There are more non-surgical options than ever to help reduce pain (even heal?) your knees. The information gathered below is from reviewing available research – I am not an MD, but having had a lifetime of knee pain (born with a rare congenital condition), I like to share what I’ve learned about latest in medicine with you so you can make more informed decisions about your own knee care.
I’d LOVE to hear about your own experience with any of these injections. Please leave comments below!
I’m primarily talking about reducing pain of knee osteoarthritis (OA), but other forms of knee pain may well be helped by these methods.
If you’ve had enough non-steroidal anti-inflammatory medications, such as ibuprofen (eg Advil), acetaminophen (eg Tylenol), and naproxen sodium (eg Aleve), what else can you do …before advancing to surgery?
INJECTIONS! There are four main injection therapies available today: Corticosteroids, Hyaluronic Acid, Platlet-Rich Plasma, and Stem Cells.
I’m not condoning any one of these (because YOU need to find what is right for you), but I have had Cortisone, Hyaluronic Acid, and PRP injections all working to reduce pain at some level for a few months.
Here are the basics so you can go to your doctor to ask more informed questions…
Injections commonly called “Cortisone”, injection administered 1 time.
Corticosteroids help reduce inflammation through a complex action. They interrupt the inflammatory response at several levels which help reduce pain and may increase joint mobility and viscosity of joint fluid. A cortisone shot usually includes corticosteroid medication and local anesthetic.  
A corticosteroid shot is commonly used as the first treatment for knee OA.
Why you want it: Corticosteroid shots can give you temporary reduction in pain while your body heals (but they don’t fix the cause of the pain).
Risks: Post-injection flare in 2-25% within a few hours of injection that may last 2 to 3 days. Are multiple cortisone shots for knee OA bad? The risk of cartilage loss after multiple injections is very low (0.7%-3.0%) .
Injection compounds called “Synvisc” or “Orthovisc” administered 1 – 3 times over several weeks.
It is called Viscosupplementation because the injection enhances the viscosity (thickness) of your synovial fluid. Hyaluronic Acid (HA) is a naturally occurring component of synovial fluid (remember synovial fluid is like your joint oil). Viscosupplementation’s role in synovial fluid is to enhance viscosity to act as a lubricant during slow joint movements and as an elastic shock absorber during rapid joint movement. It also helps to reduce stress and friction on cartilage and may provide an anti-inflammatory benefit. These injections are often covered by insurance.
Do they work? The scientific jury is out on the effectiveness of HA shots  with some studies showing benefit and others showing the same effect as a placebo. Many insurance programs no longer cover the $250-$750 HA injections.
Risks: Low rate of adverse reaction (2% – 4%), low probability of infection. (2).
PRP is created from your own blood draw on the day of your injection appointment. Methods vary from one single injection to 3 injections over 3 weeks.
Platelet Rich Plasma is prepared from the patient’s own blood which is spun in a centrifuge to obtain a highly concentrated sample of platelets. The platelet solution is used to create a platelet gel rich in growth factors and bioactive molecules which act to reduce pain, inflammation, and improve function. PRP may help stimulate production of healthier joint fluid and may slow progression of OA .
PRP is a relatively new generation of bioactive treatments and is not yet widely used. There are multiple options for PRP injections that have differing concentrations for platelets, white blood cells, and growth factors. The ideal balance has not yet been determined .
Does PRP work? Studies show relief from pain for up to 12 months.
PRP injections are not yet FDA approved and not typically covered by insurance. PRP shots can cost $500-$1200 per injection.
Risks: low risk with transient pain and localized swelling.
Stem cell applications vary from a one time visit to multi-day applications.
Stem cell injections are a promising bioactive technology and least widely used of the injections listed here. Mesenchymal stem cells, obtained from the patient’s bone marrow or fat cells, have the potential to differentiate into any kind of cell, including cartilage and bone tissues. The premise is that stem cell application, both through injection or surgical implantation, may offer possible regenerative mechanisms to repair or possibly regenerate cartilage (2014) and relieve pain.
There is much research and application of stem cells with specialty clinics popping up everywhere. Stem cells are definitely the big hope. But what does science say? Again, the scientific jury is still out. There are studies that show significant improvement for patients with low-grade OA to studies that show no difference between stem cell and placebo control groups. There is still uncertainty to best source of stem cell (adipose tissue, bone marrow, embryonic tissue), method of application, number of injections, size of injection, and long-term efficacy.
Is stem cell for you? You’ll need $3,000-$15,000 of your own money to try stem cells for your knee. It is less expensive than knee replacement and may (or may not) solve your problems. Be sure to research the sources of stem cell and the application method proposed by your doctor.
Risks: Adverse reactions with pain and swelling (3.1%) and theoritcal risk of being carcinogenic (not yet proved.) 
 Mayo Clinic (2013) Cortisone Shots. Rretrieved 9/8/15 from http://www.mayoclinic.org/tests-procedures/cortisone-shots/basics/definition/prc-20014455.
 Arthroscopy: The Journal of Arthroscopic and Related Surgery (May 2018). Injections for Knee Osteoarthritis: Corticosteroids, Viscosupplementation, Platelet-Rich Plasma, and Autologous Stem Cells. David M. Levey, MD., et al.
 Pak, J., Lee, JH., Lee SH. (2014) Regenerative Repair of Damaged Meniscus with Autologous Adipose Tissue-Derived Stem Cells. US National Library of Medicine, National Institutes of Health. Retrieved on 9/8/15 from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3925627/
 Centeno C, Pitts J, Al-Sayegh H, Freeman M. Efficacy of autologous bone marrow concentrate for knee osteoarthritis with and without adipose graft. Biomed Res Int 2014;2014:370621.