Can Bone Marrow Concentrate Help Knee Pain? One Patient’s 3-Month Knee Osteoarthritis
Updated: Oct 24
What Is Bone Marrow Concentrate for Knee Pain—and Why Treat the Bone?
By Deborah Westergaard, MD
Regen Experts | Dallas & Plano, Texas
His knee pain could reach 7 or 8 out of 10.
Three months later, what was he reporting?
One of my patients recently returned for his three-month follow-up after treatment of his right knee.
Before treatment, he described episodes of increased knee pain reaching approximately 7–8 out of 10. How much he hurt depended partly on how physically active he had been, and some flares could last a day or longer.
At three months, his answer was quite different.
He reported that his usual pain was zero.
And when I asked what happened when he increased his activity enough to aggravate the knee?
“Two or three, if that.”
Those are his results. They are not a prediction of what another patient will experience.
But his story illustrates something I think is important about treating knee osteoarthritis:
Sometimes we need to look beneath the cartilage.
Bone Marrow Concentrate for Knee Pain: Why I Look Beyond the Cartilage
When patients hear “knee osteoarthritis,” they often think of worn cartilage.
Cartilage certainly matters. But osteoarthritis is not simply a disease of cartilage.
The knee functions as a biological and mechanical system. Depending on the patient, the clinical picture may involve articular cartilage, the subchondral bone immediately beneath it, the meniscus, synovium, ligaments, tendons and other structures surrounding the joint.
The cartilage and underlying subchondral bone are sometimes described together as the osteochondral unit because changes in one can affect the other.
That matters clinically.
Two people can both have “knee osteoarthritis” written on an MRI report and have very different symptoms, mechanical problems, bone findings, instability and treatment options.
That is why I do not treat an MRI diagnosis.
I treat the patient who brought me the MRI.
I want to know where the knee hurts, what provokes the symptoms, how the knee functions, what the physical examination shows and whether those findings actually correlate with the imaging.
What Did We Treat in This Patient?
“Intraosseous” simply means within the bone.
That is different from performing only an intra-articular injection, where the biologic is placed inside the knee joint.
Why would I consider treating the bone?
Because immediately beneath the articular cartilage is the subchondral bone. In some patients with knee osteoarthritis, MRI demonstrates abnormalities in this region, including bone-marrow lesions.
The presence of an MRI abnormality does not automatically mean that it should be injected. Imaging still has to make sense in the context of the patient's symptoms, examination, alignment, stability and overall clinical picture.
But the concept of treating the subchondral bone is not simply theoretical.
There are human clinical data behind it.
What Does the Evidence Say About Intraosseous Bone Marrow Concentrate for Knee Osteoarthritis?
This is where the literature becomes particularly interesting.
Much of the published research on bone marrow aspirate concentrate, or BMAC, for knee osteoarthritis has evaluated injections placed inside the knee joint.
That is useful information, but it is not exactly the same procedure this patient received.
There is also a body of research specifically examining the subchondral bone.
The Hernigou 15-Year Randomized Study
One of the studies I find particularly relevant was performed by Philippe Hernigou and colleagues.
The investigators studied 60 patients with painful bilateral knee osteoarthritis. Because each patient had osteoarthritis in both knees, the researchers were able to use the patient's opposite knee as a comparison.
Bone marrow concentrate was prepared during the same anesthetic.
One knee was randomized to receive the preparation in the subchondral bone of the femur and tibia.
The other knee received the same dose intra-articularly, inside the joint.
This is an unusually interesting study design because many of the variables that make comparisons between different patients difficult were reduced: the two knees belonged to the same person and had similar grades of osteoarthritis.
At two years, the investigators reported greater clinical and MRI improvement in the knees treated in the subchondral bone.
They then continued following the patients.
At an average of 15 years, 12 of the 60 knees treated in the subchondral bone had undergone total knee arthroplasty.
In comparison, 42 of the 60 knees treated with the intra-articular injection had undergone total knee arthroplasty.
That was 20% versus 70% in this particular study population.
That does not mean that an intraosseous BMC procedure will prevent a knee replacement in an individual patient.
It does, however, make the subchondral bone difficult to dismiss as an irrelevant treatment target.
Another Long-Term Hernigou Study
Hernigou and colleagues also studied 140 older adults with bilateral medial-compartment knee osteoarthritis who had been planning staged bilateral knee replacements.
During the same anesthetic, one knee underwent total knee arthroplasty while the contralateral knee received bone-marrow-derived cell treatment in subchondral lesions of the femur and tibia.
The patients were followed for an average of approximately 15 years.
Twenty-five of the 140 biologically treated knees ultimately underwent total knee arthroplasty, with those replacements occurring at an average of approximately 10 years after treatment.
The researchers also found that persistence of larger bone-marrow lesions was associated with subsequent arthroplasty.
Again, this does not prove that today's intraosseous BMC procedure will postpone knee replacement for a particular patient.
But it provides long-term human evidence supporting something I think is clinically important:
The bone beneath the cartilage may matter.
What Does More Recent Research Show?
Research has continued to examine this concept.
A 2026 systematic review evaluated 24 studies involving 1,109 patients receiving different types of subchondral knee injections. Eight of those studies involved mesenchymal-cell-based approaches, and five of the 24 studies were randomized controlled trials.
Most studies reported improvements in pain and function. The review noted that the cell-based studies had the most favorable long-term findings, including reports extending to 15 years.
But there is an important limitation: overall study quality was modest, protocols varied considerably, and the authors called for better standardized, high-quality randomized trials.
That is an appropriate conclusion.
Promising evidence is not the same thing as settled science.
A separate 2026 retrospective study evaluated fluoroscopically guided subchondral BMAC in patients with knee osteoarthritis and MRI-confirmed femoral or tibial bone-marrow lesions. Investigators reported improvement in clinical outcomes as well as changes in MRI bone-marrow-lesion severity.
Because that study was retrospective rather than randomized, I view it as supportive evidence rather than definitive proof.
And What About BMC Injected Only Into the Joint?
The broader intra-articular BMAC literature also deserves consideration.
A systematic review of eight randomized studies involving 937 patients found significant improvements from baseline in pain and function following BMAC treatment.
In comparisons with hyaluronic acid, BMAC produced statistically favorable pain results at some follow-up points, but the differences did not exceed the minimal clinically important difference. Comparisons with other injection therapies likewise did not establish clear clinical superiority.
That finding does not negate the BMAC results.
It tells us something different.
Patients receiving intra-articular BMAC improved, but current randomized evidence has not consistently demonstrated that an intra-articular BMAC injection is dramatically superior to every other injection treatment.
And that brings us back to the question raised by the Hernigou research:
In selected patients, does targeting the subchondral bone matter?
The long-term data suggest that it may.
We still need better trials to determine which patients benefit most, which imaging findings are most important, and which treatment protocols produce the most reproducible outcomes.
What I Do Not Tell Patients
I do not tell a patient that bone marrow concentrate will “grow a new knee.”
I do not promise that it will regenerate normal cartilage.
And I do not promise that it will prevent knee replacement.
Those claims go beyond what current clinical evidence can support.
What I can tell a patient is that there is a scientific rationale for evaluating the entire osteochondral unit, that human clinical research has reported improvements following BMC treatment, and that long-term randomized data have produced particularly interesting findings when the subchondral femur and tibia were treated.
That is a very different statement from promising regeneration.
His Numbers Tell a Story But Only His Story
Now come back to my patient.
Before treatment, he reported pain exacerbations of approximately 7–8/10.
At his three-month follow-up, he reported that his usual pain was 0/10.
When increased activity caused a flare, he described it as approximately 2–3/10 — “if that.”
I am very pleased with what he is reporting.
But a patient testimonial is not a randomized clinical trial.
His improvement cannot establish that BMC was solely responsible for every change he experienced, and his response cannot tell us what another patient's response will be.
It tells us what happened to this patient during the first three months after treatment.
And that is worth reporting honestly.
Who Might Consider Bone Marrow Concentrate for Knee Pain?
The question I want a patient to ask is not simply:
“Do I have arthritis?”
I would rather answer more useful questions.
What structures appear to be contributing to the pain?
Is there clinically relevant subchondral bone involvement?
Are there bone-marrow lesions?
What does the meniscus look like?
Is the knee stable?
What is the alignment?
Are tendons or ligaments contributing?
How advanced is the osteoarthritis?
Do the physical examination and imaging tell the same story?
And perhaps most importantly:
What does this person want to be able to do again?
For someone whose knee pain is interfering with walking, exercise, travel, work or other activities that matter, an orthobiologic evaluation may be reasonable when that person wants to understand nonsurgical options before making a major treatment decision.
That does not mean everyone with knee arthritis should receive PRP, BMC or an intraosseous procedure.
Sometimes conservative treatment makes the most sense.
Sometimes an orthobiologic procedure may be reasonable.
And sometimes the degree of arthritis, deformity, instability or another structural problem means that a surgical consultation is the appropriate next step.
The point of a careful evaluation is not to find a procedure for every patient.
It is to determine which option makes sense for this particular knee.
Three Months Is Encouraging. It Is Not 15 Years.
The Hernigou studies are valuable partly because they remind us why long-term follow-up matters.
My patient is three months out.
That is an encouraging early result. It is not a declaration of permanent success.
We will continue to follow his symptoms and, just as importantly, his function.
For now, however, his answer is meaningful.
Before treatment, his knee pain could reach a 7 or 8 out of 10.
Three months later, he tells me his usual pain is zero.
And when he pushes the knee enough to aggravate it?
“Two or three, if that.”
That is his experience.
And sometimes what a patient can comfortably return to doing tells me at least as much as another number on an MRI report.
Frequently Asked Questions
Can bone marrow concentrate help knee pain?
Clinical studies have reported improvements in pain and function in some patients with knee osteoarthritis following bone marrow aspirate concentrate treatment. Randomized and observational studies have also investigated placing bone-marrow-derived preparations into the subchondral bone. Results are encouraging, but individual responses vary and the evidence does not establish that every patient will benefit.
What is intraosseous bone marrow concentrate treatment of the knee?
“Intraosseous” means within bone. In selected patients, bone marrow concentrate may be placed into specific areas of subchondral bone in the femur or tibia rather than treating only the inside of the knee joint. The rationale is based on recognition that osteoarthritis can involve the osteochondral unit, including the bone immediately beneath the cartilage.
Is there long-term research on subchondral bone marrow treatment?
Yes. Hernigou and colleagues published randomized studies with approximately 15 years of average follow-up. In one paired-knee study involving 60 patients, 20% of knees receiving subchondral treatment underwent knee replacement compared with 70% of contralateral knees receiving the same preparation intra-articularly. These findings are important but should not be interpreted as a guarantee that treatment will delay or prevent arthroplasty in another patient.
Why would the femur and tibia be treated for knee osteoarthritis?
The ends of the femur and tibia contain the subchondral bone immediately beneath the joint cartilage. Osteoarthritis can involve this bone as well as cartilage and other joint structures. MRI may demonstrate bone-marrow lesions in some patients. Whether these findings are clinically relevant requires correlation with symptoms, physical examination and the rest of the imaging.
Does bone marrow concentrate regrow knee cartilage?
It should not be assumed that BMC will restore normal cartilage. Research continues into the biological effects of bone marrow concentrate, but current clinical evidence does not justify promising cartilage regeneration to an individual patient.
Is bone marrow concentrate a “stem-cell injection”?
That description can be misleading. Bone marrow concentrate is an autologous preparation made from a patient's own bone marrow and contains multiple cellular and signaling components. Some research studies characterize or quantify mesenchymal stromal/stem-cell populations within bone marrow preparations, but describing the entire clinical product simply as a “stem-cell injection” can overstate what is being administered.
Can bone marrow concentrate prevent knee replacement?
No physician can responsibly promise that. Some long-term studies of subchondral bone-marrow-derived treatment have reported delayed or lower subsequent arthroplasty rates in the populations studied, but those findings cannot predict whether an individual patient will ultimately require knee replacement.
How long does it take to know whether knee BMC treatment helped?
Response and recovery vary. Three months can provide useful early information about pain and function, but it does not establish durability. Longer-term follow-up is important.
Who is a candidate for knee orthobiologic treatment?
Candidacy depends on more than having “arthritis.” Symptoms, physical examination, imaging, subchondral bone findings, arthritis severity, alignment, stability, medical history, previous treatment, activity demands and personal goals can all influence whether PRP, BMC, intraosseous treatment or another approach is reasonable.
Considering Your Options Before Knee Surgery?
If knee pain is limiting the activities that matter to you, the first question does not necessarily have to be:
“Which procedure should I get?”
A better starting point may be:
What, exactly, is causing my knee pain — and what options make sense for my particular knee?
At Regen Experts, I evaluate the knee as a whole before recommending treatment.
Deborah Westergaard, MD
Regen Experts
Dallas & Plano, Texas
Individual results vary. This patient's testimonial describes his individual experience and does not predict another patient's outcome. Orthobiologic procedures are not appropriate for every patient and cannot be guaranteed to regenerate cartilage, prevent progression of osteoarthritis or avoid knee replacement. Treatment recommendations require an individualized medical evaluation.
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