High Frequency Intensive Autologous PRP Injection and Genicular Nerve Blocks in Treating Knee Osteoarthritis

Osteoarthritis (OA) of the knees is the most common degenerative disorder seen in a rehabilitation outpatient clinic. It is characterized by structural changes in the articular cartilage and the surrounding tissues. The understanding of its pathophysiology is still unclear. Knee OA patients are often troubled with knee pain and functional disturbance. Several studies have shown that the earlier the injection of autologous platelet rich plasma (PRP) to treat early stages of knee OA, the better the treatment outcome. However, there are controversies as to whether PRP injections can also be effective in treating patients with moderate to severe degrees of knee OA. Synovial fluid (SF) is in contact with the primary tissues affected by OA (cartilage and synovium). Identifying the SF biomarkers can provide us with crucial information in monitoring the PRP treatment response. PRP is blood plasma that is rich in autologous platelets. Platelet releases growth factors and cytokines that can stimulate the healing of soft tissue structures. However, the amount of platelets in human blood is not concentrated. Purification and centrifugation procedures are needed to concentrate these platelets. The human knee cartilage is contained inside the knee joint and has scarce blood supply. When the cartilage is injured, growth factors can hardly reach this area to repair the cartilage. Therefore, many studies have suggested early usage of PRP in treating knee OA. Some studies have stated that the effect of PRP in treating knee OA is superior to that of hyaluronic acid (HA). Recent studies have recommended the application of high frequency PRP injections (ex/ intra-articular (IA) PRP injections on a weekly basis) in treating patients with more severe degrees of knee OA. Prolotherapy using hyperosmolar dextrose solution has been shown to have some positive effectiveness in treating patients with knee OA. Higher percentage, such as \> 12.5% of dextrose water, may stimulate cartilage repair