Platelet-Rich Plasma Injections for Knee Arthritis

by Christina Lasich, MD Health Professional

Like most people, you probably know someone that is struggling with a painful knee. Arthritis of the knee is common as a person ages, especially in those with previous injuries to the knee. At first one might try to use over-the-counter medications like ibuprofen or acetaminophen. Eventually, the pain becomes overwhelming and medical help is sought.

For a really inflamed knee, the doctor's first inclination is to inject it with steroids. The steroids help for a temporary period of time after which time a person returns to the doctor asking for another shot. Unfortunately, too many steroid shots cause damage. So, a doctor cannot inject the knee too many times without risk of further harm. In the past couple of decades, other types of injections have become available and are suitable alternatives to steroids without the nasty side effects.

The first alternative to steroid injections to become available was the synthetic hyaluronic acid (HA) injections, also known as viscosupplementation. By adding lubrication and cushioning to the joint, the viscosupplementation relieves pain; well that's the theory anyway. Over time, the limitations HA injections became apparent as people come limping back to the doctor's office within a matter of months. The benefits just don't last long.

With the demand for relief increasing, doctor's then discovered platelet-rich plasma (PRP) therapy for the treatment of orthopedic injuries. By injecting a joint with PRP, the growth factors and other rejuvenating properties found within the plasma provide a way to stimulate healing and regeneration. The adverse effects are minimal and the results are promising.

In a double-blind randomized control trial, people with knee osteoarthritis experienced continual improvement over a 12 month period of time after being injected a series of time with PRP compared with those injected with a saline placebo. 12 months of relief with minimal side effects is far superior to than the results found with intraarticular steroid injections or viscosupplementation. PRP injections perform best when a minimum of three injections are done with double-spinned plasma containing an activating agent that releases the growth factors. Of course, those with severe, end-stage knee osteoarthritis don't fare as well as those that have the injections done early in the disease process.

Knee osteoarthritis caught early enough can greatly benefit from minimally-invasive injection therapy with PRP. The potential benefits far outweigh the risks compared with both steroid and HA injections. Yes, there is added expensive but the long-lasting benefits make PRP treatment for knee osteoarthritis worthwhile based on the current medical evidence.


Arch Phys Med Rehabil. 2014 Mar;95(3):562-575

Arthroscopy. 2013 Dec;29(12):2037-48

Christina Lasich, MD
Meet Our Writer
Christina Lasich, MD

Christina Lasich, M.D., wrote about chronic pain and osteoarthritis for HealthCentral. She is physiatrist in Grass Valley, California. She specializes in pain management and spine rehabilitation.