Original article can be accessed here http://www.ncbi.nlm.nih.gov/pubmed/23299850

BACKGROUND: Specific growth factors have been proposed as therapeutic proteins for cartilage repair.

HYPOTHESIS: Platelet-rich plasma (PRP) provides symptomatic relief in early osteoarthritis (OA) of the knee.

STUDY DESIGN: Randomized controlled trial; Level of evidence, 1.

METHODS: A total of 78 patients (156 knees) with bilateral OA were divided randomly into 3 […]

http://www.orthohealing.com/wp-content/uploads/2012/03/PRP-AJPMR-OA-apr-12.pdf to read an original research article pn the treatment of Knee Joint Osteoarthritis with Autologous Platelet-Rich Plasma in Comparison with Hyaluronic Acid.

Comparison Between Hyaluronic Acid and Platelet-Rich Plasma, Intra-articular Infiltration in the Treatment of Gonarthrosis

http://www.recreationmedicalcentre.com.au/wp-content/uploads/2014/08/Cerza_2012.pdf