PRP or Platelet Rich Plasma has hit the mainstream media. PRP is a mix of concentrated platelets and serum. Why is this important? Surgeons have known for years that healing depends on platelets. These very tiny blood components are rich in growth factors and help form a blood clot during injury. When you injure an area like a ligament or a muscle, they seep into the wound during the bleeding that normally occurs. They then set up a blood clot to stop the bleeding and start to release growth factors to the area to coordinate a repair response. Over the first week or so, they act as a time release “pill” that secretes various growth factors as various times. These time release growth factors do things like bring in stem cells and bring in new blood vessels to ensure that the body can get more blood to the area. PRP is created when the doctor takes blood from a vein and places it in a special centrifuge to concentrate platelets (usually 3-5 times their normal concentration).
To use a gardening metaphor, if you have a plant that is injured and not doing well, placing some more water and fertilizer in the ground may help your plant recover. Platelets are like fertilizer, their growth factors help rev up the local repair response. So PRP is generally good for helping things that may either heal on their own (given enough time) or are maybe stuck in the healing process and need a little “kick” to get things going towards resolution. While PRP may help recruit a few stem cells to the area, stem cell injection therapy is much more advanced. For orthopedics in particular, if PRP is like adding additional fertilizer and water to the plant, mesenchymal stem cells (MSC’s) are like placing new seeds in the area and hiring a gardener.
MSC’s are capable of not only differentiating into the new tissue that is lost, but also coordinating the repair response (so the seeds and the gardener). So, MSC therapy would be more appropriate for degenerative diseases where there is lost tissue (like chronic arthritis, a partial tenon or ligament tear, a low back disc where there are torn fibers allowing the disc to bulge). In addition, the lab prep for MSC therapy is much more complex than PRP. While PRP can be made in a simple bedside centrifuge, MSC’s are isolated from fat. The upshot, PRP is great to kick start a healing process that may be stuck, MSC’s and other stem cell approaches will likely rule the day in regenerative medicine.
Fractures that have failed to heal, joint cartilage problems, partial tears of tendons, muscles, or ligaments, chronic bursitis, avascular necrosis of the bone, and lumbar disc bulges.
Stem Cell Therapy With PRP and Tendon Injuries
Stem Cell Therapy/PRP is increasingly used in treatment of chronic non-healing tendon injuries including the elbow, patella, and the Achilles among others. As a result of mechanical factors, tendons are vulnerable to injury and stubborn to heal. Tendons also bear the responsibility of transferring a great deal of force, and as a result are susceptible to injury when they are overwhelmed. With repetitive overuse, collagen fibers in the tendon may form micro tears, leading to what is called tendonitis. The injured tendons heal by scarring which adversely affects function and increases risk of re-injury. Furthermore, tendons heal at a slow rate compared with other connective tissues, secondary to poor vascularization (blood supply).
Traditional therapies to treat these conditions do not alter the tendon’s inherent poor healing properties and involve long-term palliative care. Corticosteroids are commonly injected, however studies suggest adverse side effects including atrophy and permanent adverse structural changes in the tendon. Medications including NSAIDs, while commonly used for tendinopathies, carry significant long-term risks including bleeding ulcers and kidney damage. Thus, clinical use of Stem Cells treatments is growing.
Stem Cell Therapy with PRP and Elbow Injuries
A 2006 study in the American Journal of Sports Medicine, evaluated 140 patients with chronic epicondylar elbow pain. Of those patients, 20 were surgical candidates who had failed conservative treatments. The treatment group noted 60% improvement at 8 weeks, 81% at 6 months, and 93% at final follow-up at 12–38 months. Of note, there were no adverse effects or complications. Additionally, there was a 94% return to sporting activities and a 99% return to daily activities.
Stem Cell Therapy with PRP and Wounds
Non-healing wounds represent a challenging problem and are commonly related to peripheral vascular disease, infection, trauma, neurologic and immunologic conditions, as well as metabolic disorders.
A wound study published in the Journal of American Podiatry Medical Association 2006, involved 24 patients with 33 chronic non-healing lower extremity wounds. Patients failed conservative treatment for 6 months with a lack of reduction of surface area. The wounds were injected with PRP every 2 weeks. Successful wound closure was obtained in 20 wounds. Five wounds displayed no improvement. These findings were particularly significant because all patients had failed previously available treatment methods.
