SPECIAL REPORT

Among the many challenges to musculoskeletal health, tendinopathy and osteoarthritis (OA) are extremely common, and can lead to frequent pain and reduced function. The problem is likely to be intensified by current trends, including the growing epidemic of injuries in sports. In truth, while the number of sports practitioners increases, the rate of sports injuries distressing the musculoskeletal system is growing and becoming a challenging problem. For example, people who participate in sports have an increased risk of joint injuries, hence OA is common among former professional athletes or sports practitioners aged over 50 years [1]. Furthermore, 30–50% of the injuries among professional and recreational athletes are overuse tendon injuries, so tendinopathy has become one of the most exasperating problems for patients and physicians in orthopedic sports medicine [2]. Accordingly, both conditions have substantial impact on quality of life, including disabilities with widespread economic consequences, as post-traumatic OA costs more than US$12 billion annually [3]. At present, no available therapeutic options have been able to delay the progression or reverse chronic recalcitrant tendinopathy and joint damage, thus worsening prognosis and involving pessimistic social and economic implications. Among the emerging technologies for enhancing and accelerating tissue healing, a biocompatible and cost-effective approach, broadly referred to as platelet-rich plasma (PRP) therapy, involves the use of autologous activated platelets retained in fibrin matrices as a source of healing molecules [4]. Nowadays, PRP therapies represent a major breakthrough in the treatment of many medical conditions and are one of the hottest topics in orthopedics owing to their presumed healing properties. The underlying principle of PRPs is to deliver a large pool of signaling proteins such as growth factors and other cytokines to the local milieu driving the tissue regeneration mechanisms [5,6]. The impact of the discoveries regarding the potential of PRP in regulating multiple biological processes, such as cell proliferation or the modulation of angiogenesis, and inflammation has fuelled the optimism regarding autologous PRP treatments. Contributions in the field have not only improved the clinical treatment of many patients with different clinical conditions but, from a multimolecular perspective, have opened the field of PRP science to cellular and molecular exploration of healing mechanisms. This article briefly reviews the important progress that has been accomplished in the field of PRP in chronic musculoskeletal conditions in the last few years. The main components of PRP products and their impact in healing mechanisms, the most exciting applications in rheumatology and the existing current challenges will be discussed.