Stem cell treatments for knee pain are available at orthopedic clinics, sports medicine centers, and regenerative medicine practices across the United States, but no standardized, FDA-approved stem cell injection for knee osteoarthritis exists yet. What you’ll find instead is a patchwork of clinics offering procedures that use your own cells, harvested from bone marrow or fat tissue, and injected into the knee. Understanding where these treatments are offered, what they actually involve, and what the evidence says will help you avoid overpaying for unproven claims.
Types of Facilities Offering Knee Stem Cell Treatments
Three main types of providers offer stem cell procedures for knees. The first is academic medical centers and large health systems. Northwell Health, for example, operates a Center for Regenerative Orthopedic Medicine with multiple ambulatory locations that offer orthobiologic treatments while tracking patient outcomes through registry systems and prospective studies. Mayo Clinic, Emory, and several other university-affiliated programs run similar clinics. These tend to be more transparent about what is and isn’t proven.
The second category is private orthopedic and sports medicine practices. Many orthopedic surgeons now offer regenerative injections as part of their practice, particularly in larger metro areas. These offices typically perform the harvest and injection in a single visit.
The third, and most common, is standalone regenerative medicine clinics. Hundreds of these operate nationwide, often advertising aggressively online. Quality varies enormously. Some are run by board-certified physicians following evidence-based protocols. Others make sweeping claims about regrowing cartilage that the science doesn’t support. A clinic’s willingness to discuss limitations honestly is one of the best signals of credibility.
What the FDA Actually Allows
The regulatory picture is important because many clinics market their treatments as “FDA approved” when they are not. The FDA regulates human cells and tissues under a framework called HCT/P rules. A clinic can use your own cells with minimal processing (like concentrating bone marrow) without needing drug approval, as long as the product is intended for “homologous use,” meaning the cells are being used for the same basic function they perform naturally. If a clinic goes beyond that, such as culturing or expanding cells in a lab, the product is regulated as a drug and requires formal FDA approval.
No stem cell injection product currently has full FDA approval for treating knee osteoarthritis. Some products made from amniotic tissue are still in clinical trials and are only available to patients enrolled as study subjects at approved trial sites. Surgical cartilage restoration procedures using your own cartilage cells or donor bone and cartilage grafts do have FDA approval and more than two decades of supporting data, but these are actual surgeries, not simple injections.
Two Main Approaches: Bone Marrow vs. Fat Tissue
Most clinics use one of two cell sources. Bone marrow aspirate concentrate (BMAC) involves drawing about 60 milliliters of bone marrow from your hip bone through a small incision, then spinning it in a centrifuge for about 15 minutes to concentrate the stem cells and growth factors down to roughly 8 milliliters. That concentrated sample is then injected into your knee. The hip is the preferred harvest site because it yields the highest concentration of useful cells.
The second approach uses fat tissue, typically harvested from your abdomen through small incisions after the area is numbed with a local anesthetic solution. The fat is mechanically processed to break it into tiny clusters, removing oil and debris, until it’s reduced to about 8 milliliters of microfragmented tissue for injection. Fat-derived cells are abundant, the harvest causes relatively little discomfort, and preclinical research suggests they may respond to inflammation in the joint somewhat better than bone marrow cells. A head-to-head clinical trial comparing the two approaches is currently underway, so definitive answers on which works better are still coming.
How Well It Works
A meta-analysis pooling data from multiple randomized controlled trials found that stem cell injections significantly reduced pain scores compared to control treatments at 3, 6, 12, and 24 months. The pain reduction was modest at 3 months but became more pronounced by 6 months, with that level of improvement holding steady through 12 months. At 24 months, patients in stem cell groups also showed better knee function scores than control groups.
That said, the picture isn’t entirely clear-cut. Improvements in stiffness and physical function didn’t consistently outperform control treatments at every time point. The strongest evidence is for pain relief rather than structural cartilage regrowth. Stem cell therapy appears to work best as a conservative treatment for osteoarthritis, reducing pain without the side effects associated with repeated cortisone injections or the recovery demands of surgery. It is not a cure, and results vary significantly from person to person.
Who Gets the Best Results
Candidates with mild to moderate osteoarthritis tend to respond better than those with severe, bone-on-bone degeneration. Most clinics will take an X-ray or MRI to grade the severity of your arthritis before recommending treatment. If your knee still has some cartilage left and reasonable joint alignment, you’re in the sweet spot. Patients with advanced arthritis, significant joint deformity, or inflammatory conditions like rheumatoid arthritis are generally less likely to benefit and may be better served by joint replacement.
Age, weight, and activity level also play a role. Younger, more active patients who can commit to post-procedure physical therapy and exercise routines tend to see stronger outcomes. The injection itself is only part of the equation; what you do afterward matters considerably.
What Recovery Looks Like
The procedure itself is typically done in a single office visit under local anesthesia. The harvest (from hip or abdomen) takes longer than the knee injection itself. Most people go home the same day.
In the first two to six weeks, you may notice gradual improvements in pain and mobility, though full function won’t be restored yet. The most significant gains typically show up between three and six months, as the injected cells work to reduce inflammation and support tissue repair. Many patients report continued improvement beyond six months, with benefits lasting a year or longer in some cases. Following prescribed physical therapy and activity modifications during this window is essential for the best outcome.
Cost and Insurance
This is where the picture gets uncomfortable. Most major insurance carriers do not cover stem cell injections for knees because the procedures are still considered investigational. Medicare does not cover them either. A small number of private self-directed insurance plans, some workers’ compensation cases, and certain military programs (particularly for elite units) will cover BMAC procedures, so it’s worth checking with your specific insurer.
Out-of-pocket costs typically range from $3,000 to $10,000 per knee, depending on the provider, geographic location, and which type of cell source is used. Some clinics charge significantly more. Academic medical centers don’t necessarily cost less than private clinics, but they’re more likely to be upfront about pricing and to track your outcomes systematically. If a clinic requires you to pay for multiple sessions upfront or pressures you with limited-time pricing, treat that as a red flag.
How to Evaluate a Clinic
Start by confirming the treating physician is board-certified in orthopedics, sports medicine, or physical medicine and rehabilitation. Ask whether they use image guidance (ultrasound or fluoroscopy) to place the injection precisely in the joint. Blind injections miss the joint space a surprising percentage of the time.
Ask what cell source they use and how it’s processed. If a clinic claims to offer “stem cell therapy” using amniotic fluid or umbilical cord products, be cautious. Many of these products contain few or no living stem cells, and the FDA has issued warnings about clinics marketing them misleadingly. Products derived from your own bone marrow or fat tissue, processed at the point of care without expansion or culturing, are on firmer regulatory ground.
Finally, ask about outcome tracking. Clinics that follow patients through registries or formal studies are invested in knowing whether their treatments work. Clinics that can’t tell you their own success rates may not be collecting that data at all.