Article Type

Original Study


Objective The aim of this study was to determine the regenerative properties of intra-articular injections of autologous platelet-rich plasma (PRP) in improving knee osteoarthritic patients and to determine the correlation of platelet count and transforming growth factor-β1 (TGF-β1) with clinical improvement. Background Platelets have an important role in primary as well as secondary hemostasis; however, its regenerative capability is not widely studied. Osteoarthritis (OA) is a cartilage degenerative process. No treatment is available to improve this process. Patients and methods The study was conducted on 28 patients suffering from primary knee OA grades II and III injected with PRP preparation after failure of conservative treatment. Patients received two injections 3 weeks apart, and then were followed up for 6 months using the Western Ontario and McMaster Universities Arthritis Index and radiography. Platelet count and TGF-β1 were measured in PRP to ensure platelet activation and release and to evaluate their role in improvement of the condition. Results At the end of follow-up period, there were no adverse events reported and all Western Ontario and McMaster Universities Arthritis Index parameters were significantly improved. Better results were recorded in patients with a low degree of cartilage degeneration (P = 0.004). Platelets and TGF-β1 showed a highly significant increase in PRP compared with their basal level (P < 0.001). Patients achieving an excellent response had statistically higher platelet counts and TGF-β1 in PRP. To predict excellent response to PRP, platelet count in PRP had a cutoff of 1001.25 × 109/l, whereas TGF-β1 had at a cutoff concentration of 128.25 ng/ml. Conclusion Intra-articular injection with autologous PRP is a safe, minimally invasive, low-cost procedure to deliver growth factors for cartilage healing and regeneration. Hence, it is useful for the treatment of OA of the knee, aiming to reduce pain and improve knee function and quality of life. Platelet count and TGF-β levels in PRP are important predictors of improvement.