About Bone Marrow Aspirate Concentrate (BMAC)
Bone marrow contains a mix of cells and signaling proteins that take part in the body's normal repair processes. BMAC collects a small amount of marrow and concentrates it so it can be placed precisely into an injured area. Everything comes from your own body, and it is prepared and injected during a single appointment.
We consider BMAC for joint arthritis and for some chronic tendon problems, often when a person has already tried rehab and other injections, or when the problem is more extensive than PRP is typically used for. In arthritis, BMAC does not rebuild cartilage, but it may reduce pain and help you move better. In tendons, it can support healing of small partial tears.
Dr. Gruner and Dr. Chen perform both the marrow draw and the injection themselves, using ultrasound for each step. BMAC is combined with a progressive rehab plan so the tissue is gradually loaded as it settles.
Where we use BMAC
Watch: BMAC explained
What happens during treatment
- 1.
Your physician confirms the diagnosis with an exam, ultrasound, and any needed imaging, and reviews whether BMAC fits your goals.
- 2.
You lie face down, and the skin and bone surface over the back of the pelvis are numbed with local anesthetic.
- 3.
Using ultrasound guidance, your physician draws a small amount of bone marrow through a needle.
- 4.
The marrow is processed in a centrifuge to create a concentrate while you rest.
- 5.
The skin over the target is numbed, and the concentrate is injected under live ultrasound into the joint or tendon.
Who may be a good candidate
- Adults with knee, hip, shoulder, or ankle arthritis who have not had enough relief from exercise, weight management, and simpler injections.
- People with chronic tendon problems or small partial tendon tears who have not improved with rehab or PRP.
- Patients who want to stay active and are not ready for, or not candidates for, surgery.
- People who are comfortable with a same-day procedure under local anesthetic.
Recovery
The pelvis where marrow was drawn is usually sore and bruised for several days, and the treated joint or tendon is often sore too. Most people rest the area for a short time, then begin gentle movement and a structured loading plan. Improvement, when it happens, typically builds over several weeks to months. We follow you closely and adjust rehab as you progress.
Risks and limits
Common effects are soreness at both the marrow draw site and the injection site. Less common risks include infection, bleeding or bruising, and nerve irritation. We usually pause anti-inflammatory medicines around the procedure, and blood thinners need careful review beforehand. BMAC is not appropriate for people with active infection, certain blood disorders, or active cancer. It does not rebuild cartilage, it cannot repair a complete tendon tear, and results vary from person to person.
What to expect at your visit
- 1.
We listen first
Your visit opens with a real conversation: how the problem started, what you have already tried, and the activity you want back.
- 2.
Exam and in-office ultrasound
A hands-on exam, then ultrasound at the exam table, often while you move, so your physician can see the tendon, joint, or nerve involved.
- 3.
A clear diagnosis and plan
You leave knowing what is wrong and what your options are, from strength-based rehab to procedures, and why we recommend each one.
- 4.
Treatment and follow-through
Most procedures happen here in the office. We coordinate with your physical therapist and check progress against the goals you set.
Rehab protocols
Dr. Gruner's week-by-week recovery guidelines. Your plan is individualized; follow these with your physician and physical therapist.
Questions about BMAC
- Does the bone marrow draw hurt?
- The skin and the surface of the bone are numbed first. Most people feel pressure and a brief pulling sensation during the draw rather than sharp pain. The area is usually sore for a few days afterward.
- How is BMAC different from PRP?
- PRP comes from your blood and concentrates platelets. BMAC comes from your bone marrow and contains a broader mix of cells and signaling proteins. We may suggest BMAC for more advanced joint problems or when PRP has not helped enough.
- Will BMAC reverse the arthritis in my knee?
- No. BMAC does not rebuild worn cartilage. Its goal is to reduce pain and improve function so you can stay active and keep strengthening the muscles that protect the joint.