors to consider that can play a role in pain management. Many have to do with lifestyle.
While weight is not the reason you may have pain in your knee with osteoarthritis, it could play a factor. When standing, your knees bear 1.5x your weight. This increases to 2-3x your body weight when walking and up to 5-6x with squatting. Standing, walking, and squatting are all activities we perform on a daily basis. If weight is of concern, this can add a significant amount of pressure on your knees. Your muscles of the knee (and the rest of your body) then have to have the strength to be able to support this amount of pressure. While the strength of your muscles is more important than your actual weight, weight management may be something your doctor speaks to you about for pain management or for preparing for surgery.
Another thing to consider is that stress and pain are closely linked. Have you ever noticed on days where you are significantly more stressed than others, are your pain levels higher? If stress and tension commonly accompany your days, you might want to consider mindfulness or breathwork practices. Mindfulness can make pain easier to manage as pain is a sensation generated within your brain. Working on mindfulness can reduce those pain signals from the brain to various areas of your body. Nervous system work can also address these concerns.
References
Costa LAV, Lenza M, Irrgang JJ, Fu FH, Ferretti M. How Does Platelet-Rich Plasma Compare Clinically to Other Therapies in the Treatment of Knee Osteoarthritis? A Systematic Review and Meta-analysis. Am J Sports Med. 2023 Mar;51(4):1074-1086. doi: 10.1177/03635465211062243. Epub 2022 Mar 22. PMID: 35316112.
Emily Mende, Ryan J Love, Jody-Lynn Young, A Comprehensive Summary of the Meta-Analyses and Systematic Reviews on Platelet-Rich Plasma Therapies for Knee Osteoarthritis, Military Medicine, Volume 189, Issue 11-12, November/December 2024, Pages e2347–e2356, https://doi.org/10.1093/milmed/usae022
TL;DR
PRP for knee osteoarthritis is a treatment where platelets from your own blood are injected into the knee to reduce pain and improve function. Research suggests it may help some people, especially those with mild to moderate osteoarthritis, though results vary. If you’re considering PRP, pair it with proven approaches like physical therapy and lifestyle shifts for the best chance of relief. This post reviews what PRP for knee osteoarthritis is, looks at the science behind it, discusses the current research, and informs you on what to consider before considering this type of treatment.
Tera Sandona is a licensed Doctor of Physical Therapy (DPT) and the founder of PT Complete. She helps high-achieving women break out of cycles of chronic pain, stress, and burnout through her Regulate and Rebuild Method, a sequenced approach that addresses the nervous system first and builds strength second. Her work focuses on helping women finally understand their bodies, rebuild strength, and create lasting resilience that fits real life.
