Platelet-Rich Plasma Injections for Knee Pain: What Patients Should Know

What Is PRP and How Is It Prepared?

Platelet-rich plasma (PRP) is derived from your own blood. The process begins with a simple blood draw, typically 15 to 60 mL depending on the protocol. The blood is then placed in a centrifuge, which separates its components by density. The resulting platelet-rich layer is extracted and concentrated — producing a solution that contains platelets at levels several times higher than normal whole blood.

Platelets are best known for their role in clotting, but they also carry hundreds of growth factors and signaling proteins that regulate tissue repair and inflammation. When PRP is injected into an injured or arthritic joint, the concentrated growth factors are thought to stimulate local healing responses, modulate inflammatory signaling, and potentially support tissue regeneration.

PRP is an autologous treatment — it uses your own biological material — which means the risk of allergic reaction or rejection is essentially nonexistent. The preparation and injection process is typically completed within an hour in the office setting.

What Conditions Can PRP Address?

PRP has been investigated for a range of orthopedic applications. In the knee specifically, the conditions with the strongest current evidence include:

Knee osteoarthritis — Multiple randomized controlled trials have compared PRP to corticosteroid injections and hyaluronic acid injections for knee OA. The results generally show that PRP produces more sustained pain relief and functional improvement at 6 and 12 months, particularly in patients with early to moderate osteoarthritis.

Patellar tendinopathy — Chronic patellar tendon pain, common in jumping athletes, has shown positive responses to PRP injection in both clinical and ultrasound measures.

Partial ligament injuries — PRP is sometimes used to support healing in partial ligament tears, though the evidence here is less mature than for osteoarthritis.

It is important to understand that PRP is not a cure for osteoarthritis. It does not reverse cartilage loss or halt the underlying degenerative process. What it can do, in appropriate candidates, is meaningfully reduce pain and improve function — sometimes for 12 months or longer before repeat treatment is needed.

What to Expect from the Procedure

The injection is performed in the office. Depending on the location, ultrasound guidance may be used to confirm accurate placement. You may experience an increase in pain and swelling in the joint for several days after the injection — this is a normal inflammatory response associated with the biological activity of the growth factors. Most patients are advised to avoid strenuous activity for several days and to refrain from anti-inflammatory medications, which can blunt the intended healing response.

Clinical response to PRP is gradual. Unlike corticosteroids, which can provide relief within days, PRP effects typically build over four to eight weeks. If PRP is going to provide meaningful benefit, most patients experience it by the three-month mark.

Is PRP Covered by Insurance?

Most health insurance plans, including Medicare, currently classify PRP as investigational and do not cover it for musculoskeletal conditions. At Maryland Orthopedic Specialists, PRP injections are available as an out-of-pocket option — $500 for a single injection, or $750 for two injections performed on the same day. Your surgeon can help you determine whether PRP is likely to be a useful treatment given your diagnosis and the stage of your condition.

If you're experiencing knee pain and want to discuss your treatment options, the specialists at Maryland Orthopedic Specialists can help. Call (301) 515-0900 or [schedule an appointment online](https://www.mdorthospecialists.com/contact).