The aim of this study was to compare the efficacy of treatment in three groups of patients with knee osteoarthritis (OA) given a combination of intraosseous with intra-articular injection of platelet rich plasma (PRP), intra-articular injection of PRP and a single application of hyaluronic acid (HA).

Methods Eighty-six patients from January 2015 to June 2015 with grade II to grade III knee osteoarthritis according to the Kellgren-Lawrence classification were randomly divided into 3 groups to receive either PRP or HA. Group A received intra-articular injection of PRP 2 ml combination with medial tibial plateau and medial femoral condyle injection of PRP 2 ml (once more 2 weeks later). Group B were treated with 2 ml of PRP intra-articular injection every 14 days for a total of two injections. Group C received intra-articular injection of hyaluronic acid 2 ml every 7 days for five injections. All patients were evaluated by the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities (WOMAC) score before the treatment and at 1st, 3rd, 6th, 12th and 18th months.

Inclusion Criteria:

• Unilateral symptomatic knee with pain for at least 1 month or swelling.
• Radiographic findings of knee degeneration (Kellgren-Lawrence score of II - III).
• Age 40-73 years.
• Body mass index (BMI) 18-32.5).
• Knee stability without a severe trauma history.

Exclusion Criteria:

• Bilateral knee osteoarthritis indicative of treatment for both knees.
• Kellgren-Lawrence score greater than III.
• BMI >32.
• Age >73 years.
• Systemic autoimmune rheumatic diseases and blood disorders.
• Active immunosuppressive or anticoagulant therapy.
• Intra-articular injection to the knee within the previous 1 year or previous joint infection.
• use of corticosteroids for 3 weeks before the procedure.
• use of nonsteroidal anti-inflammatory drugs (NSAIDs) in the 3 weeks before treatment.