Riordan Medical Institute’s Stemnexa protocols combine the latest scientific advances in bone marrow harvesting with two complimentary cellular technologies: Bone Marrow Aspirate Concentrate (BMAC) and amniotic tissue product. Possible effects of Stemnexa include:

  • shorter healing times
  • increased vascularization
  • less pain for the patient
  • increased safety rate with the harvesting method
  • reduced inflammation
  • decreased risk of infection

Stemnexa-Rx is the alternative to surgery which provides a simple, elegant solution to difficult problems.

Stemnexa-Sx combines advanced orthopedic surgical procedures with cell therapy with the desired objectives of better patient outcomes.

Stemnexa incorporates:

  • The harvesting process using a patent applied for device
  • Bone Marrow Aspirate Concentrate (BMAC™)
  • Amniotic Tissue Products

Harvesting Bone Marrow

The Bio-MAC® Bone Marrow Aspiration Cannula harnesses the latest scientific innovation in safe bone marrow harvesting. This revolutionary new system for obtaining autologous (one’s own) stem cells is safer and less painful for the patient than conventional bone marrow harvesting procedures.

A leading feature of the Bio-MAC is the gentle insertion process. This delivery system minimizes the potential for microfracturing, bruising and subsequent pain from ‘pounding’ or ‘forcing by hand’ other marrow aspiration cannulas into bone.

Learn more: A New Standard in Bone Marrow Harvesting for Stem Cell Therapy in Orthopedics: Bio-MAC at Riordan Medical Institute

This special device and catheter system enables bone marrow harvesting in an outpatient setting under local anesthesia with minimal patient discomfort.

The entire process takes about 10 minutes.

Is it Painful?

For patients who are awake and under local anesthesia, there is some pain but it is not intolerable. It’s uncomfortable more than it is painful. The patient can feel when the doctor starts the draw but that pain is usually tolerated very well; only lasting for somewhere between 3 and 5 minutes.

If the patient is under general anesthesia for a stem cell-enhanced surgery or they choose conscious sedation for a non-surgical procedure, there is no pain.

Afterwards, most patients don’t even know where the bone marrow was taken out until they discover the stitch. It’s rare that anyone experiences any tenderness at the collection point.

Bone Marrow Aspirate Concentrate™

BMAC comes from your own bone marrow and contains a wealth of cells which can aid the body in its own recovery.

BMAC can be highly effective for bone, muscle, tendon, ligament and cartilage injuries. Bone marrow is an excellent source for the cells and growth factors that are responsible for the healing and tissue regeneration process.

At RMI, we employ a vertical axis centrifuge specifically calibrated to produce bone marrow concentrate (BMAC) in order to maximize results.

How Much Bone Marrow is Needed?

Normally we draw 60 – 120 cc (2 – 4 ounces) of bone marrow.

The surgeon creates a small round hole using a patented cannula attached power driven device that eliminates impaction (pounding) trauma. This device is attached to the BioMAC catheter, which was developed to draw the bone marrow out from the bone.

Is Bone Marrow Safe?

Because BMAC is autologous, meaning it comes from the patient’s own body, the likelihood of any adverse side effects due to the BMAC itself is exceedingly low. To-date, there have never been any reports of adverse side effects.

The Science Behind BMAC

BMAC contains mesenchymal stem cells (MSC), CD34+ stem cells, growth factors and (mesenchymal) trophic factors (MTF).

  • MSC reduce inflammation, regulate the immune system and secrete factors that stimulate tissue regeneration. The better the blood supply, the faster surgical wounds and orthopedic injuries will heal and the more conducive the environment will be for MSC to flourish.
  • CD34+ stem cells are blood-forming cells. They induce blood vessels to grow (angiogenesis). CD34+ stem cells are the most angiogenic cells in the body.
  • Growth factors in BMAC are capable of stimulating cellular growth, proliferation, healing and differentiation (changing into another type of cell such as a blood vessel cell).
  • Mesenchymal Trophic Factors (MTF) are secreted by MSC. Most of the benefits commonly attributed to MSC (see above), are actually due to the trophic factors they secrete.

Amniotic Tissue Products

Amniotic tissue product is a pliable allograft (transplant) derived from human placental amnion, which functions as a biologic structural matrix to facilitate and enhance tissue healing and repair.

Amniotic tissue has been used since 1910 in the US and is now FDA-exempt for treating wounds and other conditions. It was first used for treating eye problems, primarily corneas and is still widely used in ophthalmology today.

Once the baby is born, the placenta along with the amniotic sack and what’s left of the umbilical cord come out. It’s called afterbirth and is usually discarded.

Amniotic tissue is procured this from contracted hospitals after normal, healthy births. Once it has been fully tested for infectious diseases, sterility and a few other things, the tissue is processed.

Using proprietary technology, the tissue is separated into very small particles that are cryo-preserved in a special way that keeps the integrity of the tissue the same as it was when it came out after the healthy birth of the child.

How do some amniotic tissue products augment a patient’s bone marrow stem cells?


The cells on the left, which were cultured with amniotic tissue product, have the morphology of young, healthy MSCs. No flattening, a red color of mitochondria, and they’re spread throughout the whole cell body. On the right, you’ll notice in cells that were not cultured with amniotic tissue product, the cells are flat and fibroblastic looking. They are becoming senescent, the last step before they stop producing growth signals and can do nothing but basically form scar tissue.

The Amniotic Tissue Product Advantage

  • Reduces inflammation and pain
  • Provides growth factors
  • Supports regeneration
  • Enhances stem cells
  • Heals wounds
  • Reduces fibrosis risk
  • Reduces adhesion
  • Immune privileged

Amniotic Tissue Product Safety

Other than occasional pain and swelling at the injection site, we have not observed any adverse side effects from amniotic tissue products.

The amniotic membrane is immune-privileged so the patient’s immune system can’t recognize it as a foreign substance.

The Science Behind amniotic tissue products for Inflammation, Pain and Wound Healing

Amniotic membrane provides structural support and a plethora of growth factors. Some products derived from amniotic membrane have as many as 108 growth factors that are cryo-preserved. The two most important are:

  • Prostaglandin
  • WNT4

Prostaglandin inhibits inflammation, which occurs after injury and marks the beginning of the healing process. The faster we can tame this inflammation, the sooner the body can move on to the next phase of healing, regeneration. The product we use has more than 60 times as much prostaglandin than competing products.

WNT4 is arguably the single most important molecule required for wound healing. The product we use has more than 60 times as much WNT4 as competing products.

The amniotic tissue product we use contains Interleukin-1 receptor antagonists and Tissue Inhibitor of Metallo-proteinase 1, 2, 3 and 4 proteins that suppress and modulate inflammation and subsequent pain.

The Science Behind Stem Cells, Regeneration and Growth Factors

In addition to its pain and inflammation reduction and wound healing properties, the right amniotic tissue product can create an environment that is conducive to stem cell proliferation. It contains important growth factors including PDGF, VEGF, EGF, FGF and TGF-B, which promote collagen matrix formation and cellular proliferation while minimizing the formation of scar tissue.

  • The product we use is composed of collagens and other structural proteins, which provide a biologic matrix that supports angiogenesis, tissue growth and new collagen during tissue regeneration and repair.


View/download the entire chapter about stem cell therapy for orthopedic conditions from Dr. Riordan’s book

For more detailed information about our treatments, we welcome you to read/download the entire chapter on stem cell therapy for orthopedic conditions from Dr. Riordan’s new book, Stem Cell Therapy: A Rising Tide – How Stem Cells are Disrupting Medicine and Transforming Lives.  CLICK HERE (FREE PDF)

“Neil takes readers on a riveting journey through the past, present and future of stem cell therapy. His well-researched, educational and entertaining book could change your life. I highly recommend it.”Tony Robbins, NY Times #1 Bestselling Author

“100 years old will soon become the new 60. Stem cells are a key therapeutic to enable this future. Dr. Riordan’s book is your guide to why this is true and how you will benefit. A must read for anyone who cares about extending their healthy lifespan.”Peter H. Diamandis, MD; Founder, XPRIZE & Singularity University; Co-Founder, Human Longevity, Inc.; Author of NY Times Best Sellers Abundance and Bold