Editorial Commentary: Platelet-Rich Plasma or Profit-Rich Placebo: Variability of Composition, Concentration, Preparation, and Many Other Yet-Unknown Factors Determine Effectiveness.

Platelet-rich plasma (PRP) frequently is used in orthopaedics, and its application is supported by clinical studies for a variety of conditions. For knee osteoarthritis, it is more effective than hyaluronic acid, providing significant better pain relief and functional improvement. However, different compositions of PRP, absolute platelet counts, and many other physiological and demographic variables will influence the effectiveness. Variability of the composition of the ingredients of PRP surely has a substantial influence on outcome.