Joint Injections for Knee Arthritis
Overview
Living with knee pain can make even simple things—like walking the grocery aisles, climbing stairs, or playing with family—feel challenging. This guide explains the most common joint injections used to relieve arthritis pain, reduce inflammation, and help you move more comfortably.
(This information is for education only and should not replace professional medical advice.)
1. Understanding Your Knee Pain
What Is Osteoarthritis?
Knee osteoarthritis happens when the smooth cartilage that cushions the bones in your joint wears down over time. Without this natural cushion, the bones rub together, which can cause pain, swelling, and stiffness.
Although cartilage loss can’t be reversed, the symptoms it causes can be managed effectively. Joint injections are one of the key non-surgical ways to reduce pain and inflammation right at the source—helping you stay active and enjoy life again.
2. The Goal of Joint Injections
Managing Symptoms—Not a Cure
The purpose of a joint injection is to calm pain and inflammation so you can move better. These treatments don’t rebuild cartilage or “cure” arthritis, but they can significantly improve comfort and mobility.
Think of an injection as a temporary relief tool. It helps manage flare-ups, makes movement easier, and sometimes postpones or avoids surgery—like a knee replacement—altogether.
3. Exploring Your Treatment Options
Four Common Injection Types
Below is an overview of the four most common injection options, how they work, what the evidence says, and key considerations for each.
💉 Cortisone (Steroid) Injections – Fast, Reliable Relief
What it is: A mixture of a powerful anti-inflammatory steroid (such as triamcinolone) and a local numbing medication.
How it works: The numbing medicine provides quick pain relief for several hours. The steroid begins working within a few days, reducing inflammation for weeks or sometimes months.
What the evidence says: Research—including the AAOS Clinical Practice Guideline (2021)—shows that cortisone injections provide effective short-term pain relief for knee osteoarthritis. The benefit is typically up to a few months, and injections are best used to calm a flare or help regain mobility.
Key points:
Can help confirm that the knee joint is the source of pain.
Temporary “steroid flare” (brief soreness) can occur.
For patients considering knee replacement, it’s best to avoid surgery for at least 3 months after a cortisone shot to lower infection risk.
Generally covered by insurance.
💧 Hyaluronic Acid (HA) Injections – The “Lubricant” Option
What it is: A gel-like substance that adds lubrication and cushioning to the joint (“gel shots”).
How it works: Supplements the knee’s natural fluid to help the joint move more smoothly.
What the evidence says: Research shows limited benefit for most patients. The AAOS does not recommend routine use of HA injections since large studies have not found consistent improvement.
Key points:
Usually covered by insurance.
Low risk overall, but a rare allergic-type reaction can occur.
May still be an option for patients who prefer to try non-steroid approaches.
🩸 Platelet-Rich Plasma (PRP) – Your Body’s Own Healing Factors
What it is: A sample of your own blood is processed to separate the platelets and growth factors, which are then injected back into the knee.
How it works: These growth factors may reduce inflammation and promote local tissue healing.
What the evidence says: Some studies show PRP can help with pain and function in mild-to-moderate arthritis for 6–12 months, but results vary. It does not regrow cartilage.
Key points:
Results depend on how the PRP is prepared.
Generally safe, but not covered by insurance.
Primary drawback is cost.
🧬 “Stem Cell” Injections – Hope vs. Reality
What it is: A procedure using cells taken from your own fat tissue or bone marrow, injected into the knee.
How it works: Despite the name, these treatments do not contain true stem cells that rebuild cartilage. Their potential benefit comes from “signaling factors” that may help reduce inflammation—similar to PRP.
What the evidence says: Current research does not support stem-cell injections as an effective arthritis treatment. They are not FDA-approved and remain experimental.
Key points:
Not covered by insurance.
Very expensive (thousands of dollars).
Be cautious of clinics claiming miracle “stem-cell cures.”
4. At-A-Glance: Comparing Your Injection Options
Primary Goal
What the Evidence Shows
Coverage / Cost
Cortisone (Steroid)
Quick pain and inflammation relief
Moderate evidence for short-term benefit (weeks to months)
✅ Usually covered
Hyaluronic Acid (HA)
Add lubrication and cushioning
Weak evidence; not routinely recommended by AAOS
✅ Usually covered
Platelet-Rich Plasma (PRP)
Use body’s growth factors to calm inflammation
Mixed evidence; may help mild cases for 6–12 months
💰 Not covered
“Stem Cells”
Reduce inflammation via signaling
No proven benefit; not FDA-approved
💰💰 Very high cost
5. Frequently Asked Questions
Q: Do the injections hurt?
Most injections include a numbing medicine. You might feel brief pressure or a sting, but most patients find the procedure tolerable.
Q: How long before I feel relief?
If a numbing medicine is used, you may feel quick relief for a few hours. The main medication (like cortisone) takes several days to reduce inflammation fully.
Q: How many cortisone shots can I get per year?
Most doctors recommend no more than 3–4 injections per year in the same joint. They’re best used for flare-ups, not on a regular schedule.
Q: What are signs of infection after an injection?
Call your doctor immediately if you notice increasing redness, warmth, swelling, or pain several days after the injection—or if you develop fever or feel unwell. Though rare, infection is the most serious complication.
6. Key Takeaways
Injections manage symptoms, not the disease. They reduce pain and inflammation but do not rebuild cartilage.
Evidence varies. Cortisone is the most proven option; HA, PRP, and “stem cell” treatments show mixed or limited results.
A personalized approach is best. The right choice depends on your arthritis severity, activity level, and goals.
Partnership matters. Your orthopedic specialist can help tailor treatment for your lifestyle and long-term health.
If you live in or near Galesburg, Illinois, and knee pain is limiting your life, we’re here to help.
Disclaimer
This information is for educational purposes only and should not replace professional medical advice. Always consult your orthopedic specialist for individualized care.
