title: Effectiveness of Biologic Factors in Shoulder Disorders.
abstract: BACKGROUND
  Shoulder pathology can cause significant pain, discomfort, and loss of function that all interfere with activities of daily living and may lead to poor quality of life. Primary osteoarthritis and rotator cuff diseases with its sequalae are the main culprits. Management of shoulder disorders using biological factors gained an increasing interest over the last years. This interest reveals the need of effective treatments for shoulder degenerative disorders, and highlights the importance of a comprehensive and detailed understanding of the rapidly increasing knowledge in the field.
  
  
  METHODS
  This study will describe most of the available biology-based strategies that have been recently developed, focusing on their effectiveness in animal and clinical studies.
  
  
  RESULTS
  Data fromin vitrowork will also be briefly presented; in order to further elucidate newly acquired knowledge regarding mechanisms of tissue degeneration and repair that would probably drive translational work in the next decade. The role of platelet rich-plasma, growth factors, stem cells and other alternative treatments will be described in an evidence-based approach, in an attempt to provide guidelines for their clinical application. Finally, certain challenges that biologic treatments face today will be described as an initiative for future strategies.
  
  
  CONCLUSIONS
  The application of different growth factors and mesenchymal stem cells appears as promising approaches for enhancing biologic repair. However, data from clinical studies are still limited, and future studies need to improve understanding of the repair process in cellular and molecular level and evaluate the effectiveness of biologic factors in the management of shoulder disorders.
authors.affiliation: Department of Trauma & Orthopaedic Surgery, University of Ioannina, Ioannina, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Giotis
authors.affiliation: Department of Biomedical Engineering, University of California, Davis, USA.
authors.forename: Ashkan
authors.initials: A
authors.lastname: Aryaei
authors.affiliation: Department of Trauma & Orthopaedic Surgery, University of Ioannina, Ioannina, Greece.
authors.forename: Theofanis
authors.initials: T
authors.lastname: Vasilakakos
authors.affiliation: Department of Trauma & Orthopaedic Surgery, University of Ioannina, Ioannina, Greece; Department of Biomedical Engineering, University of California, Davis, USA.
authors.forename: Nikolaos K
authors.initials: NK
authors.lastname: Paschos
keywords: Biologic factors; Effectiveness; Growth factors; Healing; Osteoarthritis; Platelet rich-plasma; Rotator cuff; Stem cells