Regenerative Medicine

Regenerative medicine, also known as “orthobiologics” is the process of replacing or regenerating cells, tissues or organs to restore or establish normal function. Regenerative medicine also empowers scientists to grow tissues and organs in the laboratory and safely implant them when the body cannot heal itself.  The Nobel Prize in medicine for 2012 was granted to two researchers for their work with regenerative techniques.

Biologically, all cells start from a stem cell, similar to a plant starting from a seed. Stem cells are in all tissues in the body, thus allowing old and damaged cells to be replaced. Each stem cell divides into either more stem cells, or it differentiates to become specialized. We can grow muscle by placing stem cells into a petri dish of muscle, while the same stem cells placed in petri dishes of bone become bone. And while impressive, we need to remember what stem cell researcher Dr. Arnold Caplan said. “People are excited about stem cells, and well they should be, but it is not the stem cell, but the environment which is most important.”

When do we consider regenerative medications? It depends on the diagnosis, use of the horse, and the client’s preferences. What is the process? First, we need an accurate diagnosis. The body as a whole needs evaluation. Where is the pain, what tissue, is it primary or secondary?  Then, we need to be aware of any mechanical interferences which are preventing healing.  Some examples of mechanical interferences are severe conformational abnormalities, non-union bone fractures, overriding dorsal spinous processes, excessively low hoof/pastern axis, amongst other possible diagnoses. After careful diagnostics, treatment options are discussed with you, the owner.   When orthobiologics are considered, we have three options: Platelet Rich Plasma, Autologous Conditioned Serum / IRAP, and Stem Cells

Autologous Conditioned Serum, (ACS) is a composite of blood proteins, specifically Interleukin-1 receptor antagonist protein and some growth factors.  It functions by counteracting the damaging effect of inflammatory proteins which are present in an arthritic joint.  Recent work has shown some growth factors present in ACS, although fewer than in PRP.

Preparation:  ACS  is prepared by removing blood from a horse into special syringes containing glass beads. After centrifugation and 24 hours of refrigeration, there is a concentration of protein ready to be injected into the joint. Joints are usually injected once a month for three times, sometimes once a week for four treatments.

A common indication to use IRAP would be osteoarthritis.

Comparison between PRP and ACS:

PRP is more cost effective, takes less time to prepare so treatments can be done the same day of diagnosis, and need one injection into the damaged area as opposed to 3-5 injections.

Stem Cells

Stem cells are the originators of all the cells in the body and they change into specialized cells when “directed” so by the environment. In the following picture, the stem cells in the middle become all of the six peripheral cells, and this is just a few of the cells which stem  cells can become! Amazing. Just think of how different the environment must be to influence such cell diversity!

STEM CELL PREPARATION

When it is decided to use stem cells, the stem cells are procured either from the bone marrow or the fat from the hip region. In human and veterinary medicine, it is unclear whether bone marrow or fat derived stem cells are more advantageous, but we know that both tissue yield high levels of stem cells.  At CEC, we prefer to harvest stem cells from the bone marrow because we can keep these cells in their same environment, concentrate them, and while they are still in their “home” environment, inject them within two hours into the damaged tissue.

The process is after identification of the body and tissue depth of a sternal bone using ultrasound, sterile preparation and local anesthesia of the tissue. A large bore needle with a marked stylet is used to bore into the bone. Next, 2 – 3cc of heparin is injected into the bone as bone marrow clots very fast, and then 60cc of bone marrow is removed. The location is bandaged, and the 60cc of bone marrow stem cell is centrifuged. As in preparation of platelet rich plasma, stem cells have a specific weight and thus can be concentrated with centrifugation by special equipment.

These cells are then injected into the joint or tendon, or even used as a regional limb perfusion. Stem cells can “hone” which means they migrate to the area where they are needed, and differentiate into the cell type needed in that area.   Some clinicians send stem cells to labs to grow the stem cells into larger numbers before injecting.  It is yet unknown how many stem cells are needed to produce the desired effect.

FACTORS FOR SUCCESS FOR ORTHOBIOLOGIC TREATMENTS

As in any treatment of the musculoskeletal system, several factors are involved to achieve the optimal success:

• An accurate diagnosis to include examination of the whole horse
• Preparation of the PRP using advanced centrifuges
• Injection using sterile technique and ultrasound guidance to assure accurate location of PRP
• Physical therapy post injection
• Recognition and treatment of mechanical interferences

CONTRAINDICATIONS

The use of biologics is contraindicated in horses that are septicemic (have a systemic infection), have received corticosteroid injections at the same site within the past two weeks, have recently been feverish or ill, or have a low systemic platelet count. The risk of worsened pain or reduced function is very low in both humans and horses—significantly lower than the risks associated with corticosteroid joint injections. While temporary pain at the injection site may occur, it is rare. For PRP to be effective, it must be injected directly into the lesion; otherwise, it will not have the desired effect. Ultrasound-guided injections are crucial to ensure PRP is accurately deposited into the damaged tissue rather than surrounding healthy tissue. The risk of infection is extremely low.

SUMMARY

In summary, regenerative medicine may represent the future of medical treatment. Why not harness the body’s natural ability to activate cell activity and produce new cells using the animal’s own biological resources? By creating the right environment for these active progenitor cells to function, we provide both the conditions and the tools for healing. This concept is similar to providing a plant seed with water, warmth, nutrients, and soil to grow.

In severe cases of osteochondrosis dissecans, the combination of PRP and stem cells has shown better outcomes than surgery, injectable medications like Adequan or hyaluronic acid, or steroids. Since 2008, Colorado Equine Clinic has treated over 345 cases, addressing more than 850 areas, including tendons, joints, hoof cracks, laminitis, and draining fistula tracts, using PRP with or without stem cells. The results have been longer-lasting, with shorter recovery times and significant pain reduction lasting several years. In some cases, horses have required no further treatment for years.

However, each case is unique, and client needs and goals vary. We are grateful to have access to these regenerative therapies, especially given the superior clinical outcomes we’ve observed. These results reinforce the value of considering orthobiologics as a viable option for treating musculoskeletal injuries in horses.