Efficacy and Safety of Intra-articular Injections of Frozen Platelet-Rich Plasma in Patients With Knee Osteoarthritis

Inclusion Criteria: * Patients of both sexes. * Aged between 40 and 85 years old. * Diagnosed with osteoarthritis through clinical radiological examination. * Joint pain equal to or less than 75 points on the KOOS (pain). * Radiological severity grades 1, 2, and 3 according to the Ahlbäck scale. * Indication for intra-articular PRP infiltration. * Body Mass Index values between 20 and 35. * Negative serological tests for syphilis, HIV, HBV, and HCV. * Possibility of observation during the follow-up period. * Signature of informed consent. Exclusion Criteria: * Body mass index \>35 * Diagnosed polyarticular disease. * Previous arthroscopy in the last year. * Severe mechanical deformity. * Intra-articular hyaluronic acid injection in the last 12 months. * Intra-articular corticosteroid or PRP injection in the last 6 months. * Systemic autoimmune rheumatic disease (connective tissue diseases and systemic necrotizing vasculitis). * Anemia or other hematological disorders. * Positive serological tests for SYPHILIS, HIV, HBV, and HCV. * Undergoing immunosuppressive treatments. * Poorly controlled diabetes mellitus. * Patients allergic to paracetamol. * Pregnancy or breastfeeding.