This study aimed to analyze the effect of platelet-rich plasma (PRP) on knee osteoarthritis. Eligible patients will undertake arthroscopic knee surgery plus intraoperative PRP and also receive second look surgery and intraoperative biopsy.

Osteoarthritis is a chronic disease defined by progressive degradation of the joint as well as loss of cartilage on joint surfaces. The degeneration that occurs in the joint leads to changes in the catabolic and anabolic activity of chondrocytes. Osteoarthritis may induce pain, stiffness and limitation in range of motion of the joint and also may impact the quality of life. Platelet-rich plasma (PRP) is a fraction of plasma that contains platelets and multiple growth factors concentrated at high level. Because activated platelets have the potential to release growth factors, PRP has been clinically used to accelerate wound healing and tissue regeneration in orthopedic and oral surgery. Although several studies have assessed the effects of PRP on knee osteoarthritis, a higher level of evidence has not been provided. This study aimed to analyze the effect of PRP on knee osteoarthritis. After performing arthroscopic knee surgery plus intraoperative PRP in eligible patients, a second look arthroscopic surgery with intraoperative biopsy will be arranged 6 months later. Pre- and post-operative imaging and clinical outcomes will also be compared.

Inclusion Criteria:

• Age between 30 and 70 years
• With diagnosis of osteoarthritis, grade II~grade IV, II-III medial compartment

Exclusion Criteria:

• Lateral compartment and patellofemoral joint osteoarthritis
• With prior history of knee surgery
• Severe varus deformity
• With current or prior history of traum or infection at the knee
• With current or prior history of cancer
• With current or prior history of hematological disease
• Pregnancy
• Patients who will not cooperate with one-year followup