Two Injections That Changed Orthopaedics

PRP and TXA: One stimulates and one inhibits. Together, they have fundamentally changed the practice of orthopaedics.

Platelet Rich Plasma

PRP, standing for platelet-rich plasma, may be the most recognizable initials in orthopaedics. Platelets are the small components of the bloodstream that hold alpha granules. These are small packets that hold the proteins that act as growth factors and chemokines—factors that travel in the body and recruit other cells. This potent soup of proteins has anti-inflammatory, anti-fibrotic, and immunomodulation effects. This means that they reduce inflammation, reduce scar formation, and modify the cellular and hormonal reaction to injury and disease. Additionally, they are anabolic: They stimulate tissues to form new collagen, produce more lubrication, and affect healing. Most remarkably, they have almost no downside (though recent data shows that, when injected into muscle, they can stimulate bone formation where you don’t want it to be).

PRP, derived by spinning blood in a centrifuge, is now injected into almost all orthopaedic injuries, including arthritis, as a first-line therapy. It has been remarkably successful, despite the fact that even though well-constructed studies have shown mixed results, and that PRP is an inconsistent product. What this means is that if you draw blood and concentrate the platelets in the morning and then again in the afternoon, the two concentrations are different. Multiple different companies have PRP concentration tubes and processes. They all vary, but all seem to work reasonably well.

TXA is tranexamic acid. It is an anti-fibrinolytic agent, which means it stops the natural breakdown of new clot formation from an injury or surgery. It stops bleeding. By injecting TXA, orthopedic surgeons no longer need to use tourniquets for the vast majority of orthopaedic procedures—and often do not need to provide blood transfusions to patients, as there is minimal blood loss compared to before TXA. It is safe even for patients with a history of unwanted clot formation or bleeding disorders. By eliminating the tourniquet, a patient’s muscle recovers faster and there is less post-operative pain. Reducing bleeding also means the surgery goes faster, there is less post-operative swelling, less pain, and no risk of blood transfusion complications.

It is rare for two “drugs” to produce so much benefit and no harm. It is also my dream, as a physician and surgeon, to do the same.

Here's How We are Using PRP Injections for Joint Pain & Arthritis 

Medically authored by
Kevin R. Stone, MD
Orthopaedic surgeon, clinician, scientist, inventor, and founder of multiple companies. Dr. Stone was trained at Harvard University in internal medicine and orthopaedic surgery and at Stanford University in general surgery.