This is a single-center, randomized control trial The aim of this study is to compare PRP with placebo as the treatment of knee OA Conducted at Puri Raharja Hospital Bali in January-June 2022 Sample consisted of 106 patients with knee OA grades 2-3 Kellgren-Lawrence, randomized into PRP group and placebo group Samples were injected with 2 ml PRP or normal saline twice at one-week interval The severity of knee OA was assessed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) before injection and two weeks after the first injection.

Inclusion Criteria:

patients with knee pain for at least three months, aged between 40 to 80 years old, and whose results of radiological examination of the knee indicated OA grades 2-4 based on the Kellgren Lawrence classification

Exclusion Criteria:

polyarticular rheumatic disease; knee arthroscopy <1 year; intra-articular injection of hyaluronic acid (HA) or steroids in the past three months; current infection, diabetes, rheumatoid arthritis, coagulopathy disorders, anticoagulant or antiplatelet aggregation therapy, immunodeficiency disease, taking non-steroidal anti-inflammatory drugs (NSAIDs) two weeks prior to the procedure, knee trauma; inflammation; and tumors around the knee