Knee osteoarthritis is the most common type of osteoarthritis in the lower extremity and constitutes 23% of all arthritis cases, about 13% of females and 10% of males aged above 60 years have symptomatic knee OA. Intra-articular corticosteroids (IACs) are a frequently-used treatment regimen for pain relief from symptomatic knee OA as it inhibits inflammation and reduces prostaglandin synthesis. Platelet-rich plasma (PRP) is an autologous blood product containing a high percentage of various growth factors (GFs), such as fibroblast growth factor, epidermal growth factor, vascular endothelial growth factor, transforming growth factor-β and platelet-derived growth factor. The aim of this study is to compare effect of intra-articular injection of platelet rich plasma versus corticosteroid in treatment of primary knee osteoarthritis.

Inclusion Criteria:

• Patients 40-70 years of age suffering from knee OA with Kellgren Lawrence grade II or III on standing antero-posterior and lateral knee radiographs.
• Patients diagnosed according to ACR classification criteria.

Exclusion Criteria:

• Systemic diseases as Patients having diabetes mellitus,Cardiovascular diseases or coagulopathies.
• Those receiving treatment with anticoagulant , anti_platelet medications or systemic corticosteroid 10 days before injection or recent use of NSAIDs.
• Pregnant and breast feeding females.
• Patients have hemoglobin values <10 g/dl or platelet values<150,000/ml.

Patients 40-70 years of age suffering from knee OA