Does PRP Work for Knee Osteoarthritis? What the Evidence Shows

What is PRP Therapy?

PRP stands for Platelet-Rich Plasma. It is prepared from a small sample of the patient's own blood, which is processed in a centrifuge to concentrate the platelets and growth factors. This concentrated preparation is then injected into the affected joint. Because it is derived entirely from the patient's own blood, the risk of adverse reaction is extremely low. Learn more about our PRP therapy protocol.

What Does the Clinical Evidence Show?

PRP for knee osteoarthritis has been studied in multiple randomised controlled trials and systematic reviews. The overall picture from the research is broadly positive, particularly for mild to moderate osteoarthritis.

A systematic review published in the American Journal of Sports Medicine found that PRP injections produced significantly greater improvements in pain and function compared with hyaluronic acid injections at 6 and 12 months. Multiple studies comparing PRP with cortisone show that while cortisone provides faster short-term relief, PRP consistently produces better outcomes at the 6 and 12 month marks.

The mechanism is well understood: PRP delivers concentrated growth factors directly into the joint, which modulate the inflammatory environment and support the body's natural repair processes. This is fundamentally different from cortisone, which suppresses inflammation temporarily but does not address the underlying degenerative process.

Who is Most Likely to Benefit?

The evidence is strongest for patients with mild to moderate knee osteoarthritis. Patients with more advanced joint degeneration may still benefit, though the response is more variable. PRP is also well established for knee tendon conditions, ligament injuries and post-surgical recovery support. See our full guide to knee osteoarthritis treatment.

PRP is less likely to produce significant results in end-stage osteoarthritis where there is almost complete cartilage loss. In these cases, a more advanced orthobiologic protocol or surgical consultation may be more appropriate.

How Does PRP Compare to Knee Replacement?

PRP is not a replacement for knee replacement surgery in patients who genuinely need it. However, for many patients who are considering knee replacement, particularly those in their 50s and 60s with moderate osteoarthritis, PRP and other orthobiologic treatments offer a meaningful non-surgical alternative worth exploring before committing to an irreversible procedure.

At CellOrtho Marbella, we regularly treat patients who have been told knee replacement is their next step. For a significant proportion of these patients, a course of orthobiologic treatment provides enough pain relief and functional improvement to delay or avoid surgery altogether. Book a free video consultation to discuss your case.

What to Expect from PRP Treatment for Knee Pain

A typical PRP protocol for knee osteoarthritis involves 1 to 3 sessions, spaced 4 to 6 weeks apart. Most patients notice gradual improvement from 4 to 6 weeks after the first session, with continued progress over 3 to 6 months as the biological repair processes take effect. The procedure itself takes approximately 45 to 60 minutes including preparation.