The short answer
Bone marrow aspirate concentrate (BMAC) concentrates the cells and growth factors from a sample of your own bone marrow and delivers them under image guidance to a damaged joint or tendon. It is an advanced orthobiologic option for select patients with arthritis or tendon injury seeking a natural, non-surgical alternative.
Medically reviewed by Marc Gruner, DO, MBA, RMSK
Sports medicine physician, Mayo Clinic fellowship. Last reviewed June 2026
Adipose & Bone Marrow Orthobiologic Treatments — Dr. Marc Gruner
How it works
BMAC draws a small sample of bone marrow — typically from the pelvis under local anesthesia — and concentrates the reparative cells and growth factors it contains. Under ultrasound or fluoroscopic guidance, the concentrate is delivered precisely to the target joint or tendon.
Dr. Gruner considers BMAC for select patients with osteoarthritis or certain tendon and ligament injuries, often when other measures haven't provided lasting relief. Candidacy and realistic expectations are reviewed individually; certain blood conditions are contraindications.
Why patients choose it
- Uses your own bone marrow cells
- Image-guided delivery to the target
- Outpatient, non-surgical procedure
- An option for select moderate joint and tendon problems
How to prepare for your procedure
Following these steps gives your treatment the best chance to work. If anything here conflicts with another physician’s instructions, call the office before changing anything.
- 1.
Stop anti-inflammatories 2 weeks before — and 4 weeks after
Stop NSAIDs such as ibuprofen, naproxen, and similar anti-inflammatories two weeks before your procedure and for four weeks afterward. Orthobiologics work by triggering your body's own healing response, and anti-inflammatories blunt exactly that process. Do not stop prescribed aspirin, blood thinners, or any other prescription medication without checking with Dr. Gruner or the prescribing physician first.
- 2.
Have physical therapy scheduled
Make sure physical therapy is lined up before your procedure — rehabilitation is what converts the biology into lasting function. If you have Medicare, we'll get you set up on a remote monitoring platform so your progress is tracked between visits.
- 3.
Complete your outcome measures beforehand
You'll receive short outcome-measure surveys by email before your visit. Please complete them ahead of time — they establish your baseline so we can objectively measure how much you improve.
- 4.
Arrive 1 hour before your procedure
Plan to arrive a full hour ahead. That gives us time to check you in, complete the preparation, draw and process your sample, and get you positioned without anything feeling rushed.
- 5.
Bring athletic attire
Bring workout clothes. You'll spend a short time exercising on a bike before your blood draw — this mobilizes your platelets so we can collect the highest concentration possible for your treatment.
What to expect at your visit
- 1.
A focused conversation
Dr. Gruner reviews your history, prior imaging, and goals — what you want to get back to doing.
- 2.
Point-of-care ultrasound
When useful, a diagnostic musculoskeletal ultrasound evaluates the injury in real time, with no radiation.
- 3.
A clear, individualized plan
You leave understanding the diagnosis, the non-surgical options, and the expected timeline — in plain language.
Before and after your procedure
- How should I prepare for a BMAC procedure?
- Hold NSAIDs and, when advised, blood thinners in advance, hydrate, and eat beforehand. Because bone marrow is drawn (usually from the pelvis) under local anesthesia, arrange a ride home. Dr. Gruner confirms candidacy and pre-procedure steps first.
- What is aftercare like following BMAC?
- Expect soreness at the harvest site and the treated area for a few days. Avoid anti-inflammatory medications for several weeks, rest and modify activity briefly, and follow the return-to-activity timeline Dr. Gruner provides. Improvement develops gradually.
Rehabilitation protocol by body area
What to expect week by week after your procedure. Your plan is individualized; follow these alongside your physical therapist.
Knee & Hip Joint — Ultrasound-Guided PRP / Adipose / BMAC Injection Protocol
Day 1–2
Protect the joint
- Weight-bear as tolerated; crutches as needed
- Keep bandage dry; no submerging for 72 hours
- Gentle ROM as tolerated; monitor wound
Day 3–7
Begin gentle loading
- Avoid excessive joint loading
- Start low-grade closed-chain program
- Light squats/lunges (bodyweight); optional BFR
Day 8–14
Add resistance
- Avoid impact and heavy lifting to the joint
- Light open-chain exercises; add resistance as tolerated
- May begin swimming and low-resistance biking
Day 14–28
Functional progression
- Avoid impact activities
- Progress functional program; light agility and proprioception
- Resume light aerobic activity (walking)
Beyond 28 days
Long-term prevention
- Establish a long-term home exercise program
- Correct biomechanical issues that contributed to the injury
Do not use NSAIDs (ibuprofen, Aleve, aspirin) for 4 weeks, and avoid ice for the first week — both blunt the healing response. Acetaminophen (Tylenol) is fine for discomfort. Care is tailored to you; use these guidelines with your physical therapist.
Frequently asked questions
- Am I a candidate for BMAC?
- Candidacy depends on your diagnosis, severity, prior treatments, and overall health. A history of certain blood diseases (such as lymphoma or leukemia) is a contraindication. Dr. Gruner evaluates this individually.