If knee arthritis is making everyday activities painful—walking, climbing stairs, or even getting out of a chair—you’ve probably looked for options that don’t involve surgery. One treatment many patients ask about is hyaluronic acid injections, also known as viscosupplementation.
So what are these injections, and do they actually work? Let’s take an evidence-based look.
Hyaluronic acid (HA) is a naturally occurring substance found in healthy joint fluid. Its main jobs are to lubricate the joint, absorb shock, and allow smooth, pain-free movement.
In knee osteoarthritis, the concentration and quality of hyaluronic acid decrease. The joint fluid becomes thinner and less effective, contributing to pain, stiffness, and inflammation.
Hyaluronic acid injections aim to restore the joint’s natural lubrication, improving function and reducing pain.
When injected directly into the knee joint, hyaluronic acid may help by improving joint lubrication and shock absorption, reducing inflammation inside the joint, decreasing bone-on-bone friction, and supporting healthier joint mechanics.
Unlike corticosteroid injections, which primarily reduce inflammation, HA injections are designed to improve the joint environment itself.
Clinical studies and large meta-analyses show that hyaluronic acid injections can provide meaningful pain relief for selected patients, particularly those with mild to moderate knee osteoarthritis.
Patients often experience modest but clinically meaningful pain improvement compared to placebo, along with better walking tolerance, reduced stiffness, and improved daily activity. Relief typically begins about 4–6 weeks after injection and may last 4–6 months or longer.
While steroid injections tend to work faster, hyaluronic acid often provides longer-lasting relief in patients who respond well. It’s important to note that results vary—some patients do very well, while others experience little benefit.
Hyaluronic acid injections tend to work best in patients who have early to moderate knee arthritis, remain active but are limited by pain, have not fully responded to physical therapy or medications, or are hoping to delay knee replacement surgery.
They are generally less effective in advanced, bone-on-bone arthritis where cartilage loss is severe.
Yes—hyaluronic acid injections have an excellent safety record. Side effects are usually mild and temporary, such as localized soreness or swelling. Serious complications are rare, and there is no risk of cartilage damage like there can be with repeated steroid injections.
Because hyaluronic acid closely resembles the body’s natural joint fluid, it is typically very well tolerated and can be repeated if effective.
Cortisone injections usually provide faster relief but tend to wear off within weeks. Hyaluronic acid takes longer to work but may offer benefits lasting several months. Repeated steroid injections may affect cartilage health, while HA is cartilage-friendly.
Cortisone is often used for acute inflammation, while hyaluronic acid is better suited for ongoing arthritis management.
They don’t reverse arthritis—but for many patients, they can reduce pain enough to stay active, improve quality of life, and delay the need for knee replacement surgery.
For those not ready—or not ideal candidates—for surgery, this can be a valuable option.
Hyaluronic acid injections are a safe, evidence-supported treatment option for many patients with knee osteoarthritis. While they don’t work for everyone, the right patient can experience meaningful pain relief, improved function, and longer-lasting benefits than some other non-surgical treatments.
If knee pain is limiting your life, a personalized evaluation with an orthopedic specialist can help determine whether hyaluronic acid injections are right for you—or whether another treatment would be more effective.
Conservative care always comes first, and the best treatment is the one tailored to your specific knee, goals, and lifestyle.
