Intra-Articular Injections of Platelet-Rich Plasma in Knee Osteoarthritis: Unique Application Versus Triple Application

Osteoarthritis (OA ) refers to a clinical syndrome of joint pain with a multifactorial etiology , with the gradual loss of articular cartilage, osteophytosis formation, subchondral bone remodeling and inflammation of the joint. Is the most common cause of knee pain, and one of the leading causes of disability and dependence of the adult population that generates large expenditures in the area of health.

The clinical diagnosis of OA is primarily clinical - radiological, based on a complete medical history and physical examination directed. No laboratory studies are routinely requested since there is no specific diagnostic test or pathognomonic for diagnosis. Physical examination is most important.

The ideal treatment is a multidisciplinary one, and must meet the objectives of achieving anesthesia, reduce disability and improve joint function and patient's quality life, with low toxicity of drugs. Several conservative treatments are recommended by clinical guidelines. Some nonpharmacologic measures are: patient education, exercise, weight loss, modification of footwear, using the local cryotherapy, acupuncture and electromagnetic therapy. Drug therapy can be summarized in paracetamol, NSAIDs, opioids, and slow-acting drugs. If these oral drugs do not work can be administered intra-articularly (corticosteroids, viscosupplementation products, and blood derivates).

Platelet-Rich Plasma (PRP) is a rich source of growth factors such as Platelet-derived growth factor (PDGF), transforming growth factor β (TGF- β ), vascular endothelial growth factor (VEGF), like growth factor type I insulin (IGF- I), vascular endothelial growth factor (EGF), among others. For these growth factors are released, the platelets need to be activated by substances such as calcium chloride, calcium gluconate or thrombin. Once activated , growth factors are secreted, reaching a peak concentration 10 minutes. It is known that GF, PDGF and TGF -B stimulate chondrogenesis helping solving clinical manifestations of patients studied.

The investigators include patients attending the outpatient clinic in the area of Orthopedics and Traumatology of our hospital with a diagnosis of knee osteoarthritis, which treatment is medical. Patients will be divided into two groups. In both groups, they will be given verbal, clear and detailed information on the approach to follow, the intra-articular application of Platelet-Rich Plasma in the knee, plus rehabilitation exercises. In the first group will be held single application, while in the second group three applications will be made at an interval of two weeks each. Both groups will be assessed before and after application, together with outpatient follow-up by the SF-12, WOMAC and Visual Analogue Scale.