Bone Marrow Aspirate Concentrate (BMAC)
BMAC is a concentrate made from your own bone marrow, used as a non-steroid injection for knee and hip arthritis and to augment cartilage, rotator cuff, meniscus and hip surgery. Here is what it is, how it is done and what the research shows.
Request an AppointmentCall 469-850-0680All biologic treatmentsWhat is BMAC?
Bone marrow is the soft tissue inside bones. A small amount of marrow drawn from the pelvis contains a mix of cells, including a small population of progenitor (“stem”) cells, along with growth factors and other proteins that researchers are studying for their role in healing.1 The marrow is spun in a centrifuge to concentrate these components into bone marrow aspirate concentrate (BMAC), which is then injected into the arthritic joint or applied to a surgical repair.
BMAC is sometimes marketed elsewhere as a “stem cell injection.” That label can be misleading, because stem cells make up only a tiny fraction of the cells in BMAC, and how BMAC works is not fully understood. Dr. Dold prefers to describe it accurately as a concentrate of your own bone marrow. See stem cell injections: facts vs marketing.
1.How is BMAC different from PRP?
2.Is BMAC made from donor cells?
No. BMAC comes only from your own body. Dr. Dold does not offer donor “stem cell” products such as amniotic or umbilical cord injections.
BMAC for knee and hip arthritis
BMAC is used as a non-steroid injection for mild to moderate arthritis. Research findings include:
- A systematic review found that 34 of 36 patient-reported outcome measures (94.4%) improved significantly after BMAC injection for knee arthritis.5
- A 2024 review of 8 randomized trials (937 patients) found BMAC relieved pain and improved function, with better pain scores than gel injections at 6 and 12 months, although the differences were small.6
- In a randomized trial against gel injections, BMAC gave more durable results in mild arthritis, while gel results declined by 24 months.7
- In a 2025 study of 381 patients, BMAC had the highest responder rate of the injections studied, with about twice the odds of a meaningful response compared with a cortisone injection.8
- In a 15-year randomized study in which each patient received bone marrow concentrate in both knees, 20% of knees treated in the bone beneath the cartilage needed a knee replacement vs 70% of knees injected into the joint.9
The honest picture
In a placebo-controlled study where each patient had BMAC in one knee and saline in the other, pain improved similarly in both knees at 6 and 12 months, and MRI did not show cartilage regrowth.10,11 The AAOS technology review found that placebo-controlled studies did not show significantly better outcomes beyond 1 week and concluded that higher-quality research is needed,12 and reviewers note that the improvements are often modest and that a placebo effect cannot be ruled out.13 BMAC has also not been shown to be clearly better than PRP.5,3 Dr. Dold will review this evidence with you.
Like PRP, BMAC does not contain a steroid, so it avoids the concerns linked to repeated cortisone injections, such as cartilage loss and blood sugar rises in people with diabetes. See why consider a non-steroid injection.
3.Who is a candidate for a BMAC injection?
Usually people with mild to moderate knee or hip arthritis who want a non-steroid option and have not improved enough with exercise, weight management and medication. Results tend to be better in milder arthritis.7
4.How long does BMAC last?
In randomized trials, improvements after a single injection lasted at least 12 to 24 months on average,2,3,7 but results vary.
5.Does BMAC regrow cartilage?
Not as an injection alone. A placebo-controlled MRI study did not show cartilage regrowth after a single BMAC injection.11 The aim is to reduce pain and improve function.
6.How soon will I notice a difference?
In a randomized trial, patients improved by 1 month after the injection, with improvement reaching a plateau at about 3 months.2,3
7.Can BMAC be combined with PRP?
Yes. Some protocols combine bone marrow concentrate with platelet products; in one randomized trial, this combination gave better results than exercise therapy alone at 3 months, with improvements maintained to 2 years.14
8.Does BMAC work better in some patients than others?
Possibly. In a 2025 study, men, particularly those under 60, responded more favorably to BMAC, and a higher proportion of women than men responded to cortisone.8 Milder arthritis also tends to respond better.7
9.What is subchondral injection?
Some researchers inject bone marrow concentrate into the bone just beneath the damaged cartilage rather than into the joint. In a 15-year randomized study, this approach was linked to fewer knee replacements than joint injection.9 Dr. Dold will discuss whether this is appropriate for you.
10.BMAC or PRP: which should I choose?
Both are non-steroid options with similar results in a head-to-head randomized trial.2,3 PRP needs only a blood draw, while BMAC involves a bone marrow draw. Dr. Dold will help you choose based on your joint, your goals and your budget.
BMAC to augment surgery
The most compelling research on BMAC comes from its use during surgery, where it is applied directly to the repaired tissue. Dr. Dold may use BMAC as an adjunct during cartilage, meniscus, rotator cuff and hip procedures:
| Procedure | What the research shows when BMAC is added |
|---|---|
| Rotator cuff repair | In a case-controlled study of 90 patients, 100% of repairs augmented with bone marrow concentrate had healed at 6 months vs 67% without, and 87% vs 44% were still intact at 10 years.15 In a national database study, the 114 patients who received BMAC at the time of repair had a significantly lower rate of revision surgery at 2 years than 3,800 matched controls.16 |
| Cartilage repair | In a 5-year comparison, 100% of patients treated with a hyaluronic acid scaffold plus BMAC were rated normal or nearly normal at 2 years vs 64% after microfracture, and microfracture results declined to 28% at 5 years while the BMAC group maintained its improvement.17 A 14-year follow-up of the same technique reported lasting pain relief.18 Adding BMAC to microfracture with a realignment osteotomy improved cartilage repair quality in another study, although differences in clinical scores were small.19 |
| Hip arthroscopy | A 2025 systematic review of 252 hips found that adding BMAC to hip arthroscopy may improve patient-reported outcomes; three of the comparative studies favored BMAC.20 |
| Hip osteonecrosis (core decompression) | In a long-term randomized study, hips treated with core decompression plus bone marrow concentrate collapsed in 28% vs 72% with core decompression alone, and needed hip replacement in 24% vs 76%.21 It did not help hips that had already reached a later stage (stage 3).22 |
| Meniscus repair | A related technique, marrow venting, releases bone marrow into the knee during meniscus repair. In a randomized trial, 100% of vented repairs healed vs 76% without.23 |
11.Is BMAC harvested at the same time as surgery?
Yes. When BMAC is used during surgery, the marrow is typically drawn from the pelvis while you are under anesthesia and applied during the same procedure.
12.Will BMAC shorten my recovery after surgery?
BMAC may improve healing,15,17 but the repaired tissue still needs time to heal, so your rehab timeline is based on the surgery itself.
BMAC for tendon problems
Dr. Dold also uses BMAC for selected chronic tendon problems and partial tears that have not responded to physical therapy. Research on BMAC injections for tendons is more limited than for arthritis and surgical augmentation, and he will explain the evidence and alternatives, including PRP, before you decide.
Watch Dr. Dold: BMAC video
What to expect
- Numbing: the skin and bone surface over the back of the pelvis are numbed with local anesthetic.
- Bone marrow draw: a needle is used to draw a small amount of bone marrow, usually felt as pressure and a brief deep ache.
- Concentration: the marrow is spun in a centrifuge to make BMAC.
- Injection: the BMAC is injected into the joint or problem area in the same visit.
- Afterward: soreness at the pelvis and the injected joint for a few days is common. Dr. Dold will give you instructions for activity and pain relief.
13.Is the bone marrow draw painful?
Local anesthetic is used, and most patients describe pressure and a deep ache during the draw. Soreness at the site usually settles over a few days.
14.Is BMAC safe?
BMAC uses your own tissue, and very few complications have been reported with bone marrow harvesting.12 No serious adverse events were reported in several trials,10,7,14 and mild side effects were similar to gel injections.7
15.How many BMAC injections will I need?
Randomized trials have studied a single injection.2 Dr. Dold will discuss how many treatments make sense based on your response.
FDA status, cost and insurance
BMAC is not FDA-approved to treat any orthopedic condition. The FDA has warned patients that regenerative medicine products, including “stem cell” products, have not been approved to treat conditions such as osteoarthritis, tendonitis or joint pain, and that clinics marketing them as proven cures may be misleading patients.24 Dr. Dold presents BMAC as an evolving treatment, explains the evidence and its limits, and does not make promises about results.
16.Does insurance cover BMAC?
No. BMAC is not covered by insurance, so it is an out-of-pocket cost.12 Please call 469-850-0680 for current pricing.
17.How do I schedule a consultation?
- Board certified by the American Board of Orthopaedic Surgery, with subspecialty certification in Sports Medicine
- Sports medicine and arthroscopy fellowship at NYU Langone / Hospital for Joint Diseases; orthopedic residency at the University of Toronto
- Fellow of the American College of Surgeons (FACS), the American Academy of Orthopaedic Surgeons (FAAOS), the American Orthopaedic Association (FAOA) and the Royal College of Surgeons of Canada (FRCSC)
- Has cared for professional and Olympic athletes from the NFL, NBA, NHL, MLS, PGA Tour, Major League Rugby and USA Gymnastics
Research cited on this page
- Chahla J, Mannava S, Cinque ME, et al. Bone Marrow Aspirate Concentrate Harvesting and Processing Technique. Arthrosc Tech. 2017. PubMed
- Anz AW, Hubbard R, Rendos NK, et al. Bone Marrow Aspirate Concentrate Is Equivalent to Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis at 1 Year: A Prospective, Randomized Trial. Orthop J Sports Med. 2020. PubMed
- Anz AW, Plummer HA, Cohen A, et al. Bone Marrow Aspirate Concentrate Is Equivalent to Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis at 2 Years: A Prospective Randomized Trial. Am J Sports Med. 2022. PubMed
- Dulic O, Rasovic P, Lalic I, et al. Bone Marrow Aspirate Concentrate versus Platelet Rich Plasma or Hyaluronic Acid for the Treatment of Knee Osteoarthritis. Medicina (Kaunas). 2021. PubMed
- Keeling LE, Belk JW, Kraeutler MJ, et al. Bone Marrow Aspirate Concentrate for the Treatment of Knee Osteoarthritis: A Systematic Review. Am J Sports Med. 2022. PubMed
- Han JH, Jung M, Chung K, et al. Bone Marrow Aspirate Concentrate Injections for the Treatment of Knee Osteoarthritis: A Systematic Review of Randomized Controlled Trials. Orthop J Sports Med. 2024. PubMed
- Boffa A, Di Martino A, Andriolo L, et al. Bone marrow aspirate concentrate injections provide similar results versus viscosupplementation up to 24 months of follow-up in patients with symptomatic knee osteoarthritis. A randomized controlled trial. Knee Surg Sports Traumatol Arthrosc. 2022. PubMed
- Mautner K, Kaiser JM, Boggess B, et al. Autologous Cell Injections for Knee Osteoarthritis Display Greater Responsiveness Than Allogenic Cellular Products and Corticosteroids in a Sex-Dependent Manner. Am J Sports Med. 2025. PubMed
- Hernigou P, Bouthors C, Bastard C, et al. Subchondral bone or intra-articular injection of bone marrow concentrate mesenchymal stem cells in bilateral knee osteoarthritis: what better postpone knee arthroplasty at fifteen years? A randomized study. Int Orthop. 2021. PubMed
- Shapiro SA, Kazmerchak SE, Heckman MG, et al. A Prospective, Single-Blind, Placebo-Controlled Trial of Bone Marrow Aspirate Concentrate for Knee Osteoarthritis. Am J Sports Med. 2017. PubMed
- Shapiro SA, Arthurs JR, Heckman MG, et al. Quantitative T2 MRI Mapping and 12-Month Follow-up in a Randomized, Blinded, Placebo Controlled Trial of Bone Marrow Aspiration and Concentration for Osteoarthritis of the Knees. Cartilage. 2019. PubMed
- American Academy of Orthopaedic Surgeons. Concentrated Bone Marrow Aspirate for Knee Osteoarthritis: Technology Overview. 2021. Read the overview (PDF)
- Chahla J, Piuzzi NS, Mitchell JJ, et al. Intra-Articular Cellular Therapy for Osteoarthritis and Focal Cartilage Defects of the Knee: A Systematic Review of the Literature and Study Quality Analysis. J Bone Joint Surg Am. 2016. PubMed
- Centeno C, Sheinkop M, Dodson E, et al. A specific protocol of autologous bone marrow concentrate and platelet products versus exercise therapy for symptomatic knee osteoarthritis: a randomized controlled trial with 2 year follow-up. J Transl Med. 2018. PubMed
- Hernigou P, Flouzat Lachaniette CH, Delambre J, et al. Biologic augmentation of rotator cuff repair with mesenchymal stem cells during arthroscopy improves healing and prevents further tears: a case-controlled study. Int Orthop. 2014. PubMed
- Schoch BS, Werner BC, Shapiro SA, et al. Effect of Bone Marrow Aspirate Concentrate and Platelet-Rich Plasma Augmentation on the Rate of Revision Rotator Cuff Repair. Orthop J Sports Med. 2022. PubMed
- Gobbi A, Whyte GP. One-Stage Cartilage Repair Using a Hyaluronic Acid-Based Scaffold With Activated Bone Marrow-Derived Mesenchymal Stem Cells Compared With Microfracture: Five-Year Follow-up. Am J Sports Med. 2016. PubMed
- Whyte GP, Bizzoco L, Gobbi A. One-Step Cartilage Repair of Full-Thickness Knee Chondral Lesions Using a Hyaluronic Acid-Based Scaffold Embedded With Bone Marrow Aspirate Concentrate: Long-term Outcomes After Mean Follow-up Duration of 14 Years. Am J Sports Med. 2024. PubMed
- Cetin O, Durdi A, Beyzadeoglu T. Effect and comparison of bone marrow aspirate concentrate on cartilage regeneration and clinical outcomes following high tibial osteotomy and microfracture. J Orthop Surg Res. 2026. PubMed
- Lee MS, Pettinelli NJ, Gagné J, et al. Bone Marrow Aspirate Concentrate With Hip Arthroscopy in a Heterogenous Group of Patients May Result in Improved Patient-Reported Outcomes: A Systematic Review. HSS J. 2025. PubMed
- Hernigou P, Dubory A, Homma Y, et al. Cell therapy versus simultaneous contralateral decompression in symptomatic corticosteroid osteonecrosis: a thirty year follow-up prospective randomized study of one hundred and twenty five adult patients. Int Orthop. 2018. PubMed
- Hauzeur JP, De Maertelaer V, Baudoux E, et al. Inefficacy of autologous bone marrow concentrate in stage three osteonecrosis: a randomized controlled double-blind trial. Int Orthop. 2018. PubMed
- Kaminski R, Kulinski K, Kozar-Kaminska K, et al. Repair Augmentation of Unstable, Complete Vertical Meniscal Tears With Bone Marrow Venting Procedure: A Prospective, Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Study. Arthroscopy. 2019. PubMed
- US Food and Drug Administration. Important Patient and Consumer Information About Regenerative Medicine Therapies. 2021. FDA
Medically reviewed by Andrew P. Dold, MD, FAOA, FAAOS, FACS, FRCSC. Last reviewed October 2026. This page is general information, not medical advice. BMAC is not FDA-approved to treat any specific orthopedic condition, research is ongoing, results vary, and no outcome is guaranteed.
