Platelet-Rich Plasma (PRP) - Growth Factors and Stem Cells 

Platelet-rich plasma (PRP) containing growth factors and stem cells is being used more frequently in our practice for tendon irritations, tendinitis, and bursitis around the shoulder, knee, elbow, and ankle joints. Now, stem cells are also being directly added to our cartilage regeneration efforts.

Tendinitis is an inflammation of the tendon, the structure in your body that connects muscle to bone. Tendinitis can lead to degeneration of the collagen fibers that make up the tendon. The chronic pain that develops with tendinitis has been successfully treated with soft tissue massage, stretching, icing, and careful exercises. Occasionally, cortisone is used to diminish the pain but with some risk of tendon rupture. However, it may be possible to promote healing by providing the site of injury with a high level of growth factors. In a healing response, these growth factors would stimulate cells to produce new collagen and repair the injury.

The following are important points as of today:

Growth factors are normally released from platelets in the blood at the site of an injury. During an out-patient procedure in our office, we take 30 cc's of the patient's own blood, spin down the platelets in a centrifuge, chemically and/or physically induce them to release their growth factors, and then inject them into the site of injury.

These steps stimulate a healing response and raise the concentration of growth factors to 4 - 8 times the levels that normally circulate in the blood.

The effectiveness of this procedure is promising and still uncertain. Definitive outcome studies are underway. Studies that support the use of growth factors are referenced at the end of this article. The three key factors most commonly studied are: TGF-B (transforming growth factor-B), PDGF-AB (platelet-derived fibroblast growth factor), and bFGF (beta fibroblast growth factor). Studies on injection of these factors from the platelets in peripheral blood have focused on accelerating the healing process and reducing pain in Achilles tendon repair studies. One such study in chronic elbow tendinitis demonstrated a 93% reduction of pain.

When placed into a treated arthritic area and stimulated with motion, stem cells from adult bone marrow produce growth factors and form cells that can develop into cartilage. At The Stone Clinic, we have used the paste grafting technique for repairing arthritic cartilage in knees and ankles for the past 17 years and have recently demonstrated the percentage and activity of progenitor cells in the paste. In studies, stem cells have been shown to develop into cartilage cells and produce relevant growth factors. Further studies are underway at the Stone Research Foundation to optimize the performance of stem cells by adding additional growth factors. Paste grafting remains a key technique to biologically reconstruct injured and arthritic knees.

Stem cells, combined with full articular cartilage grafts and a transplanted meniscus allograft, represent a new method to re-build severely arthritic knees. We refer to this as "biologic knee reconstruction" rather than "bionic" or "artificial knee replacement." Biologic knee reconstruction is performed as an outpatient arthroscopic procedure and avoids some of the risks and limitations of artificial joint knees. We have recently submitted for publication our 2 - 11-year follow-up studies of the first 106 patients who have undergone our combined biologic knee reconstruction. The results show a solid 79.2% success rate with a predicted survival rate of 9.6 years.