BioMed Research International Platelet Rich Plasma and Orthopedics: Why, When, and How Guest Editors: Mikel Sánchez, Giuseppe Filardo, and Tomokazu Yoshioka Platelet Rich Plasma and Orthopedics: Why, When, and How BioMed Research International Platelet Rich Plasma and Orthopedics: Why, When, and How Guest Editors: Mikel Sanchez,GiuseppeFilardo,´ and Tomokazu Yoshioka Copyright © 2015 Hindawi Publishing Corporation. All rights reserved. This is a special issue published in “BioMed Research International.” All articles are open access articles distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Contents Platelet Rich Plasma and Orthopedics: Why, When, and How,MikelSanchez,´ Giuseppe Filardo, and Tomokazu Yoshioka Volume 2015, Article ID 949720, 2 pages New and Emerging Strategies in Platelet-Rich Plasma Application in Musculoskeletal Regenerative Procedures: General Overview on Still Open Questions and Outlook, Francesca Salamanna, Francesca Veronesi, Melania Maglio, Elena Della Bella, Maria Sartori, and Milena Fini Volume 2015, Article ID 846045, 24 pages PRP Augmentation for ACL Reconstruction, Luca Andriolo, Berardo Di Matteo, Elizaveta Kon, Giuseppe Filardo, Giulia Venieri, and Maurilio Marcacci Volume 2015, Article ID 371746, 15 pages PRP and Articular Cartilage: A Clinical Update, Antonio Marmotti, Roberto Rossi, Filippo Castoldi, Eliana Roveda, Gianni Michielon, and Giuseppe M. Peretti Volume 2015, Article ID 542502, 19 pages Hyperuricemic PRP in Tendon Cells,I.Andia,E.Rubio-Azpeitia,andN.Maffulli Volume2014,ArticleID926481,8pages Platelet Rich Plasma and Knee Surgery,MikelSanchez,´ Diego Delgado, Pello Sanchez,´ Nicolas´ Fiz, Juan Azofra, Gorka Orive, Eduardo Anitua, and Sabino Padilla Volume2014,ArticleID890630,10pages Are Applied Growth Factors Able to Mimic the Positive Effects of Mesenchymal Stem Cells on the Regeneration of Meniscus in the Avascular Zone?, Johannes Zellner, Christian Dirk Taeger, Markus Schaffer, J. Camilo Roldan, Markus Loibl, Michael B. Mueller, Arne Berner, Werner Krutsch, Michaela K. I. Huber, Richard Kujat, Michael Nerlich, and Peter Angele Volume2014,ArticleID537686,10pages Regenerative Medicine in Rotator Cuff Injuries, Pietro Randelli, Filippo Randelli, Vincenza Ragone, Alessandra Menon, Riccardo D’Ambrosi, Davide Cucchi, Paolo Cabitza, and Giuseppe Banfi Volume 2014, Article ID 129515, 9 pages Platelet Concentration in Platelet-Rich Plasma Affects Tenocyte Behavior In Vitro,IlariaGiusti, Sandra D’Ascenzo, Annalisa Manco,` Gabriella Di Stefano, Marianna Di Francesco, Anna Rughetti, Antonella Dal Mas, Gianfranco Properzi, Vittorio Calvisi, and Vincenza Dolo Volume2014,ArticleID630870,12pages Clinical Applications of Platelet-Rich Plasma in Patellar Tendinopathy,D.U.Jeong,C.-R.Lee,J.H.Lee, J. Pak, L.-W.Kang, B. C. Jeong, and S. H. Lee Volume2014,ArticleID249498,15pages Does Platelet-Rich Plasma Freeze-Thawing Influence Growth Factor Release and Their Effects on Chondrocytes and Synoviocytes?, Alice Roffi, Giuseppe Filardo, Elisa Assirelli, Carola Cavallo, Annarita Cenacchi, Andrea Facchini, Brunella Grigolo, Elizaveta Kon, Erminia Mariani, Loredana Pratelli, Lia Pulsatelli, and Maurilio Marcacci Volume 2014, Article ID 692913, 10 pages Hindawi Publishing Corporation BioMed Research International Volume 2015, Article ID 949720, 2 pages http://dx.doi.org/10.1155/2015/949720 Editorial Platelet Rich Plasma and Orthopedics: Why, When, and How Mikel Sánchez,1 Giuseppe Filardo,2 and Tomokazu Yoshioka3 1 Arthroscopic Surgery Unit, Hospital Vithas San Jose,´ 01008 Vitoria-Gasteiz, Spain 2Biomechanics Laboratory-II Clinic, Rizzoli Orthopaedic Institute, 40136 Bologna, Italy 3Division of Regenerative Medicine for Musculoskeletal System, Department of Orthopaedics Surgery, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan Correspondence should be addressed to Mikel Sanchez;´ [email protected] Received 2 February 2015; Accepted 2 February 2015 Copyright © 2015 Mikel Sanchez´ et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In present practice, orthopedic and sports medicine is mak- howtouseitaswell.Wehavetorememberthatthisisnot ing a great effort in promoting the use of minimally invasive a magical bullet. We should know the possible indications techniques aimed at arresting or slowing down the aging and foritsuseandthevolumetobeapplied,thefrequency degeneration of several tissues. The scientific community has of application, number of applications, and so forth. PRP been developing new areas of research that have fuelled the applicationforanacuteinjurylikeabonefractureisdifferent emergence of regenerative medicine and tissue engineering from treating a chronic injury such as a tendinopathy and bringing into the spotlight treatments such as those based on different again from approaching a degenerative problem stem cells and platelet rich plasma (PRP). Growing interest such as osteoarthritis. This lack of consensus is the reason for in PRP is evident. Since PRP therapies began to be used the title of this special issue. regularly in the musculoskeletal system at the onset of this Studies presented in this special issue cover topics ranging decade, this topic has now reached over 7000 publications from preclinical to clinical research of PRP technology in the scientific literature. When delving into the published in different tissues. I. Giusti and I. Andia conducted two research studies and reviews, two overwhelming facts stand in vitro studies about PRP and tendon cells. The former out over the rest: a maze of clinical indications based on evaluated the tenocyte cellular behavior with different platelet widely varied and even controversial results and a relative dif- concentrations; I. Andia et al. analyzed the effect of uric ficulty in establishing a mechanistic cause-effect relationship, acid in tendon cells response to PRP. Continuing the tendon facts that are fueling a rather misleading controversy. pathology, D. U. Jeong et al. reviewed the clinical effectiveness The root of PRP controversy lies in several inconsistencies of PRP in the patellar tendinopathy, and P. Randelli et al. including a lack of standardization in obtaining PRP as an addressed the treatment of rotator cuff injuries with PRP autologous product. PRP contains by definition a platelet as well as stem cells. A. Roffi and A. Marmotti focused on concentration superior to peripheral blood. In recent years, PRP application for cartilage and its pathologies. The former a plethora of platelet concentration systems has been com- studied the effect of PRP cryopreservation on its quality and mercialized, and these are marketed under different names its action over chondrocytes and synoviocytes. The latter andacronymsbuttheyareallsoldundertheumbrella updated the clinical knowledge of PRP in chondral surgery term “PRP.” The final biological products are very distinct in and in the treatment of cartilage degenerative processes. In terms of volume, color, platelet count, presence or absence of this special issue, there are also three articles related to knee leukocytes, and unknown protein content; and the activation pathology. J. Zellner et al. carried out both in vitro and in method, with either bovine thrombin or calcium chloride, vivo assays in order to study the effect of PRP and BMP7 adds more confusion to this biologic ceremony. The question in meniscal defects. L. Andriolo et al. presented a systematic we must ask is whether PRP is a homogeneous consistent review about biological effects of PRP in the reconstruction of biological product. Not only is it important to have a fully the anterior cruciate ligament. In addition, M. Sanchez et al. characterized and reproducible product, it is crucial to know showed a series of PRP application guidelines for several knee 2 BioMed Research International surgeries. Finally, F. Salamanna et al. conducted an extensive literature review of preclinical studies with PRP in different musculoskeletal tissues. AsBertoltBrechtwroteinLife of Galileo “The aim of the science is not to open the door to infinite wisdom but to set a limit to infinite error”, these works are only afew examples of the larger number of studies still needed to answer questions that give name to this special issue. We are at the nascent end of a new health technology and, as it happened in the era of antibiotics, we must lead to a future in which PRP should be characterized both for each patient and for each application protocol. And as it happened many times in the history of medicine, we are constantly passing through the three phases described by Schopenhauer: “All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self- evident.”However, we realize that now we face the paradox of Socrates: we know that we know nothing. Therefore, further studies about PRP as presented here are necessary to keep shedding light on this topic. Mikel Sanchez´ Giuseppe Filardo Tomokazu Yoshioka Hindawi Publishing Corporation BioMed Research International Volume 2015, Article ID 846045, 24 pages http://dx.doi.org/10.1155/2015/846045 Review Article New and Emerging Strategies in Platelet-Rich Plasma Application in Musculoskeletal Regenerative Procedures: General