STEM CELL & BONE MARROW THERAPIES

01 / Understand

What is it?

“Stem cell therapy” is an umbrella marketing term, not a single orthopedic treatment. Autologous procedures use material from the patient's own body; other products may use donor tissue. These products are not interchangeable.

Bone marrow aspirate concentrate (BMAC) is processed bone marrow containing a mixture of cells and other components. It is not a purified dose of stem cells. Same-day preparation differs from laboratory expansion, which grows cells over time.

02 / Understand

How is it supposed to work?

Proposed mechanisms include biological signaling that may affect inflammation or tissue repair. Laboratory plausibility is not the same as a demonstrated clinical benefit.

Image guidance can help a clinician position a needle, but it does not prove where cells remain afterward, how long they survive or whether an ACL regains a functional attachment.

03 / Understand

Can stem cells help a torn ACL heal?

The science is more complicated than the marketing. The ACL connects the femur and tibia and helps limit forward movement and rotation. Its attachment to bone matters as much as the appearance of the tissue between those attachment points.

Partial and complete tears differ. Location, remaining fibers, retraction, associated meniscus injuries and clinical laxity can affect treatment decisions. A smaller gap alone is not a validated promise of success.

A 2015 uncontrolled case series reported changes after autologous bone marrow-derived injections. Without a comparator, it cannot establish that the injections caused those changes. A 2025 randomized crossover study evaluated bone marrow concentrate plus platelet products against exercise in selected non-retracted tears without meniscus injuries. Its selected sample, crossover design and combined treatment limit generalization and do not isolate a stem-cell effect.

Neither improved MRI appearance nor patient-reported function alone establishes a stable ligament attachment, safe return to rugby or reduced reinjury. Evidence does not justify a blanket claim that cell treatments regenerate or reattach torn ACLs.

Conventional alternatives include structured rehabilitation and, for selected patients, surgical repair or reconstruction. Discuss anatomy, instability, meniscus damage and activity goals with an appropriately qualified clinician.

04 / Understand

What outcomes matter?

Pain, function, structural healing, mechanical stability, return to sport, reinjury and long-term outcomes are different measures. Feeling better does not necessarily mean a ligament has reattached or that a knee is ready for cutting and pivoting.

Ask how each relevant outcome will be measured, how long follow-up lasts, and what would count as a meaningful improvement for your activity goals.

05 / Understand

Safety, limitations & US regulatory context

The FDA warns that regenerative medicine products marketed for orthopedic conditions may be unapproved and can carry serious risks. The applicable pathway depends on the precise product, degree of manipulation and intended use; a broad warning is not a legal determination about every procedure.

Ask for the exact product and preparation, relevant regulatory basis, evidence for your diagnosis, and a plan if symptoms or instability persist. Licensing and rules outside the United States must be checked separately.

The founder's recollection is consistent with a same-day bone marrow-derived procedure. Medical records have not independently verified the preparation. We do not identify it as BMAC or a specific Regenexx protocol.

Evidence, in context.

These assessments apply only to the named condition and outcome. Evidence strength is not a treatment safety score.

Questions to ask your clinician.

1. What exactly will be collected, processed and injected? Is it same-day material or expanded cells?
2. What evidence applies to my tear location, attachment and meniscus injury?
3. How will you distinguish MRI appearance from clinical stability?
4. What is my diagnosis, and which outcome are we trying to improve?
5. What alternatives—including rehabilitation or no procedure—are reasonable for me?
6. What complications should I understand, and how will we monitor progress?
7. What criteria would guide a return to sport, and who will assess them?

Research references.

• US regulatory guidance · 2021Important Patient and Consumer Information About Regenerative Medicine Therapies
• AAOS clinical practice guideline · 2022Management of Anterior Cruciate Ligament Injuries
• Uncontrolled human case series · 2015Anterior cruciate ligament tears treated with percutaneous injection of autologous bone marrow nucleated cells: a case series
• Randomized crossover human trial · 2025Non-surgical treatment of anterior cruciate ligament tears with percutaneous bone marrow concentrate and platelet products versus exercise therapy: a randomized-controlled, crossover trial with 2-year follow-up

Evidence and experience are different.

Read the founder's account of improved knee function, encouraging imaging and persistent instability—without treating an individual experience as proof of efficacy.