Classification of platelet concentrates (Platelet-Rich Plasma-PRP, Platelet-Rich Fibrin-PRF) for topical and infiltrative use in orthopedic and sports medicine: current consensus, clinical implications and perspectives

Abstract

Platelet concentrates for topical and infiltrative use -commonly termed Platetet-Rich Plasma (PRP) or Platelet-Rich Fibrin (PRF) -are used or tested as surgical adjuvants or regenerative medicine preparations in most medical fields, particularly in sports medicine and orthopaedic surgery. Even if these products offer interesting therapeutic perspectives, their clinical relevance is largely debated, as the literature on the topic is often confused and contradictory. The long history of these products was always associated with confusions, mostly related to the lack of consensual terminology, characterization and classification of the many products that were tested in the last 40 years. The current consensus is based on a simple classification system dividing the many products in 4 main families, based on their fibrin architecture and cell content: Pure Platelet-Rich Plasma (P-PRP), such as the PRGF-Endoret technique; Leukocyte-and Platelet-Rich Plasma (L-PRP), such as Biomet GPS system; Pure Platelet-Rich Fibrin (P-PRF), such as Fibrinet; Leukocyteand Platelet-Rich Fibrin (L-PRF), such as Intra-Spin L-PRF. The 4 main families of products present different biological signatures and mechanisms, and obvious differences for clinical applications. This classification serves as a basis for further investigations of the effects of these products. Perspectives of evolutions of this classification and terminology are also discussed, particularly concerning the impact of the cell content, preservation and activation on these products in sports medicine and orthopaedics.

The in vitro release of cytokines and growth factors from fibrin membranes produced through horizontal centrifugation

“…[3][4][5][6] Among those materials, leukocyte-and platelet-rich fibrin (L-PRF) membranes belong to the second generation of platelet aggregates. [3][4][5][6] Among those materials, leukocyte-and platelet-rich fibrin (L-PRF) membranes belong to the second generation of platelet aggregates.…”

“…These factors promote regeneration through processes such as angiogenesis and stimulate the migration and proliferation of osteoblasts, fibroblasts and mesenchymal cells. 3,13 This system uses a fixed-angle rotor centrifuge to process a 9 mL aliquot of peripheral blood for 10 min. As these mediators can impact both positively and negatively on the clinical outcome of its use in several treatments, they remain a controversial subject in the scientific literature.…”

Platelet rich plasma for photodamaged skin: A pilot study

“…However, the final number of platelets in the PRP product is not always proportional to the final number of growth factors, and optimal concentrations are not known . Nonetheless, the lack of scientific rigor in studies evaluating the clinical effects of PRP has not gone unnoticed; some have proposed various classification systems to improve standards for documentation in studies to facilitate comparison of results . Unfortunately, no system incorporates all of the differing properties of PRP and the influence of their emphasized variables on the efficacy of PRP has not been definitively established, which may explain why these systems have yet to be widely adopted.…”

Adult Cells Combined With Platelet-Rich Plasma for Tendon Healing

“…8 It has been widely used in orthopaedics and sports medicine to manage tendon conditions. 2 However, after meta-analysis of current clinical studies, several authors agreed that its efficacy is still controversial.…”