Background: Platelet Rich Plasma (PRP) contains Growth Factors (GFs) and antiinflammatory agents with possibility of application in regeneration of damaged cartilage in the treatment of osteoarthritis (OA). In the most trials, three injections of PRP have been done but in this research we assessed the efficacy and safety of single injection of PRP in the management of OA.

Methods: In this single-center, uncontrolled, prospective preliminary study, 10 patients with knee OA who met the study criteria received single PRP injections. Outcome measures included the Visual Analog Scale (VAS), Knee Injury, Osteoarthritis Outcome (KOOS) questionnaire and 20 meters walk test at pre injection visit, 3 week, 2 and 6 month follow up visits.

Results: There were no adverse events. The study demonstrated significant improvements in VAS, 20 meters walk test and some KOOS scores, including pain relief and better function in daily living (ADL) but some subscale such as symptoms relief and sport activities and quality of life did not significantly improved.

Conclusion: The study showed positive results of single PRP injection and safety profile. Therefore, it could potentially be used to larger, blinded, and randomized clinical trial to determine if PRP is more effective than other treatments of knee OA or not.